[cctalk] Re: TVs [was: Pragmatically [was: Experience using an Altair 8800 ("Personal computer" from 70s)]

[Mike Katz via cctalk]

I believe that place on Elston was either Joseph Electronics or The 
American Science Center depending on whether is was in Chicago or Niles.


On 5/28/2024 8:06 PM, CAREY SCHUG via cctalk wrote:

We spent 64-65 in japan, bought a TV, brought it back, channels were different, 
so i bought a surplus tv tuner at that place on elston in Chicago an replaced 
it.  These were tubes.

I started in electronics taking apart the 8" tv we were given, which had two 
complete chassis, each with a hefty power supply, mostly full size tubes, IIRC.

--Carey

[cctalk] Re: Pragmatically [was: Experience using an Altair 8800 ("Personal computer" from 70s)]

[Mike Katz via cctalk]

Fred,

I'm sorry but those arguments are religion to most of us and the clear 
answer has already been decided (tongue firmly implanted in cheek)


1.  Between Vi and EMACS - Any editor where you have a cursor movement 
mode that is separate from edit mode (since the invention of arrow keys 
or the control key) just isn't a real editor.
2.  Between Big Endian and Little Endian - Big endian is easier to read 
for us dumb humans but little endian was easier to implement on early 
hardware.
 I want to add to this argument and ask Is bit 0 the high order bit 
(like on the PDP-8) or the low order bit (like on the 6809)?

3.  Between the 6502 and the Z-80 the 6809 wins hands down every time.

As for the first personal computer, no one has been able refuted my 
claim that the Antikythera Mechanism is not only the first Personal 
Computer but also first portable computer 藍


On 5/28/2024 5:10 PM, Fred Cisin via cctalk wrote:

On Tue, 28 May 2024, Sellam Abraham via cctalk wrote:

How about can we be done with this now? :D


Sorry, but "FIRST" and "PERSONAL" are permanent topics,
along with emacs V VI, big-endian/little-endian, Mac/PC,
6502/Z80, etc.

[cctalk] Re: terminology [was: First Personal Computer]

[Mike Katz via cctalk]

Paul, you said:/
/

/I'd say an OS is a software system that runs on bare metal (or 
equivalent, like a VM) and offers a set of services intended to make 
creating and running applications easier. In that sense, RT-11 SJ or 
OS/360 PCP are operating systems, just as Linux is. QRQ is on the edge 
(it's written for a single application). Similarly, I would not call 
FIG-FORTH an OS, nor those other FORTH systems, though admittedly it's 
also a bit fuzzy. /

If the file system and basic I/O functions drivers are in ROM what is the 
difference between a BIOS and an Operating System.

Technically speaking, for some, the BIOS offers a hardware abstraction level to some more 
generic software that runs on top.  BIOS means Basic Input Output System.  Is that 
restricted to the console only?  Some systems run their entire "Operating 
System" out of ROM?

Let's take a very simple computer, the HP-41C Calculator.  The internal 12K or ROM 
handled all of the keypad I/O, display I/O, math functions and programming functions.  
Each device added contained all of it's drivers in ROM.  There was never an 
"Operating System" to load but with additonal hardware/software modules even 
reading and writing to floppy disks and mini data cassettes was supported.  The 12K main 
ROM and how the expansion hardware/ROM integrated into it was definitely an operating 
system.

On the IBM-PC most boards (that were not just multi I/O or RAM boards) came with their 
own drivers in ROM as well and were even called bios extensions.  The big difference 
between the PC and the HP-41C that the PC needed to load the file system handler (and 
others as time when on) from disk to run.  Whereas the HP-41C never needed to 
"bootstrap" from some kind of media.

By your definition many BIOS's are really operating systems.  And if I really 
want to pick nits, what you defined as an Operating System is really an 
application that uses the BIOS Operating System.  Yes, I know, not all BIOS's 
have enough functionality to qualify as an operating system.

To spark even further debate, does an operating system require file system 
capabilities.  Many do not.  This furthers my supposition that the BIOS is 
really the operating system and what you are calling an operating system is 
merely an application using the BIOS API for the required services.

My comments are not intended to inflame but rather to cause further discussion.




On 5/28/2024 2:38 PM, Paul Koning via cctalk wrote:



On May 28, 2024, at 3:24 PM, John via cctalk  wrote:

From: ben
To:cctalk@classiccmp.org
Subject: [cctalk] Re: terminology [was: First Personal Computer]


The third thing is a real OS. Nobody has one, as a personal computer.
CP/M and MSDOS does not handle IRQ's. Unix for the PDP-11 is real
operating system but not personal as it requires a admin,and a
swapping media.

This an auld refrain among *nix partisans of the ESR type, but I've yet
to hear someone offer up a real defense of it. Even putting aside what
"handles IRQs" means here (yes, strictly speaking the IRQs on the IBM
PC are handled by the BIOS and/or add-on drivers/utilties, but DOS most
certainly makes use of the facilities provided,) why does that make it
"not a real OS?" What does PDP-11 Unix provide which MS-DOS doesn't to
make one "real" and the other not?

Certainly, nothing about a single-tasking single-user text-based
environment *requires* interrupt-based I/O, even if it may smooth out
performance in some aspects. ...

Or is it multi-tasking capability itself that makes the difference?
Can't see why that should be the case; it's definitely convenient, but
as one person can only be doing so much at any given time, it's also
hard to see that as a *requirement.*

So what, then, consitutes a Real Operating System, and why?

Is RT-11 a "real operating system"?  What about RT-11 SJ?  I would consider it 
to be one.

For that matter, what about OS/360 PCP?  That's a single task OS, just like 
RT-11 SJ only much less efficient.

Is FIG-FORTH an OS?  What about POLYFORTH or ZeptoFORTH?

The picture gets particularly muddled when you look at RTOS.  For example, it's 
well known in hard real-time OS that using interrupts is not necessarily a good 
plan.  A very successful storage system I worked on ran on a dual core MIPS 
system.  One core ran NetBSD; the other ran a home-grown RTOS called QRQ that 
used a polling loop (and no priorities) rather than interrupts.  The benefit of 
such a design is that its time bounds are easy to establish, unlike interrupt 
driven systems where that is certainly harder and not always possible at all.

I'd say an OS is a software system that runs on bare metal (or equivalent, like 
a VM) and offers a set of services intended to make creating and running 
applications easier.  In that sense, RT-11 SJ or OS/360 PCP are operating 
systems, just as Linux is.  QRQ is on the edge (it's written for a single 
application).  Similarly, I would not call FIG-FORTH an OS, nor those other 

[cctalk] Re: terminology [was: First Personal Computer]

[Mike Katz via cctalk]

OS/9 was an incredible operating system for an 8 bit machine.  Level 1 
was a bit limited. But level II,  which could address a megabyte of 
memory or more, supported multiple tasks, users and intelligent 
peripherals.  It supported applications in ROM and RAM and made full use 
of all of the advanced capabilities of the 6809 CPU.


It was a little bit of a memory hog because code written for it had to 
be written as position independent code.  On the 6809 this could take up 
more RAM because some of the relative instructions required 16 bits or 
more to decode.



On 5/26/2024 5:49 PM, Fred Cisin via cctalk wrote:
"Real OS"?  While I don't agree with your specific examples of 
inadequacies, I will readily concede that nothing so far is ready 
for the title.


On Sun, 26 May 2024, ben via cctalk wrote:
CP/M was the cats meyow in the 1970's,but there was other systems out 
like
flex for the 6800, or later OS/9 for the 6809. Don't they get a 
chance too for real OS.


OS/9 was kinda cool, but my Cocos were kinda inadequate hardware to 
make full use of it.



Randy Cook tried to make a "real OS" for the TRS80.  But, he never 
FINISHED [nor documented] TRSDOS, nor VTOS.  When LSI commissioned 
LDOS, as the finishing of TRSDOS/VTOS, they stripped out a lot of the 
"real OS" features that Randy Cook had intended, but never finished 
implementing.
But, when Radio-shack licensed LDOS, to be TRSDOS 6.0, Randy Cook 
finally started to receive royalties.


--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: terminology [was: First Personal Computer]

[Mike Katz via cctalk]

i'm sorry but you are misinformed about the HP-41C Calculator.

The HP-41 was the first calculator that had Alpha-Numerics.  It could 
very well give text descriptions, text prompts and even manipulate 
text.  It also had a full goto and gosub to alphanumeric labels.


It had a very sophisticated programming language that could be user 
enhanced in both user (FOCAL [No Relation to DEC's Focal]) language and 
machine language.


The user community enhanced the user language through the use of 
"Synthetic Programming".  This is creating additional user commands not 
originally implemented by HP.


It came with four expansion slots built into it for RAM, ROM and 
peripherals.


It supported several different file systems in both RAM and digital media.

There was a forth interpreter available for it as well.

Here is a list of some of the peripherals available for it (I know there 
are way more than this list):


Direct Plug In:
    Magnetic Card Reader
    Bar Code Reader
    20 Column Thermal Printer
    HI-IL (2 wire network)
    EEPROM Box for Machine Code
    RAM Box for Machine Code
    Additional Program Memory
    Extended Memory
    ROM Module for user code and machine code (both from HP and user 
written).

HP-IL Peripherals
    20 Column Thermal Printer
    80 Column Ink Jet Printer
    Digital Magnetic Tape Drive
    3 1/2" Floppy Disk Drive
    RS-232 Interface
    IEE-488 (GPIB) Interface
    Video Interface (40 column, 80 column, graphics)
    HP-IL Interface for Epson MX-80 dot matrix printer
    Digital Multimeter
    Frequency Counter
    20 Channel Data Acquisition Box

The CPU had a 10 bit instruction word with a 56 bit data word.  With a 
Harvard Architecture (separate RAM and ROM address spaces).  The RAM 
address space was 8192 8 bit bytes.  The ROM address space was 65536 10 
bit words.  With paging the machine code address space was expanded to 
192K maximum)


That hardly sounds like just a calculator to me.  It could be called the 
first Pocket PC.




On 5/26/2024 4:14 PM, CAREY SCHUG via cctalk wrote:

if it only manipulates numeric data, it is a calculator.  It must be able to 
search, rearrange look up, compare, and display characters.  I would have 
thought that to be obvious.  I don'care if it has 99 terabites of high speed 
memory and does fourier transforms in minus 0 seconds, if it cannot give a text 
description of the answer, it is a calculator.

Also something about arbritray branches to any location (ok, any executable 
location if something has separate code and data memory).

--Carey


On 05/26/2024 3:01 PM CDT Chuck Guzis via cctalk  wrote:

  
On 5/26/24 11:11, ben via cctalk wrote:

On 2024-05-26 10:56 a.m., Fred Cisin via cctalk wrote:
I did use a CP/M machine once, but the 8" drive was a bit sticky.
You rap the drive to get it unstuck, but if you rap it too hard
the machine would reset.

Fred, just forget it.  We belong to a bygone era and there's no sense in
trying to explain things to the younger folk.

However, perhaps someone can tell me why an HP-41 or TI SR-52 isn't a
"personal computer"...

--Chuck

[cctalk] Re: First Personal Computer

[Mike Katz via cctalk]

You see, we are back to my original comment.  The definition of Personal 
Computer is quite fluid.  Does it have to be called a Personal Computer 
in advertising literature or does any computer that can be used by a 
single person, in any environment, constitute a personal computer.


If i am writing the definition than my original comment that the 
Antikythera Mechanism is the first computing device designed to be used 
by a single person..


To someone else the Altiar is the first personal computer.  And to yet, 
someone else an early PDP or HP computer might be the first personal 
computer.


There are many mechanical and later analog computing devices in use long 
before the modern digital computer.  What about the Hollerith Machine 
used to count the census from the 1890's to the 1950's.  It was a one 
person calculating machine but since it was used for commercial purposes 
does that make it a personal computer.  When IBM initially released the 
first PC it was intended not for home use but for business use (for 
$10,000 1980's dollars).  The Northstar Horizon was also marketed as a 
business computer but used by home S-100 hobbyists.


The point, as I stated earlier, is that for every different definition 
we will find a different result.


I guess this means that the definition of personal computer is personal

This is written with tongue firmly implanted in cheek.

On 5/25/2024 1:27 PM, Jon Elson via cctalk wrote:

On 5/25/24 13:05, CAREY SCHUG via cctalk wrote:
When announced and sold new, were the SIMON, LINC and G-15 sold and 
described as, in the exact words, "personal computer"?  Did the guy 
with multiple supercomputers in his basement buy them NEW, to use 
them for their designed purpose?  If not they are just memorabilia, 
like a victrola.


The Bendix G-15 came out in 1956!  It cost about $60,000 in 1956 
Dollars.  The first LINC machines were built at an MIT summer school 
by grad students who would then take them back to their home 
institutions and use then in biomedical research labs.  The LINCs in 
this case cost about $50K, and were built starting in 1961-62.  The 
term "personal computer" was not coined until a LONG time after.


Jon

[cctalk] Re: terminology [was: First Personal Computer]

[Mike Katz via cctalk]

I'm sorry but I beg to differ with you here.  The DEC PDP line of single 
user interactive computers (as opposed to batch processing only systems) 
started in the late 1950's and early 1960's and spawned many generations 
as well as copies and other companies (Data General being the most well 
known of these).Yes multi user time sharing operating systems we added 
later on but initially they were single user interactive, (DEC 10 & 20 
excepted).Does a computer lose its "Personal" identification if it can 
handle multiple users as an option. There were multiple user time 
sharing Operating Systems for many early personal computers (Unix, 
Xenix, MP/M, Uniflex, OS/9, etc.). Even the aforementioned PDP computers 
ran multi-user time sharing systems. Does that, then, invalidate them 
for consideration as a personal computer? Does that make any Linux 
machine not a personal computer, by definition, because it can handle 
more than one user or task? As I have said earlier in this thead and its 
fore bearers, the term Personal Computer is so non-specific that we can 
argue from here to Alpha Centauri and back without coming up with an 
agreed upon definition. So, until a concrete definition can be made, the 
discussion of the answer is completely moot. I stick by my original 
challenge, find a calculating device that predates the Antikythera 
Mechanism (36 BCE). Simple measuring devices like the sun dial and 
sextant don't count as they don't calculate, they measure.

On 5/25/2024 4:26 PM, CAREY SCHUG via cctalk wrote:

(Rick--IIRC, some later Curta (knockoffs?) could do square roots too, is that 
true, do you have one?)

OK, I'll loosen up, or make exceptions.

Maybe some devices before the altair used the exact or inexact words "personal 
computer".

but they did not "create a market" or lead directly to a series of similar, competing 
products, and do not come anywhere close to what we think of as a "personal computer" 
now.  The Altair is very different from a modern personal computer, but still has more similarities 
and a continuous chain of intermediate stages.  Part of what makes a personal computer to us is 
that we can easily switch from one to another.  That would not have been possible between the 
LGP-30, LINC, etc.

I still ask the question, what fraction of the G-15, LINC, IBM 610, Programma 101, etc, 
were purchased as "personal" devices by an individual, for personal use, and 
from household funds rather than via a corporate (including educational) purchase-order?

Other terminology:

IIRC the first computers that were sold as "supercomputers" were scalar, maybe with a few 
more processors than the generation before, but programmed in the same manner.  Then shortly came 
the massively parallel "supercomputers" created from commodity microcomputer chips, and 
the term supercomputer has transitioned to mean them.

--Carey


On 05/25/2024 3:33 PM CDT Rick Bensene via cctalk  wrote:

  
While the LGP-30(vacuum tube/drum), G-15(vacuum tube/drum), and PB-250(transistor/delay lines) predated it, the ground-breaking Olivetti Programma 101(transistor/delay line) programmable desktop calculator was officially called a "personal computer" in some of its advertising and sales literature.  It was introduced in October of 1965.


Late in the game as far as single-user, standard AC-line-powered computing devices 
compared to those machines and probably others, but those machines, AFAIK, were not 
advertised nor specified as "personal computers".
   
That said, I am much more aware of electronic calculator history than computer history, so I could be entirely biased here.  Also, the Programma 101, as I've stated here before, only scratches the definition of a true computer in that it is not capable of handling any data type but floating point binary-coded decimal numbers, has very limited data storage capability, and had no peripheral interfacing capability.


There were quite a number of single-user computing devices made and sold that ran on 
standard AC power, and were vastly more capable than the Programma 101, and predated it, 
but, AFAIK, were not advertised or particularly marketed as "personal 
computers".

One that comes to mind is the Monroe Monrobot III(vacuum tube/drum), introduced 
in February, 1955.

Another is the IBM 610 "Auto Point"(vacuum tube/drum) computer, introduced in 
1957.
It was originally named the "Personal Automatic Computer" (PAC) by its designer.

I'm sure that there are quite a few other machines developed in the mid-to-late 
1950's that would qualify as personal computing devices, but these two are the 
ones that I'm aware of that seem to fit the bill.   Some of these may actually 
have been capable of manipulating data types other than decimal numbers.

In 1962, Casio introduced its AL-1 programmable (up to 360 steps) relay-based 
electric calculator.  It was definitely intended as a personal computing 
device, and calculations could be performed manually from a keyboard much 

[cctalk] Re: First Personal Computer

[Mike Katz via cctalk]

Now that is an interesting refinement.  Limiting to 1800 VA, most likely 
eliminates almost anything vacuum tube based.


My 1974 PDP-8/E computer alone (not counting external storage devices) 
was rated at 115V @ 10A.  I don't know what the power factor of it is 
but that is 1150 Watts.  Does that count? Technically I don't need any 
peripherals to program it or get the program results.  I just use the 
front panel.


Does that 1800VA include any necessary peripherals such as terminals, 
CRT's, disk drives, tape drives, etc?


See, even that definition is really non-specific and open to interpretation.

Should we add a limitation on volume occupied as well?  This would 
eliminate many rack or multiple rack computers.


What about memory type?  Before semiconductor RAM and CORE there was 
serial, drum, tape and mechanical memory systems


Does it have to be a digital computer.  There we many table top analog 
computers in the 50's and 60's.  Even Heathkit made some.


Does the output need to be text (What about an analog computer with a 
digital nixie tube display)???


Everyone has their own definition of what a Personal Computer is to 
them.  It's all subjective.


How much computing power and electricity are we using trying to identify 
something whose mere definition is so subject to interpretation?


On 5/25/2024 4:57 PM, Chuck Guzis via cctalk wrote:

On 5/25/24 13:41, Fred Cisin via cctalk wrote:

On Sat, 25 May 2024, Chuck Guzis via cctalk wrote:
. . . or 100V or 220V in locations where those are the standard for
household residential wiring.
Woulld not want to automatically exclude UK machines, such as the
Sinclair doorstop wedge.

Okay, I'll refine it for the international crowd.  Anything that
requires over 1800 VA to run isn't a "personal computer"  That's about 8
amps for the 220 volt world.

--Chuck

[cctalk] Re: Help? Programming SCM90448 EPROMs

[Mike Katz via cctalk]

I have an old Logical Devices Inc, Gangpro 8 with DIP sockets on it.  
What package is this part?  Is it compatible with anything more widely 
known?


On 5/25/2024 12:23 PM, Glen Slick via cctalk wrote:

On Sat, May 25, 2024 at 6:27 AM emanuel stiebler via cctalk
 wrote:

Hi all,
anybody in the US could program some SCM90448 EPROMs for me?
None of my programmers I have here, can do it.

Some old, trusty DATA I/O ???

What is an SCM90448? Can you find a datasheet for that part? I cannot.

[cctalk] First Personal Computer

[Mike Katz via cctalk]

The problem with this debate is that the definition of Personal Computer 
is totally fluid and can be written so that the writers opinion is fact.


Each computer system has contributed, in some way, to those that followed.

If you really want say what is the first "personal" computing machine 
that did not require manual manipulation (like an abacus) it would have 
to be the Antikythera Mechanism.


This orrery (model of the solar system) was built around 35 BC.  Yes is 
was an analog computer but technically it was the first personal 
computer (single user, autonomous, hand held and portable too).


https://www.scientificamerican.com/article/an-ancient-greek-astronomical-calculation-machine-reveals-new-secrets/
https://en.wikipedia.org/wiki/Antikythera_mechanism

Ok, all of you computer brains out there, find me something older that 
matches this (I'm sorry but the sun dial, sextant and compass don't 
count because they don't calculate they only indicate).


Tongue firmly implanted in cheek 


On 5/24/2024 11:14 AM, Sellam Abraham via cctalk wrote:

On Fri, May 24, 2024 at 8:34 AM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:


On 5/24/24 07:57, CAREY SCHUG via cctalk wrote:


(I could be mistaken about the mentioned 8008 device, but I think that

was a training device, no?)

Do your homewoork--the MCM-70 ran APL, had cassette storage and a
display and keyboard.  The MITS 8800 had nothing other than RAM and a
CPU.  APL would have been a distant dream.

Of course, the MCM0/70 was Canadian, and not USAn...

--Chuck


This is on the Canonical List of ClassicCmp Debate Topics and is a dead
horse so beaten that there's nothing left but teeth and fur at this point.

Sellam

[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)

[Mike Katz via cctalk]

When my wife (now my ex-wife) told me during a move that my 2 PDP-8/E 
racks were not going to the new apartment because there wasn't room for 
her roll top desk and my computer.  And told me "they go or you go with 
them but they are not moving with us", I should have seen the signs and 
gone with them.


That would have saved me a bunch of money in the divorce AND I would 
still have those beautiful PDP-8's.


I'm still trying to recover from that one.

On 5/23/2024 7:04 PM, Fred Cisin via cctalk wrote:

On Thu, 23 May 2024, Chuck Guzis via cctalk wrote:

I couldn't wait to show it to a female working in my section.  She
dropped by my apartment, took one look at the thing sitting on my
kitchen table and burst out laughing.  "That's not a computer; it's a
toy!" was her withering reaction.
I don't know if my male ego ever recovered from that.  And I *hated* the
DRAM boards.


Be very thankful that it was before you had more invested in the 
relationship.


I almost failed to heed the warning (although FAR less personally 
humiliating), when a new interest thought that "Hitchhiker's guide To 
The Galaxy" was "stupid".



--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Random items on Pascal #6

[Mike Katz via cctalk]

Nicholas Wirth in his paper on Modula-2 about fixing the flaws in Pascal.

In planning Modula-2, I saw it as a new version of Pascal, updated to 
the requirements of the time, and I seized the opportunity to correct 
various mistakes in Pascal’s design, such as, for example, the syntactic 
anomaly of the dangling “else”, the incomplete specification of 
procedure parameters, and others. Apart from relatively minor 
corrections and additions the primary innovation was that of modules.




On 5/9/2024 3:45 PM, Fred Cisin via cctalk wrote:

OK
This seems to be the one that the list choked on
(possibly due to special quote characters?

On Thu, May 9, 2024, 2:07 AM david barto via cctalk 
 wrote:

At Ken Bowles retirement from UCSD (Ken was the lead of the UCSD Pascal
Project) he related a story that IBM came to UCSD after being "rejected"
by DR to see if the Regents of the University would license UCSD 
Pascal (the

OS and the language) to IBM for release on the new hardware IBM was
developing. The UC Regents said "no"
He was quite sad that history took the very different course.


well, it wasn't quite a "rejected by DR".  But, the culture clash 
certainly did strengthen IBM's desire for CP/M alternatives.  And, 
they DID cut a deal with Softech/UCSD-Regents to have UCSD P-system as 
one of the original operating systems for the 5150.
The "very different course" of the market going with CP/M and MS-DOS, 
rather than P-System, was due to many factors.


--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: FWIW CD & DVD demagnitizitation [was: Double Density 3.5" Floppy Disks]

[Mike Katz via cctalk]

This is an article on it but I still think it's total bunk:

https://www.gcaudio.com/tips-tricks/cd-dvd-demagnetization/

On 5/9/2024 9:04 AM, Antonio Carlini via cctalk wrote:

On 09/05/2024 14:28, Alexander Schreiber via cctalk wrote:

German snake oil wizards to the rescue! The "Atomstromfilter" (nuclear
power filter) joke product has been making the rounds in Germany for
at _least_ 20+y now:https://traumshop.net/produkt/atomstromfilter/

It claims to filter power generated by nuclear power plants out of
your power flow at the wall socket ;-)



Sorry, but that's clearly rubbish: it's way, way too cheap. Mind you, 
there are none on eBay UK, so maybe I could put some up at a bargain 
price ... £3500 too much?



(I was going to add  a tin foil hat too, to save on postage, but those 
are already on eBay :-()



Antonio

[cctalk] Re: APL (Was: BASIC

[Mike Katz via cctalk]

There is scientific proof that studying music helps with math aptitude 
and vice versa.


On 5/8/2024 9:30 AM, Paul Koning via cctalk wrote:



On May 8, 2024, at 10:25 AM, Harald Arnesen via cctalk  
wrote:

Paul Koning via cctalk [07/05/2024 19.31]:


(Then again, I had a classmate who was taking a double major: math and music 
composition...)

Mathemathics and music is not a rare combination - see Tom Lehrer, for instance.
--
Hilsen Harald

My wife (a voice major) pointed out that instrumental music majors tend to be 
good at math; voice majors not so much.

paul

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

I also have one of those from Radio Shack that I have had for more than 
30 years.


On 5/6/2024 8:30 PM, Chuck Guzis via cctalk wrote:

On 5/6/24 15:12, Fred Cisin via cctalk wrote:

Radio Shack used to sell a "Bulk Tape Eraser".  I gave mine to the college.
Those are on eBay, and even Amazon.


I've had one of those for years. Resembles a kitchen Mixmaster without
the beaters.   The problem is that it has a limited working period of
about a minute before it gets too hot and the thermal cutout stops the fun.

--Chuck

[cctalk] Re: 5,34 Petaflop System Cheyenne

[Mike Katz via cctalk]

I wonder if some intermediary is buying it for a country that cannot 
legally purchase something like that from the USA.


I'm not normally a conspiracy guy but why would any normal company pay 
half a million dollars for something that could be produced with today's 
technology for considerably less?


On 5/3/2024 6:57 PM, Gavin Scott via cctalk wrote:

Sold at $480,085.00.

On Fri, May 3, 2024 at 6:22 PM Gavin Scott  wrote:

On Fri, May 3, 2024 at 5:14 PM Liam Proven via cctalk
 wrote:


Bad news...

But does he have 8,000 of them haha.

Auction is at $435K now (past the end time) with multiple active
bidders extending it.

[cctalk] Re: CP/M

[Mike Katz via cctalk]

CP/M (Originally Control Program/Monitor later Control Program for 
Microcomputers) we developed by Gary Killdall in at Digital Research, 
Inc.  1974.

CP/M-86 was released in 1981.
CP/M-68K was released in 1982.





On 5/3/2024 7:11 PM, Norman Jaffe via cctalk wrote:

Not quite.
CP/M is not a rename of PL/M.
PL/M is a derivative of the programming language PL/I and was used in the 
development of CP/M - it is not an operating system.
CP/M-86 was a later development of CP/M that was designed to run on 16-bit 
Intel processors.
CP/M-68K was another branch of CP/M for use with Motorola 68K processors.

From: "Murray McCullough via cctalk" 
To: "cctalk" 
Cc: "Murray McCullough" 
Sent: Friday, May 3, 2024 4:46:54 PM
Subject: [cctalk] CP/M

I came across an article that said CP/M came out in April 1974. I remember
using this OS in the microcomputer world in the late 70’s; early 80’s. It
came from PL/M, (Programming Language for Microcomputers) later renamed
CP/M(Control Program for Microcomputers). I’m not sure what its legacy is
though as far as I can recall it was wrapped up in litigation for quite
some time. It was used in the 8-bit world but not sure what it's role was
in the early PC world!

Happy computing,

Murray 

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

On 4/30/2024 4:07 PM, Wayne S via cctalk wrote:

What kind of floppies did Hp recommend to use with this drive?

Sent from my iPhone


On Apr 30, 2024, at 13:55, Fred Cisin via cctalk  wrote:

On Tue, 30 Apr 2024, John Herron via cctalk wrote:

Yup, that's all I used to do. Some scotch tape over the floppy disk hole to
make the system see it as DD. If it didn't automatically format as 720, you
could specify size or sector count with format.com in dos.

Somemedia sensors are optical; use opaque taps.


I did hear folks say it wasn't always reliable (similar to 5.25 disks being
formated on a high density drive) but I never saw any problems in my
limited use.

3.5" are 600 VS 750 oersted;
5.25" are 300 vs 600 Oersted;
a low density 5.25 formatted as "high density" won't do well;
a high density 5.25" (1.2M) formatted as low density ("360K") sill self erase VERY soon, sometimes 
before you can even get it over to another machine.  We had a college purchasing agent in bed with 
"Roytype", who kept giving us "1.2M" floppies ofr out TRS80s; they self erased very soon.

--
Grumpy Ol' fredci...@xenosoft.com

[cctalk] Re: BASIC

[Mike Katz via cctalk]

Microsoft loves to take languages developed by others and transmogrify 
them into the "Microsoft Universe".


Quick Basic, Visual Java, Visual Basic, Visual C# (barely resembles C) 
and the worst offender of all Visual C++ .NET.


Your post reminded me that Postscript is an actual programming language 
as well.




On 5/2/2024 11:24 AM, Chuck Guzis via cctalk wrote:

I'll add a postscript with my reaction upon seeing my first Microsoft
Visual BASIC program code:

"What the hell is this?  It's not BASIC!"

--Chuck

[cctalk] Re: What to take to a vintage computer show

[Mike Katz via cctalk]

I had a similar experience at VCF Midwest where the line voltage was as 
low as 90 VAC.  My area was without power for about 2 hours during setup.




On 5/2/2024 11:01 AM, Douglas Taylor via cctalk wrote:
I learned at VCF East this year that I should have brought an UPS to 
make sure that my vintage equipment had good, clean AC power.  My 
PDP11 kept on resetting during the show.

Doug

On 5/1/2024 9:53 PM, Brad H via cctalk wrote:

Just reaching out to anyone who has exhibited at a vintage computing
festival before.  After years of only being able to watch others 
attend the
ones that happen in the US, we are finally getting one in BC here.  
Super
excited.  I was invited both to speak and to exhibit, and they even 
got me

two tables which is awesome.


Like, how do you prepare for these things?  What things that you didn't
think of going into your first show do you wish you had?


I have a pretty eclectic collection, and some really rare stuff (like my
Mark-8s) that I'd love to bring but am hesitant about due to the 
risks of

transportation damage and theft (from the car mostly, not the convention
itself).  Just trying to decide what to bring and how focused to be 
in terms

of theme.


Brad

[cctalk] Re: BASIC

[Mike Katz via cctalk]

Fred,

It's not a big deal.  I was exposed to the DTSS as a 7th grader because 
I was going to a boarding school near by in 1972.


The school I was at had a PDP-8/L and I became an early adopter computer 
geek.


On 5/1/2024 6:05 PM, Fred Cisin via cctalk wrote:

On Wed, 1 May 2024, Mike Katz wrote:
I'm sorry but the original BASIC as run on the Dartmouth Time Sharing 
System was compiled.


I wasn't around Dartmouth, and my first experiences with BASIC were 
all interpreted.


I had run a trivial program in it on a Silent 700 connected through a 
phone line, long before I got my first personal computer (TRS80).



Thank you for the details of the history.


When Microsoft introduced "BASCOM" (their BASIC compiler), my first 
uses of it were primarily to make my source code less easily 
accessible to would-be infringers. :-)



--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: APL (Was: BASIC

[Mike Katz via cctalk]

I remember replacing the character generator eprom (the type with the 
window for UV erasing) on an old ATI EGA video board so that I could 
have the APL character set.


On 5/1/2024 7:14 PM, Fred Cisin via cctalk wrote:

APL was incredible.  I was amazed.  I was immediately able to do a few
simple things that were useful for my boss and myself, and writing
simple programs within hours.  Its matrix arithmetic was awesome. APL
typeball on a selectric terminal at GSFC, . . .
Some of the keys were re-labeled, but there was a chart on the wall of
which keyboard characters were which APL symbols.


On Wed, 1 May 2024, Chuck Guzis via cctalk wrote:

It was indeed.  It was also one of the first languages implemented on a
microprocessor-based personal computer system.  (MCM-70).
To me, APL is logical--strict right-to-left precedence; simple array and
matrix operations.
I've long wondered if we introduced students to APL as a first language,
what our applications code would look like today.
My friend Bruce, called it "That Iverson Language".
It's interesting to note that the Iverson book was published in 1962,
but an implementation (under 7090 IBSYS) didn't come about until 1965,
although preliminary implementation as PAT had been done on a 1620 (!)
in 1963.


The extended character set was an important obstacle to its 
acceptance. Besides keyboard (masking tape) and output (APL typeball, 
special character generator, or having to substitute combinations of 
character), many people were unwilling to even try something with a 
different character set.


--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: BASIC

[Mike Katz via cctalk]

I'm sorry but the original BASIC as run on the Dartmouth Time Sharing 
System was compiled.


On 5/1/2024 5:26 PM, Fred Cisin via cctalk wrote:

On Wed, 1 May 2024, Murray McCullough via cctalk wrote:

Nostalgia keeps pressing ahead: It was 60 yrs. ago that BASIC came into
existence. I remember very well writing in Apple Basic and GW Basic 
later
on. As a non-compiled OS, an interpreted OS, it was just the right 
tool for

a microcomputer with  limited memory. I recall fondly taking code from
popular magazines and getting them to run. It was thrilling indeed!
Happy computing,
Murray 


BTW, BASIC ("Beginners All-purpose Symbolic Instruction Code") was 
developed at Dartmouth college by Kurtz and Kemeny.  More than 30 
years later was the first time (or so they claimed) that they EVER got 
around to trying ANY of the BASICs based on their original language.

They were APALLED!
They came out with "TRUE BASIC", to counter the various "street BASICs.


picky details, . . . BASIC was a non-compiled interpreted LANGUAGE, 
not an OS ("Operating System"), at least in the examples you mention.  
(also TRS80 and some models of Commodore)



However, to be fair, there did exist something called "Microsoft 
Stand-Alone BASIC", used in the Coco, some models of NEC 8801 (and 9801?)
That was a Microsoft BASIC that had rudimentary disk operations built 
in, to serve the needed functions of an OS.
The disk directory structure of Microsoft Stand-Alone BASIC, with 
directory entris pointing into a linked list allocation table,was the 
inspiration for Tim Paterson to use as the directory structure for 
PC-DOS/MS-DOS/86-DOS/QDOS ("Quick and Dirty Operating System" (a 
placeholder to use during hardware development while waiting for the 
overdue CP/M-86)) .



More details to research, . . .
GWBASIC was a version of BASICA of the 5150/PC, but run from MS-DOS, 
and not requiring the ROMS.  That was so that OEMs of MS-DOS could 
supply BASIC closely matching that of the PC.  Some even renamed 
GWBASIC into "BASICA", topreserve compatability for batch files that 
called BASIC.


Q: What did "GWBASIC" stand for?
at the time, some Microsoft people said that it stood for "Gee Whiz 
BASIC".  But more recently, Microsoft denies any memory of what it 
was, and billg speculated that it stood for "Greg Whitten BASIC".


--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: BASIC

[Mike Katz via cctalk]

The Beginners All-purpose Symbolic Instruction Code (BASIC)

Developed by John G. Kemeny and Thomas E. Kurtz at Dartmouth College in 
1963.  This ran on the Dartmouth Time Sharing System (DTSS) which was an 
early time sharing system running on Honeywell and GE Main Frames with 
Datanet systems running the terminal interfaces.


This system was intended to be an online code/run/debug cycle system 
rather than a batch processing system like most Cobol and Fortran 
compilers were.


BASIC was actually their third language attempt to simplify the syntax 
of languages like Fortran and Algol.


There are literally 100's of dialects of BASIC, both as compilers (as 
was the original) and interpreters and even pseudo compilers.


Like many of us older members of this thread, some form of BASIC was our 
"computer milk language" (our first computer language).


Some early microcomputers even wrote their operating systems in some 
form of BASIC.


I learned basic in September of 1972 on a 4K PDP-8/L running EduSystem 
10 Basic with time also spent at the Kiewit Computation Center at 
Dartmouth (as a 12 year old) running Dartmouth Basic.


Let's hear your earliest introduction to BASIC.





On 5/1/2024 5:03 PM, Murray McCullough via cctalk wrote:

Nostalgia keeps pressing ahead: It was 60 yrs. ago that BASIC came into
existence. I remember very well writing in Apple Basic and GW Basic later
on. As a non-compiled OS, an interpreted OS, it was just the right tool for
a microcomputer with  limited memory. I recall fondly taking code from
popular magazines and getting them to run. It was thrilling indeed!

Happy computing,

Murray 

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

I tried formatting multiple times (standard operating procedure).  I 
don't have a PC with a 3.5" floppy attached any more but I did try bulk 
erasing the disk first.


On 4/30/2024 5:21 PM, Just Kant via cctalk wrote:

Format it more then once. That may afford additional stability.

Try formatting it in a pc. Then switch over to the HP.

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

I am not familiar with a 9114 only the 9114A and 9114B.

On 4/30/2024 6:15 PM, Mike Stein wrote:
Just wondering: I see 9114 and 9114A being used interchangeably (mine 
are 9114s); are they the same or actually different drives?


m


On Tue, Apr 30, 2024 at 5:39 PM Mike Katz via cctalk 
 wrote:


Thank you for your help.

That is the command I am using on the 41 to try and format the disk.
With a directory size of 60.

On 4/30/2024 4:22 PM, Wayne S via cctalk wrote:
> Also this article refers to a set of commands for this drive.
The NEWM command formats a new disk.
> Link is
https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=78
>
>
> Sent from my iPhone
>
> On Apr 30, 2024, at 14:07, Wayne S  wrote:
>
> What kind of floppies did Hp recommend to use with this drive?
>
> Sent from my iPhone
>
> On Apr 30, 2024, at 13:55, Fred Cisin via cctalk
 wrote:
>
> On Tue, 30 Apr 2024, John Herron via cctalk wrote:
> Yup, that's all I used to do. Some scotch tape over the floppy
disk hole to
> make the system see it as DD. If it didn't automatically format
as 720, you
> could specify size or sector count with format.com
<http://format.com> in dos.
>
> Somemedia sensors are optical; use opaque taps.
>
> I did hear folks say it wasn't always reliable (similar to 5.25
disks being
> formated on a high density drive) but I never saw any problems in my
> limited use.
>
> 3.5" are 600 VS 750 oersted;
> 5.25" are 300 vs 600 Oersted;
> a low density 5.25 formatted as "high density" won't do well;
> a high density 5.25" (1.2M) formatted as low density ("360K")
sill self erase VERY soon, sometimes before you can even get it
over to another machine.  We had a college purchasing agent in bed
with "Roytype", who kept giving us "1.2M" floppies ofr out TRS80s;
they self erased very soon.
>
> --
> Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

Yes but hopefully less than $45 for 10 disks.

On 4/30/2024 5:29 PM, Wayne S via cctalk wrote:

Are these the disks you need?

https://www.ebay.com/itm/303254321218?var=0=1=1=711-53200-19255-0=5338590836=10044=bb4f007d293e125433cd664c59b413a4


Sent from my iPhone

On Apr 30, 2024, at 15:22, Just Kant via cctalk  wrote:

Format it more then once. That may afford additional stability.

Try formatting it in a pc. Then switch over to the HP.

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

Thank you.

My goal is not to use HD floppies on a drive not designed for them. I 
saw some on ebay and amazon but I thought I would try here to see if 
anybody had some they don't need.  I would help keep them out of the trash.


Thank you again.

On 4/30/2024 6:15 PM, Wayne S wrote:

If it’s any help, i second the reformat completely a disk in a old pc. I had 
some issues many years ago where disks formatted on an ibm pc didn’t work 
correctly on a non- ibm pc. Reformatting and doing the error checking by 
reading and writing all sections fixed it. A quick format didn’t.
There are lotsa 720k diskette’s available for sale… prices vary. Even Amazon 
has them!

Sent from my iPhone


On Apr 30, 2024, at 15:39, Mike Katz  wrote:

Thank you.  I didn't see any new procedures that I have already tried.

I do not have a problem with the drive or with trying to format a HD disk with 
the HP-41 and therefore I was looking for a few DSDD disks instead of DSHD 
disks.


On 4/30/2024 5:13 PM, Wayne S wrote:
There is also these 2 procedures to try…. From 
https://literature.hpcalc.org/community/hp9114a-ms-en.pdf



TheHP9114Ausesdouble-sideddiscs.Dataiswrittenonboth sides of the disc. Thus the 
normal formatting procedure is double- sided formatting. Single-sided 
formatting is allowed for transferring data from older systems. See the next 
section for single-sided formatting.
Before a flexible disc can be used for the first time, it must be formatted. 
Formatting establishes the directory and volume label as 
wellasverifyingthatthemediaisnotdamaged.Shownnextare two ways to format discs. 
Insert a blank disc into the disc drive.
 From the P.A.M. display, pressing the “File Manager” (f2) softkey gets you to 
a “Format” softkey. Press the key labeled ““Format” (f5) and answer the next 
questions.
“Enter the disc to format”. The first disc drive is assigned the letter C. Type 
C: and press return.
“Enter a volume label (optional).” The volume label is the name you want to 
call the disc. This can be up to 11 characters. For example, let’s call this 
disc “First”. Type First and press Return.

  The information is displayed on the first two lines below the 
cursor.PresstheStartFormatkey(f1)ifthesetwolinesarecorrect.
“Formatting Disc. Please wait.” appears on the display. Formatting a disc takes 
about 1 1/2 minutes. The interleave used with this 
formattingmethodis8,theoptimalforHP Portable/9114A operation.
After formatting is complete, pressing the “’Exit Format” (f8) softkey returns 
you to the main File Manager display. To exit File Manager press the “Exit File 
Manager” softkey. This ends the format procedure.
ThesecondmethodofformattingdiscsistousetheMSDOS Format command. From the 
initial P.A.M. display, tabbing over to the area called “DOS Commands” and 
pressing “Return” allows you to use the DOS command called Format. The 
interleave used inthiscommand is8whichisoptimalforyourHP Portable/9114A system.
Type FORMAT C: and press Return.
“Press any key to begin formatting C:” is displayed. Press any key on the 
keyboard. Formatting takes about 1 1/2 minutes.
After formatting is complete there is another prompt on the display ““Volume 
label (11 characters, Enter for none)?. *“Press “Return”if you don’t want a 
label or enter the name and press “Return” if you want to label the volume.
When completed “Format another (Y/N)?” appears on the display. Typing “N” gets 
you back to entering MS DOS commands. Type “EXIT” to return to P.A.M.
Formatting Single-sided
TheHPPortable/9114Asystemcanformatdouble-sideddiscsina single-sided format. 
This is allowed for data compatability with other 3 1/2-inch disc systems. 
There is a utility called “Format.Com”ontheutilitydiscsuppliedwithyourHP 
Portable computer.Youmustloadthe“Format.Com”utilityintoyourHP Portable. Use the 
following sequence.
PlacetheUtilitydiscintoyourHP9114A. TabovertotheDOS Command 
blockandpressStartApplic.

  From theMS DOS command displaytype: COPY C: FORMAT.COM A: and press Return
This loads the utility and allows you to use the extra parameters 
explainedinthefollowingFORMATcommand.
TheMS DOS command thatallowsthiscompatibilitywithits parameters isshown next.
Format C:/W -Single-sided
/X -Double-sided with 256 byte sectors
/Y -Double-sided with 512 byte sectors /Z -Double-sided with 1024 byte

Sent from my iPhone


On Apr 30, 2024, at 14:39, Mike Katz  wrote:

Thank you for your help.

That is the command I am using on the 41 to try and format the disk.  With a 
directory size of 60.

On 4/30/2024 4:22 PM, Wayne S via cctalk wrote:

Also this article refers to a set of commands for this drive. The NEWM command 
formats a new disk.
Link is https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=78


Sent from my iPhone

On Apr 30, 2024, at 14:07, Wayne S  wrote:

What kind of floppies did Hp recommend to use with this drive?

Sent from my iPhone

On Apr 30, 2024, at 13:55, Fred Cisin via cctalk  wrote:

On Tue, 30 Apr 2024, John Herron via 

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

Thank you.  I didn't see any new procedures that I have already tried.

I do not have a problem with the drive or with trying to format a HD 
disk with the HP-41 and therefore I was looking for a few DSDD disks 
instead of DSHD disks.


On 4/30/2024 5:13 PM, Wayne S wrote:
There is also these 2 procedures to try…. From 
https://literature.hpcalc.org/community/hp9114a-ms-en.pdf




TheHP9114Ausesdouble-sideddiscs.Dataiswrittenonboth sides of the disc. 
Thus the normal formatting procedure is double- sided formatting. 
Single-sided formatting is allowed for transferring data from older 
systems. See the next section for single-sided formatting.
Before a flexible disc can be used for the first time, it must be 
formatted. Formatting establishes the directory and volume label as 
wellasverifyingthatthemediaisnotdamaged.Shownnextare two ways to 
format discs. Insert a blank disc into the disc drive.
From the P.A.M. display, pressing the “File Manager” (f2) softkey gets 
you to a “Format” softkey. Press the key labeled ““Format” (f5) and 
answer the next questions.
“Enter the disc to format”. The first disc drive is assigned the 
letter C. Type C: and press return.
“Enter a volume label (optional).” The volume label is the name you 
want to call the disc. This can be up to 11 characters. For example, 
let’s call this disc “First”. Type First and press Return.


 The information is displayed on the first two lines below the 
cursor.PresstheStartFormatkey(f1)ifthesetwolinesarecorrect.
“Formatting Disc. Please wait.” appears on the display. Formatting a 
disc takes about 1 1/2 minutes. The interleave used with this 
formattingmethodis8,theoptimalforHP Portable/9114A operation.
After formatting is complete, pressing the “’Exit Format” (f8) softkey 
returns you to the main File Manager display. To exit File Manager 
press the “Exit File Manager” softkey. This ends the format procedure.
ThesecondmethodofformattingdiscsistousetheMSDOS Format command. From 
the initial P.A.M. display, tabbing over to the area called “DOS 
Commands” and pressing “Return” allows you to use the DOS command 
called Format. The interleave used inthiscommand 
is8whichisoptimalforyourHP Portable/9114A system.

Type FORMAT C: and press Return.
“Press any key to begin formatting C:” is displayed. Press any key on 
the keyboard. Formatting takes about 1 1/2 minutes.
After formatting is complete there is another prompt on the display 
““Volume label (11 characters, Enter for none)?. *“Press “Return”if 
you don’t want a label or enter the name and press “Return” if you 
want to label the volume.
When completed “Format another (Y/N)?” appears on the display. Typing 
“N” gets you back to entering MS DOS commands. Type “EXIT” to return 
to P.A.M.

Formatting Single-sided
TheHPPortable/9114Asystemcanformatdouble-sideddiscsina single-sided 
format. This is allowed for data compatability with other 3 1/2-inch 
disc systems. There is a utility called 
“Format.Com”ontheutilitydiscsuppliedwithyourHP Portable 
computer.Youmustloadthe“Format.Com”utilityintoyourHP Portable. Use the 
following sequence.
PlacetheUtilitydiscintoyourHP9114A. TabovertotheDOS Command 
blockandpressStartApplic.


 From theMS DOS command displaytype: COPY C: FORMAT.COM A: and press 
Return
This loads the utility and allows you to use the extra parameters 
explainedinthefollowingFORMATcommand.
TheMS DOS command thatallowsthiscompatibilitywithits parameters 
isshown next.

Format C:/W -Single-sided
/X -Double-sided with 256 byte sectors
/Y -Double-sided with 512 byte sectors /Z -Double-sided with 1024 byte

Sent from my iPhone


On Apr 30, 2024, at 14:39, Mike Katz  wrote:

Thank you for your help.

That is the command I am using on the 41 to try and format the disk.  
With a directory size of 60.


On 4/30/2024 4:22 PM, Wayne S via cctalk wrote:
Also this article refers to a set of commands for this drive. The 
NEWM command formats a new disk.
Link is 
https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=78



Sent from my iPhone

On Apr 30, 2024, at 14:07, Wayne S  wrote:

What kind of floppies did Hp recommend to use with this drive?

Sent from my iPhone

On Apr 30, 2024, at 13:55, Fred Cisin via cctalk 
 wrote:


On Tue, 30 Apr 2024, John Herron via cctalk wrote:
Yup, that's all I used to do. Some scotch tape over the floppy disk 
hole to
make the system see it as DD. If it didn't automatically format as 
720, you

could specify size or sector count with format.com in dos.

Somemedia sensors are optical; use opaque taps.

I did hear folks say it wasn't always reliable (similar to 5.25 
disks being

formated on a high density drive) but I never saw any problems in my
limited use.

3.5" are 600 VS 750 oersted;
5.25" are 300 vs 600 Oersted;
a low density 5.25 formatted as "high density" won't do well;
a high density 5.25" (1.2M) formatted as low density ("360K") sill 
self erase VERY soon, sometimes before you can even get it over to 
another machine.  We had a 

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

Thank you for your help.

That is the command I am using on the 41 to try and format the disk.  
With a directory size of 60.


On 4/30/2024 4:22 PM, Wayne S via cctalk wrote:

Also this article refers to a set of commands for this drive. The NEWM command 
formats a new disk.
Link is https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=78


Sent from my iPhone

On Apr 30, 2024, at 14:07, Wayne S  wrote:

What kind of floppies did Hp recommend to use with this drive?

Sent from my iPhone

On Apr 30, 2024, at 13:55, Fred Cisin via cctalk  wrote:

On Tue, 30 Apr 2024, John Herron via cctalk wrote:
Yup, that's all I used to do. Some scotch tape over the floppy disk hole to
make the system see it as DD. If it didn't automatically format as 720, you
could specify size or sector count with format.com in dos.

Somemedia sensors are optical; use opaque taps.

I did hear folks say it wasn't always reliable (similar to 5.25 disks being
formated on a high density drive) but I never saw any problems in my
limited use.

3.5" are 600 VS 750 oersted;
5.25" are 300 vs 600 Oersted;
a low density 5.25 formatted as "high density" won't do well;
a high density 5.25" (1.2M) formatted as low density ("360K") sill self erase VERY soon, sometimes 
before you can even get it over to another machine.  We had a college purchasing agent in bed with 
"Roytype", who kept giving us "1.2M" floppies ofr out TRS80s; they self erased very soon.

--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

Thank you for your help.  This drive is not a normal drive.

Please see my other answers as to why this is the case.

On 4/30/2024 3:49 PM, Fred Cisin via cctalk wrote:

A 720K 3.5" is about 600 Oersted;
a 1.4M 3.5" is about 720-750 Oersted.
You can format a 1.4M as 720K, and often, maybe even usually, get away 
with it; it will be just like a poor quality 720K.

On drives with a media sensor, you can cover the hole during formatting.


On Tue, 30 Apr 2024, Anders Nelson via cctalk wrote:


Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?

=]
--
Anders Nelson
www.andersknelson.com


On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk 


wrote:


Does anybody have any extra 720K (double sided, double density) 3.5"
Floppy Disks that could use a good home?

If so, please email me directly at bit...@12bitsbest.com.

Thank you,

  Mike

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

Thank you for trying to help.  My situation is unusual at best and I'm 
apologize for the extra bandwidth my question is causing.


I am formatting the floppies in an HP-9114A battery operated floppy 
drive connected to an HP-41 calculator over the HP_IL serial interface.


The HP9114A drive uses a modified Sony 3.5" floppy drive running at 600 
RPM instead of the normal 300 RPM.  This is an extremely unusual 
configuration that is different from any PC/MAC/Commodore/Amiga situation.


I have been working with floppies since 1980.  I have written floppy low 
level formatters (WD1771 & WD1791 controllers).  I currently use a 
greaseweasel connected to a pair of 8" drives to create and copy 
floppies for the RX02 on my PDP-8.  I fully understand about density and 
number of tracks, sectors per track, tracks per inch, fm/mfm/gcr 
encoding, etc.


I'm sure if I tried enough 1.44MB floppies I would find a few that might 
work on the HP9114A drive.  However, that was not my question.


I am looking for a dozen or two Double Sided, Double Density 720K 
(formatted capacity) disks to use with this drive.


I appreciate all of the suggestions and help but let's keep the 
bandwidth down and take any floppy compatibility discussions off of the 
group.


Than you again everyone for offering to help,

  Mike

On 4/30/2024 2:41 PM, Wayne S wrote:

What errors are you seeing?


Sent from my iPhone


On Apr 30, 2024, at 12:29, Mike Katz via cctalk  wrote:

I have tried bulk erasing 1.44 MB disks and they still won't format in the 
HP9114A battery operated HP-IL Floppy Disk drive.


On 4/30/2024 12:20 PM, Joshua Rice via cctalk wrote:

On 30/04/2024 18:08, Anders Nelson via cctalk wrote:

Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?

I think it's entirely possible. I'd definitely format them in a 720kb drive 
though to be extra safe. Though original 720KB disks written/formatted  in 
1.44MB drives seem perfectly cromulent from my experience.

However don't quote me on it, The only double density drives i have are super 
early Sony ones built in 1982 and they get pampered with NOS 720kb media (with 
the sliders sellotaped open because no auto opening shutters on my drives!)

Josh Rice

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

I have tried bulk erasing 1.44 MB disks and they still won't format in 
the HP9114A battery operated HP-IL Floppy Disk drive.


On 4/30/2024 12:20 PM, Joshua Rice via cctalk wrote:

On 30/04/2024 18:08, Anders Nelson via cctalk wrote:


Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?


I think it's entirely possible. I'd definitely format them in a 720kb 
drive though to be extra safe. Though original 720KB disks 
written/formatted  in 1.44MB drives seem perfectly cromulent from my 
experience.


However don't quote me on it, The only double density drives i have 
are super early Sony ones built in 1982 and they get pampered with NOS 
720kb media (with the sliders sellotaped open because no auto opening 
shutters on my drives!)


Josh Rice

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

Bulk Erasing is the first thing I tried

On 4/30/2024 12:48 PM, John Robertson via cctalk wrote:

On 2024/04/30 10:08 a.m., Anders Nelson via cctalk wrote:

Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?

=]
--
Anders Nelson
www.andersknelson.com


As I recall you had to bulk erase the old diskette and then you could 
format it as 720 - covering the 1.44 hole of course.


Not bulk erasing (the side of a Weller soldering gun works just fine) 
led to erratic results. We all have Weller guns for fixing computers, eh?


John :-#)#




On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk 


wrote:


Does anybody have any extra 720K (double sided, double density) 3.5"
Floppy Disks that could use a good home?

If so, please email me directly at bit...@12bitsbest.com.

Thank you,

   Mike

[cctalk] Re: Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

No, this is for use in an HJP9114A HP-IL Floppy Drive.


On 4/30/2024 12:08 PM, Anders Nelson via cctalk wrote:

Having grown up with 1.44MB 3.5" floppies, I have a question: is it
possible to use a 1.44MB disk and just format it as a 720K disk?

=]
--
Anders Nelson
www.andersknelson.com


On Tue, Apr 30, 2024 at 1:00 PM Mike Katz via cctalk 
wrote:


Does anybody have any extra 720K (double sided, double density) 3.5"
Floppy Disks that could use a good home?

If so, please email me directly at bit...@12bitsbest.com.

Thank you,

   Mike

[cctalk] Double Density 3.5" Floppy Disks

[Mike Katz via cctalk]

Does anybody have any extra 720K (double sided, double density) 3.5" 
Floppy Disks that could use a good home?


If so, please email me directly at bit...@12bitsbest.com.

Thank you,

 Mike

[cctalk] Re: Z80 vs other microprocessors of the time.

[Mike Katz via cctalk]

I think Ohio Scientific made a computer called the 3B or something like 
that that had a 6502, a Z-80 and a 6800 in it.  If my memory serves.


On 4/23/2024 7:00 PM, Fred Cisin via cctalk wrote:

On Tue, 23 Apr 2024, Van Snyder via cctalk wrote:

I shared an office with a lady who got a computer from Ohio Scientific
that had both a Z80 and a 6502. It also had two 5/25" floppy drives.
She also got a tee-shirt that said "I have two floppies." Except she
didn't.


aside from her floppies, . . .
a significant portion (I remember at one time, somebody at Apple said 
20%)

of Apple users had the Microsoft SoftCard Z80, or imitations thereof.

At least one of the Apple imitations had both 6502 and Z80.

--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Z80 vs other microprocessors of the time.

[Mike Katz via cctalk]

Well, it was beyond the PC's and Sparc stations we had access to at the 
time.


On 4/22/2024 3:28 PM, Christian Kennedy via cctalk wrote:


On 4/22/24 13:12, Fred Cisin via cctalk wrote:

On Mon, 22 Apr 2024, Mike Katz via cctalk wrote:
[Big snip -- hopefully I managed to get attribution right, apologies 
in advance if I borked it]


When I was working for a 6800 C compiler company we could simulate 
all 68000 CPUs before the 68020. The 68020 with it's pipelining and 
branch prediction made it impossible to do cycle accurate timing.


Again, not impossible, but very likely not feasable.


Having done cycle accurate simulation of a pipelined superscalar 
processor, I can assure you it's possible, particularly with hardware 
assist a la Quickturn .


It's also a lot like watching paint dry.

[cctalk] Re: Z80 vs other microprocessors of the time.

[Mike Katz via cctalk]

True, if 1 cycle per second or minute is an acceptable emulation speed.

For that kind of emulation to work the emulator needs to be fed the same 
tasks in the same order and for the same core.  This is even more true 
when the CPU is waiting on internal or external resources.  If you can 
emulate all of the cores, all 3 (or more) levels of cache, all possible 
branch prediction, all possible out of order execution and all possible 
external influences then yes you can emulation anything.  But that would 
be like using one of today's petaflop hyper computers to emulate an ARM 
9 running at the speed of a Z-80 or even slower.


On 4/22/2024 2:57 PM, Paul Koning wrote:



On Apr 22, 2024, at 3:45 PM, Mike Katz  wrote:

Cycle accurate emulation becomes impossible in the following circumstances:
• Branch prediction and pipelining can cause out of order execution and 
the execution path become data dependent. ...

I disagree.  Clearly a logic model will do cycle accurate simulation.  So an 
abstraction of that which still preserves the details of out of order 
execution, data dependency, etc., will also be cycle accurate.

It certainly is true that modern high performance processors with all those 
complexities are hard to simulate, but not impossible.

paul

[cctalk] Re: Z80 vs other microprocessors of the time.

[Mike Katz via cctalk]

Compilers do that with what is called loop rotation optimization.

On 4/22/2024 3:59 PM, Chuck Guzis via cctalk wrote:

On 4/22/24 13:53, Paul Koning via cctalk wrote:

In COMPASS:

MORESA1 A1+B2   (B2 = 2)
SA2 A2+B2
BX6 X1
LX7 X2
SB3 B3-2
SA6 A6+B2
SA7 A7+B2
PL  b3,MORE

My recollection is that putting the stores at the top of the loop and
the loads at the bottom managed to save a few cycles.  Of course, you
have to prime the loop...

--Chuck

[cctalk] Re: Z80 vs other microprocessors of the time.

[Mike Katz via cctalk]

Again, not impossible, but very likely not feasable. 


Well not possible with the hardware available at the time.

If one cycle per minute or less is acceptable then I guess it was possible.

That is why we used in circuit emulators to do cycle accurate counting 
on more complex machines.  This machines were clunky and unreliable but 
they worked for the most part.



On 4/22/2024 3:12 PM, Fred Cisin via cctalk wrote:

On Mon, 22 Apr 2024, Mike Katz via cctalk wrote:
Cycle accurate emulation becomes impossible in the following 
circumstances:

* Branch prediction and pipelining can cause out of order execution
  and the execution path become data dependent.
* Cache memory.  It can be very difficult to predict a cache flush or
  cache miss or cache look aside buffer hit
* Memory management can inject wait states and cause other cycle
  counting issues
* Peripherals can inject unpredictable wait states
* Multi-core processors because you don't necessarily know what core
  is doing what and possibly one core waiting on another core.
* DMA can cause some CPUs to pause because the bus is busy doing DMA
  transfers (not all processors have this as an issue).
* Some CPUs shut down clocks and peripherals if they are not used and
  they take time to re-start.
* Any code that waits for some kind of external input.


Ridiculously impractical, but not impossible.
All of those things could be calculated, and worked around.
Admittedly, we might not have a machine fast enough to do so.
Whereas, emulation that doesn't need to do those can be done with 
systems not extremely faster than the one being emulated.


When I was working for a 6800 C compiler company we could simulate 
all 68000 CPUs before the 68020.  The 68020 with it's pipelining and 
branch prediction made it impossible to do cycle accurate timing.


Again, not impossible, but very likely not feasable.

--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Z80 vs other microprocessors of the time.

[Mike Katz via cctalk]

Once CPUs became faster than memory the faster the memory the faster the 
CPU could run.


That is where CACHE came in.  Expensive small high speed ram chips would 
be able to feed the CPU faster except in case of a cache miss and then 
the cache had to reload from slow memory.  That is why multiple cache 
buffers were implemented so one could be filling (predicatively) while 
another buffer was being used.


Some early CPU's were run slowly enough so that the memory could keep up 
and some had built in hardware handshaking.  For example the 68000 had a 
signal called DTACK which was used by the memory/peripheral to say that 
it had latched the data on the bus (on writes) or that the data is 
stable on the bus (on reads).


Or used quadrature clocks (like the 6809 [the 6809E ran a 2 phase 
non-quadrature clock]) that gave memory more than one cycle time to respond.


On 4/22/2024 3:02 PM, Wayne S via cctalk wrote:

I read somewhere that the cable lengths were expressly engineered to provide 
that signals arrived to chips at nearly the same time so as to reduce chip 
“wait” times and provide more speed.

So that begs a question. Older chips like the Z80 and 8080 lines required other 
support chips that added latency to a system waiting for the support chips to 
“settle”.  Does that imply that newer microprocessors that have support on the 
chip are just generally faster because of that?


Sent from my iPhone


On Apr 22, 2024, at 12:54, Chuck Guzis via cctalk  wrote:

On 4/22/24 12:31, ben via cctalk wrote:

Classic cpu designs like the PDP-1, might be better called RISC.
Back then you matched the cpu word length to data you were using.
40 bits made a lot of sense for real computing, even if you
had no RAM memory at the time, just drum.

I'd call the CDC 6600 a classic RISC design, at least as far as the CPU
went. Classes were given to programming staff on timing code precisely;
I spent many happy hours trying to squeeze the last few cycles out of a
loop (where the biggest bang for the buck was possible).

I think bitsavers (I haven't looked) has a document or two on how to
time code for that thing.

--Chuck

[cctalk] Re: Z80 vs other microprocessors of the time.

[Mike Katz via cctalk]

Cycle accurate emulation becomes impossible in the following circumstances:

 * Branch prediction and pipelining can cause out of order execution
   and the execution path become data dependent.
 * Cache memory.  It can be very difficult to predict a cache flush or
   cache miss or cache look aside buffer hit
 * Memory management can inject wait states and cause other cycle
   counting issues
 * Peripherals can inject unpredictable wait states
 * Multi-core processors because you don't necessarily know what core
   is doing what and possibly one core waiting on another core.
 * DMA can cause some CPUs to pause because the bus is busy doing DMA
   transfers (not all processors have this as an issue).
 * Some CPUs shut down clocks and peripherals if they are not used and
   they take time to re-start.
 * Any code that waits for some kind of external input.

When I was working for a 6800 C compiler company we could simulate all 
68000 CPUs before the 68020.  The 68020 with it's pipelining and branch 
prediction made it impossible to do cycle accurate timing.



On 4/22/2024 1:46 PM, Paul Koning via cctalk wrote:



On Apr 22, 2024, at 2:34 PM, Chuck Guzis via cctalk  
wrote:

On 4/22/24 11:09, Bill Gunshannon via cctalk wrote:


Following along this line of thought but also in regards all our
other small CPUs

Would it not be possible to use something like a Blue Pill to make
a small board (small enough to actually fit in the CPU socket) that
emulated these old CPUs?  Definitely enough horse power just wondered
if there was enough room for the microcode.

Blue pills are so yesterday!  There are far more small-footprint MCUs
out there.   More RAM than any Z80 ever had as well as lots of flash for
the code as well as pipelined 32-bit execution at eye-watering (relative
to the Z80) speeds.

Could it emulate a Z80?  I don't see any insurmountable obstacles to
that.  Could it be cycle- and timing- accurate?   That's a harder one to
predict, but probably.

Probably not.  Cycle accurate simulation is very hard.  It's only rarely been 
done for any CPU, and if done it tends to be incredibly slow.  I remember once 
using a MIPS cycle-accurate simulator (for the SB-1, the core inside the 
SB-1250, later called BCM-12500).  It was needed because the L2 cache flush 
code could not be debugged any other way, but it was very slow indeed.  Almost 
as bad as running the CPU logic model in a Verilog or VHDL simulator.  I don't 
remember the numbers but it probably was only a few thousand instructions per 
second.

Then again, for the notion of a drop-in replacement for the original chip, you 
don't need a cycle accurate simulator, just one with compatible pin signalling. 
 That's not nearly so hard -- though still harder than a SIMH style ISA 
simulation.

paul

[cctalk] Re: Last Buy notification for Z80 (Z84C00 Product line)

[Mike Katz via cctalk]

Even the 6809 could push up to 8 registers (up to 10 bytes) at once on 
one of two stacks in a single two byte instruction.


On 4/21/2024 11:27 AM, Chuck Guzis via cctalk wrote:

On 4/21/24 07:45, Mike Katz via cctalk wrote:


One of the biggest features of the Z-80, the extra register set, was
rarely used in open source software in order to maintain compatibility
with the 8080.

My understanding of the extra (partial) set of registers on the Z80 was
that they were intended for a quick context switch particularly when
processing interrupts--another interesting feature of the Z80 that was
rarely used.  So, for ordinary user code, they were a no-go.  The
alternative on the Intel MPUs was to push each 16-bit register pair at
the entry of the interrupt routine and then pop them at the end; a
relatively slow process, made worse by the requirements for extra stack
space.

Of course, the extra register feature went largely unused, as relatively
few consumer- or hobbyist-level products actually made much use of the
interrupt feature, much less, the 256-level vectored interrupt facility.

The 8086 continued this trend of requiring explicit saves; some of the
NEC V-series chips (e.g. V25), however, did implement extra register
sets (8 total, IIRC) for fast context switches.

--Chuck

[cctalk] Re: Last Buy notification for Z80 (Z84C00 Product line)

[Mike Katz via cctalk]

Well my PDP-8 was built in 1974 and is still running (with careful 
maintenance).  My PiDP-8/I has been up and running continuously with a 
Raspberry PI 3B running it for about 5 years now.  My PiDP-11 has been 
up and running with a PI-4B for more than 4 years continuously.


Though I agree with your comment that the PDP-8 was built to last (just 
ignore the disintegrated foam used between the motherboard and the case 
or on the case top) I have PCs that are more than 10 years old that are 
still running.


As for the RP2040 being cheap crap, I beg to differ with you.  It is a 
solid chip, produced in 10s of millions at least.  And, I would bet, a 
better quality chip than your Z-80, if due only to improved IC 
manufacturing technologies.


Just because it's old doesn't make it good.  I worked on a 32KHz 4 Bit 
CPU (about 20 years ago) where the development hardware was very 
unstable and the tool chain not a whole lot better.


Early Microsoft and Lattice C compilers for the PC were buggy as hell.  
If you want I can list a few bugs from each of them in another thread.


One of the biggest features of the Z-80, the extra register set, was 
rarely used in open source software in order to maintain compatibility 
with the 8080.


Some of the early Z-80 CP/M tools did not work because they were derived 
from 8080 tools.  After time the tools got better.  That is the case 
with any piece of software.  If it doesn't become obsolete and if 
maintained it will get better over time.




On 4/21/2024 1:09 AM, ben via cctalk wrote:

On 2024-04-20 8:33 p.m., Mike Katz via cctalk wrote:
For anything more sophisticated than your coffee pot the RP2040 from 
Raspberry Pie is a fantastic little chip, dual core 133 MHz Cortex 
M0+ with 8 PIO engines, 264K of RAM, ADC, UART, SPI, I2C all for 
under a dollar.  I designed a fully functional RP2040 with 16 Mb 
flash for under $2.00.  In large enough quantities that's encroaching 
on 8 bit PIC territory at over 1000 times the memory and CPU power.


I am wishing for a Quality Product, cheap crap is not always better.
USB comes to mind.
256Kb ram is only 32K 64 bit words. Cache memory never works.
My $5 internet toaster, just exploded after 3 days.
So what? Just buy the new model that works with windows 12.
Download a buggy new tool chain. The Z80 tools worked.


The PDP8 was built to last. 50+ years and going strong.
NOT the crappy PI PDP-8 or PDP-10. I give it 2 years max.
Now a PI style computer with compact FLASH x 2, NO USB
and 2 MEG ram , real serial and printer ports that will work
in a noisy industrial setting, would be quite usefull.
I'd pay even $3 for it. :)

[cctalk] Re: Last Buy notification for Z80 (Z84C00 Product line)

[Mike Katz via cctalk]

For anything more sophisticated than your coffee pot the RP2040 from 
Raspberry Pie is a fantastic little chip, dual core 133 MHz Cortex M0+ 
with 8 PIO engines, 264K of RAM, ADC, UART, SPI, I2C all for under a 
dollar.  I designed a fully functional RP2040 with 16 Mb flash for under 
$2.00.  In large enough quantities that's encroaching on 8 bit PIC 
territory at over 1000 times the memory and CPU power.


On 4/20/2024 6:30 PM, Doc Shipley via cctalk wrote:

On 4/20/24 13:16, Wayne S via cctalk wrote:
Who still uses the Z80 line for new projects? Wouldn’t it be easier 
and cheaper to just use an Arduino or Raspberry Pi?


I dissected a dead coffee maker last week that has a current-design 
8051 clone running the control board.


Well-known instruction sets and "Nobody cares if I clone this" make 
powerful arguments



Doc

[cctalk] Re: Drum memory on pdp11's? Wikipedia thinks so....

[Mike Katz via cctalk]

There was drum storage for the early PDP-8 the "Straight 8", PDP-9 and 
PDP-10.  Each drum stored 32,768 words.  Up to 8 of them could be 
connected for a total storage of 262,144 words of storage.


IBM made a 5BM drum storage unit that was the side of a small 
refrigerator: The RAMAC's disk storage unit, the IBM 350, weighed over a 
ton, had to be moved around with forklifts, and was delivered via large 
cargo airplanes. It stored approximately 5MB of data: *five million 
8-bit characters on fifty 24-inch-diameter disks*, a form of drum memory.


On 4/15/2024 11:06 AM, Douglas Taylor via cctalk wrote:
At the VFC East just a few days ago a young man came up to me, I had a 
PDP11/53 on display, and showed me pictures of his 11/45 and PDP-8 
that he had just acquired and needed to learn about.  It was 
impressive, he said the 11/45 was missing the memory boards.  If he 
shows up here on the list please help him.  To me, it look like he had 
stumbled into a Unicorn.

Doug

On 4/13/2024 5:26 PM, Christopher Zach via cctalk wrote:

Was reading the Wikipedia article on Drum memories:

https://en.wikipedia.org/wiki/Drum_memory#External_links

And came across this tidbit.

 As late as 1980, PDP-11/45 machines using magnetic core main memory 
and drums for swapping were still in use at many of the original UNIX 
sites.


Any thoughts on what they are talking about? I could see running the 
RS03/RS04 on a 11/45 with the dual Unibus configured so the RS03's 
talk to memory directly instead of the Unibus, but that's not quite 
the same as true drum memory.


Closest thing I remember was the DF32 on a pdp8 which could be 
addressed by word as opposed to track/sector.


Thoughts?
C

[cctalk] Re: IBM 360

[Mike Katz via cctalk]

I want to thank you all for this IBM 360 conversation.  It makes me feel 
young.  My first computer was a PDP-8/L with 4K of core memory and a 
Teletype ASR-33.  That was 1972 (I was 12).


On 4/10/2024 4:23 PM, Paul Koning via cctalk wrote:



On Apr 10, 2024, at 5:01 PM, Van Snyder via cctalk  
wrote:

...
I think the 360/67 replaced "Halt and Catch Fire" with "Rewind and
Break Tape."

I always wondered if that wasn't a standard property of IBM tape drives of that 
era.  The ones I remember from our 360/44 had capstans that turned 
continuously, one to each side of the head.  The tape was shoved against the 
capstan to start tape motion, and against a rubber brake block to stop it.  
That was wild enough, but the other crazy aspect is that the vacuum columns 
were arranged so the oxide was facing outward, i.e., rubbing against the side 
walls of the vacuum column.

I never did wear out a tape, but then again, I never used a tape more than a 
half dozen times on that system.

paul

[cctalk] Re: oscilloscopes

[Mike Katz via cctalk]

For some reason the mailing list deleted the link to the photo, I'm sorry.

On 4/3/2024 11:01 AM, Mike Katz via cctalk wrote:
I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A 
mainframe scope.


The 475A is rock solid and is one of the best analog triggering scopes 
ever made.  The 11403A goes all the way up to 3GHz but, tbh, is was a 
difficult to use touch screen scope.  I still use both of them 
occasionally.


I had a Sony Tektronix Battery Operated 10 or 20 MHz scope ( I can't 
remember which) that was lent out never to be seen again. The nicest 
thing about it was that the two channels were completely electrically 
isolated from each other.


My go to scopes now are a couple of PicoScope USB scopes with logic 
analyzers and arbitrary function generators.


Here are the two TEK scopes.  The 475A is showing both a sine and a 
square wave at 1 MHz (chopped).  The 11403A is showing a 1GHz sine 
wave and 7 other unconnected traces just to show that is can display 8 
traces at once.  The three plugins on the 11403A are, 4 trace 
3000MHz/trace, 2 trace 1GHz/trace and 2 trace 50MHz Current Probe 
Amplifier.




On 4/1/2024 5:56 PM, Fred Cisin via cctalk wrote:

On Mon, 1 Apr 2024, Just Kant via cctalk wrote:
I have more then I need. All the working ones are HP w/color crts, 
and as far as older, verifiably vintage tools (right down to the 
680x0 processor in either) I have to admit I favor them as a brand. 
Call we an oddball, weird egg, badges I wear with pride.
But who could resist the allure of the newer ultra portable, even 
handheld units (some with bandwidth or sampling rates to 50mhz). I'm 
a big cheapo. But there's no real reason to agonize over a 65 - 200$ 
or thereabouts acquisition. It's a bit tiring to wade through the 
piles of availability. I favor a desktop unit, larger screen (but 
not always, careful). But most of those need wall current I think? 
The convenience of a handheld battery powered unit obviously has 
it's benefits.
I will always love and dote upon my color crt based HPs. But the 
damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d 
over, hit the paved floor, shook the house. And still works! Built 
to withstand an atomic bombardment.


I had a Tektronix 512,
and an NLS215 (battery powered portable) from a company that switched 
over to making Kaypros.  I gave it away at one of the first VCFs.

I guess that the vintage ones are no longer adequate.

--
Grumpy Ol' Fred

[cctalk] Re: oscilloscopes

[Mike Katz via cctalk]

I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A 
mainframe scope.


The 475A is rock solid and is one of the best analog triggering scopes 
ever made.  The 11403A goes all the way up to 3GHz but, tbh, is was a 
difficult to use touch screen scope.  I still use both of them occasionally.


I had a Sony Tektronix Battery Operated 10 or 20 MHz scope ( I can't 
remember which) that was lent out never to be seen again.  The nicest 
thing about it was that the two channels were completely electrically 
isolated from each other.


My go to scopes now are a couple of PicoScope USB scopes with logic 
analyzers and arbitrary function generators.


Here are the two TEK scopes.  The 475A is showing both a sine and a 
square wave at 1 MHz (chopped).  The 11403A is showing a 1GHz sine wave 
and 7 other unconnected traces just to show that is can display 8 traces 
at once.  The three plugins on the 11403A are, 4 trace 300MHz/trace, 2 
trace 1GHz/trace and 2 trace 50MHz Current Probe Amplifier.


https://drive.google.com/file/d/10lFayScEaebLSAKRyEhUmIC_MoONMkcu/view?usp=sharing

On 4/1/2024 5:56 PM, Fred Cisin via cctalk wrote:

On Mon, 1 Apr 2024, Just Kant via cctalk wrote:
I have more then I need. All the working ones are HP w/color crts, 
and as far as older, verifiably vintage tools (right down to the 
680x0 processor in either) I have to admit I favor them as a brand. 
Call we an oddball, weird egg, badges I wear with pride.
But who could resist the allure of the newer ultra portable, even 
handheld units (some with bandwidth or sampling rates to 50mhz). I'm 
a big cheapo. But there's no real reason to agonize over a 65 - 200$ 
or thereabouts acquisition. It's a bit tiring to wade through the 
piles of availability. I favor a desktop unit, larger screen (but not 
always, careful). But most of those need wall current I think? The 
convenience of a handheld battery powered unit obviously has it's 
benefits.
I will always love and dote upon my color crt based HPs. But the 
damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d 
over, hit the paved floor, shook the house. And still works! Built to 
withstand an atomic bombardment.


I had a Tektronix 512,
and an NLS215 (battery powered portable) from a company that switched 
over to making Kaypros.  I gave it away at one of the first VCFs.

I guess that the vintage ones are no longer adequate.

--
Grumpy Ol' Fred

[cctalk] Re: oscilloscopes

[Mike Katz via cctalk]

I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A 
mainframe scope.


The 475A is rock solid and is one of the best analog triggering scopes 
ever made.  The 11403A goes all the way up to 3GHz but, tbh, is was a 
difficult to use touch screen scope.  I still use both of them occasionally.


I had a Sony Tektronix Battery Operated 10 or 20 MHz scope ( I can't 
remember which) that was lent out never to be seen again.  The nicest 
thing about it was that the two channels were completely electrically 
isolated from each other.


My go to scopes now are a couple of PicoScope USB scopes with logic 
analyzers and arbitrary function generators.


Here are the two TEK scopes.  The 475A is showing both a sine and a 
square wave at 1 MHz (chopped).  The 11403A is showing a 1GHz sine wave 
and 7 other unconnected traces just to show that is can display 8 traces 
at once.  The three plugins on the 11403A are, 4 trace 3000MHz/trace, 2 
trace 1GHz/trace and 2 trace 50MHz Current Probe Amplifier.




On 4/1/2024 5:56 PM, Fred Cisin via cctalk wrote:

On Mon, 1 Apr 2024, Just Kant via cctalk wrote:
I have more then I need. All the working ones are HP w/color crts, 
and as far as older, verifiably vintage tools (right down to the 
680x0 processor in either) I have to admit I favor them as a brand. 
Call we an oddball, weird egg, badges I wear with pride.
But who could resist the allure of the newer ultra portable, even 
handheld units (some with bandwidth or sampling rates to 50mhz). I'm 
a big cheapo. But there's no real reason to agonize over a 65 - 200$ 
or thereabouts acquisition. It's a bit tiring to wade through the 
piles of availability. I favor a desktop unit, larger screen (but not 
always, careful). But most of those need wall current I think? The 
convenience of a handheld battery powered unit obviously has it's 
benefits.
I will always love and dote upon my color crt based HPs. But the 
damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d 
over, hit the paved floor, shook the house. And still works! Built to 
withstand an atomic bombardment.


I had a Tektronix 512,
and an NLS215 (battery powered portable) from a company that switched 
over to making Kaypros.  I gave it away at one of the first VCFs.

I guess that the vintage ones are no longer adequate.

--
Grumpy Ol' Fred

[cctalk] Re: oscilloscopes

[Mike Katz via cctalk]

I'm surprised some digital scope manufacturer hasn't implemented X-Y-Z 
control as an option.   Driving X-Y was fairly common for certain types 
of signals.  And many also used the Z input.


Back in the day there were many companies that made X-Y or X-Y-Z displays.

On 4/3/2024 10:01 AM, Guy Fedorkow via cctalk wrote:
Vintage computer enthusiasts might want to keep track of where to find 
CRT-based analog oscilloscopes, for use as output devices.
The early MIT and Lincoln Labs computers used D/A converters to steer 
and activate the beam on analog scopes to draw vector images.
Working on Whirlwind simulation, we've been able to get this technique 
to work with "real" oscilloscopes, e.g., Tek 475, but we have not yet 
found a single DSO that has X/Y _and_ Z inputs (let alone the required 
phosphor fade).


  Myself, I have a couple scopes with backups, so I'm not in the 
market for another one.  But others might consider the option...


  /guy fedorkow


Date: Mon, 01 Apr 2024 22:33:38 +
From: Just Kant
Subject: [cctalk] oscilloscopes
To: "General Discussion: On-Topic and Off-Topic Posts"

Message-ID: 
Content-Type: text/plain; charset=utf-8

I have more then I need. All the working ones are HP w/color crts, and 
as far as older, verifiably vintage tools (right down to the 680x0 
processor in either) I have to admit I favor them as a brand. Call we 
an oddball, weird egg, badges I wear with pride.


But who could resist the allure of the newer ultra portable, even 
handheld units (some with bandwidth or sampling rates to 50mhz). I'm a 
big cheapo. But there's no real reason to agonize over a 65 - 200$ or 
thereabouts acquisition. It's a bit tiring to wade through the piles 
of availability. I favor a desktop unit, larger screen (but not 
always, careful). But most of those need wall current I think? The 
convenience of a handheld battery powered unit obviously has it's 
benefits.


I will always love and dote upon my color crt based HPs. But the 
damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d 
over, hit the paved floor, shook the house. And still works! Built to 
withstand an atomic bombardment.

[cctalk] Re: oscilloscopes

[Mike Katz via cctalk]

I still have a TEK 475A (with the DMM4 on top) and a TEK 11043A 
mainframe scope.


The 475A is rock solid and is one of the best analog triggering scopes 
ever made.  The 11403A goes all the way up to 3GHz but, tbh, is was a 
difficult to use touch screen scope.  I still use both of them occasionally.


I had a Sony Tektronix Battery Operated 10 or 20 MHz scope ( I can't 
remember which) that was lent out never to be seen again.  The nicest 
thing about it was that the two channels were completely electrically 
isolated from each other.


My go to scopes now are a couple of PicoScope USB scopes with logic 
analyzers and arbitrary function generators.


Here are the two TEK scopes.  The 475A is showing both a sine and a 
square wave at 1 MHz (chopped).  The 11403A is showing a 1GHz sine wave 
and 7 other unconnected traces just to show that is can display 8 traces 
at once.  The three plugins on the 11403A are, 4 trace 3000MHz/trace, 2 
trace 1GHz/trace and 2 trace 50MHz Current Probe Amplifier.




On 4/1/2024 5:56 PM, Fred Cisin via cctalk wrote:

On Mon, 1 Apr 2024, Just Kant via cctalk wrote:
I have more then I need. All the working ones are HP w/color crts, 
and as far as older, verifiably vintage tools (right down to the 
680x0 processor in either) I have to admit I favor them as a brand. 
Call we an oddball, weird egg, badges I wear with pride.
But who could resist the allure of the newer ultra portable, even 
handheld units (some with bandwidth or sampling rates to 50mhz). I'm 
a big cheapo. But there's no real reason to agonize over a 65 - 200$ 
or thereabouts acquisition. It's a bit tiring to wade through the 
piles of availability. I favor a desktop unit, larger screen (but not 
always, careful). But most of those need wall current I think? The 
convenience of a handheld battery powered unit obviously has it's 
benefits.
I will always love and dote upon my color crt based HPs. But the 
damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d 
over, hit the paved floor, shook the house. And still works! Built to 
withstand an atomic bombardment.


I had a Tektronix 512,
and an NLS215 (battery powered portable) from a company that switched 
over to making Kaypros.  I gave it away at one of the first VCFs.

I guess that the vintage ones are no longer adequate.

--
Grumpy Ol' Fred

[cctalk] Re: Cleanup time again

[Mike Katz via cctalk]

Considering how high some prices are on eBay.  I would rather something 
go to a good home at a lower price than help drive the prices up on ePay.


On 3/21/2024 4:01 PM, Sellam Abraham via cctalk wrote:

On Thu, Mar 21, 2024 at 12:33 PM CAREY SCHUG via cctalk <
cctalk@classiccmp.org> wrote:


--does anybody want to comment on whether ebay prices are less, similar,
or greater than at live VCFs?  I have not made the effort to collect
history.


It depends, usually less.  Sometimes the same or more.

Sellam

[cctalk] Re: 5 1/4" and 3.5" disk duplication machines

[Mike Katz via cctalk]

If I were to build a diskette copier today I would us some kind of 
magnetic flux reader/writer (like the greaseweazle).


That way it is format agnostic.   It can copy almost any disk that can 
be read.


I have a script for my greaseweazle that will copy any 8" diskette (mine 
is setup for 8" RX02 diskettes).  Granted, it copies by saving the image 
to disk and then writing it back out.  This allows the use of either 1 
single disk system or the ability to make multiple copies without having 
to re-read the source diskette.


On 3/10/2024 1:01 PM, John Herron via cctalk wrote:

If referring to commercial systems, I imagine that and discussion on
copyright techniques might be interesting to a hardcore crowd. If just
archiving, I also think that would be useful to the public.

I only saw cd/dvd based systems and harddisk duplicators. Newer stuff
though, not what I would consider vintage.

On Sat, Mar 9, 2024, 3:55 PM Bill Degnan via cctalk 
wrote:


Does anyone have interest in vintage diskette duplication / duplication
machines? Would this make for an interesting VCF exhibit?  Does/did anyone
use these commercially?
  Bill

[cctalk] Re: vt220 firmware source?

[Mike Katz via cctalk]

you may already know about these but here are a few 8051 Simulators:

https://www.electronicshub.org/8051-simulators/

And thoughts on using MAME to emulate terminals:

https://zork.net/~st/jottings/Real-VT102-emulation-with-MAME.html

Good luck.  I have a fully functional VT-330+ and a fully functional 
VT-220 if i can help at all.



On 2/5/2024 10:23 AM, Paul Flo Williams via cctalk wrote:

On Sun, 04 Feb 2024 16:26:57 -0700
Richard via cctalk  wrote:


In article  you
write:

I'm about to dive in to commenting the disassembly listings, but
figured I'd ping here to see if anybody might have done this already
in case I wouldn't have to start from scratch?

Give IDA Pro or Ghidra a crack at it to help you make sense of the raw
disassembly.

I made pretty good progress on VT100 ROMs before Paul Williams put up
a completely reverse engineered commented listing.

Well, in case it helps, I'll explicitly disclaim any intention of
disassembling the VT220 :-)

After the VT100, I did make a start on the VT102/131 combination but it
seemed too samey to hold my interest.

More than 20 years ago, I started on the VT320, as my personal
favourite, but I didn't understand how to tackle emulation at the
time, the 8051 emulator I wrote had flaws, and I spent a long time on
getting the emulated video timing correct enough to even pass self
test! If only the VT320 had had a technical reference as comprehensive
as that published for the VT100. I will return to it at some point,
probably using some else's 8051 core, as Peter Sichel (last head of
DEC's terminals group) bet me that I wouldn't be able to do it.

At the moment, I'm tackling another full commentary, but it may well
have an even smaller audience than that for the VT100; I'm 83% through
gutting the arcade game Star Force. I've even fixed two æsthetic bugs
in the game, 40 years too late for anyone to care. At least this is Z80
assembler, and tinkering with that has always made me *very* happy.

Paul.

[cctalk] Re: Qume 842 8" Disk Drive Question

[Mike Katz via cctalk]

I haven't worked on 8" drives since the early 80's with th exception of 
the RX02 drives on my PDP-8.


And DEC worked their own "magic" on those drives :)

Thanks for the help.

On 1/31/2024 3:59 PM, Chuck Guzis via cctalk wrote:

On 1/31/24 13:03, Mike Katz via cctalk wrote:

Michael,

Thank you, that was what I was planning as my next step.  I haven't
checked to see if the service manual has a full schematic.

The main purpose of my message on here was to see if I was missing
something obvious like an option trace cut or something like that that I
missed when I checked the manual.

Thanks again,

Mike -

There is indeed a schematic in the 842 service manual PDF page 87 is
what you're looking for.  Since the LEDs are always powered, you need
only be concerned with the output of the phototransistor.  DMM is fine;
no scope necessary.   An opto going bad is not completely unknown on
these drives.  (I have a couple of the 842s--good drives, otherwise)

Diskette drives really are non-intelligent devices...

--Chuck

[cctalk] Re: Qume 842 8" Disk Drive Question

[Mike Katz via cctalk]

I believe the pull ups are all on inputs from the external controller 
and not for outputs from the drive itself.  Looking at the schematic the 
Index output (J1-P20) does not go through the pull up resistors.


Thanks again for your help.

On 1/31/2024 3:59 PM, Chuck Guzis via cctalk wrote:

On 1/31/24 13:03, Mike Katz via cctalk wrote:

Michael,

Thank you, that was what I was planning as my next step.  I haven't
checked to see if the service manual has a full schematic.

The main purpose of my message on here was to see if I was missing
something obvious like an option trace cut or something like that that I
missed when I checked the manual.

Thanks again,

Mike -

There is indeed a schematic in the 842 service manual PDF page 87 is
what you're looking for.  Since the LEDs are always powered, you need
only be concerned with the output of the phototransistor.  DMM is fine;
no scope necessary.   An opto going bad is not completely unknown on
these drives.  (I have a couple of the 842s--good drives, otherwise)

Diskette drives really are non-intelligent devices...

--Chuck

[cctalk] Re: Qume 842 8" Disk Drive Question

[Mike Katz via cctalk]

That is one of the tests recommended in the service manual.  It's on my 
list of things to check.


Thank you...

On 1/31/2024 2:17 PM, Chuck Guzis via cctalk wrote:

On 1/31/24 11:12, Mike Katz via cctalk wrote:

I have not yet tried installing terminating resistors...

That might help.  It's also possible that the LED/phototransistor for
the SS index position is faulty.  The two LEDs (SS and DS) are connected
in series, so you know that at least one isn't open.  Grab your DMM and
check the voltage levels on pins A6 and A7 on connector J2.  They should
change as the beam is broken in each with a piece of tinfoil or
something else opaque.

--Chuck

[cctalk] Re: Qume 842 8" Disk Drive Question

[Mike Katz via cctalk]

Michael,

Thank you, that was what I was planning as my next step.  I haven't 
checked to see if the service manual has a full schematic.


The main purpose of my message on here was to see if I was missing 
something obvious like an option trace cut or something like that that I 
missed when I checked the manual.


Thanks again,

 Mike

On 1/31/2024 2:29 PM, Michael Thompson wrote:
Connect an oscilloscope to the output of the single-sided sensor and 
see if it works. If so, trace the signal through the logic and see if 
it gets to the I/O connector that goes to the greaseweazel.


On Wed, Jan 31, 2024 at 2:38 PM Mike Katz via cctalk 
 wrote:


I have recently acquired a Qume Model 842 double sided 8" disk drive.

I have reset all of the settings to factory default and hooked it
up to
my greastweazle.

The drive works perfectly for double sided disks (using the
appropriate
index hole).

However, the greaseweasel reports no index pulse when I put a single
sided diskette in the drive.  I have attempted to clean out the
sensor
for single sided diskettes to on avail.

Does any one have any ideas?

The grease weasel works perfectly when I connect SA-800 drives.

I have not yet tried installing terminating resistors in the Qume.

Thank you in advance for your help,

   Mike

[cctalk] Qume 842 8" Disk Drive Question

[Mike Katz via cctalk]

I have recently acquired a Qume Model 842 double sided 8" disk drive.

I have reset all of the settings to factory default and hooked it up to 
my greastweazle.


The drive works perfectly for double sided disks (using the appropriate 
index hole).


However, the greaseweasel reports no index pulse when I put a single 
sided diskette in the drive.  I have attempted to clean out the sensor 
for single sided diskettes to on avail.


Does any one have any ideas?

The grease weasel works perfectly when I connect SA-800 drives.

I have not yet tried installing terminating resistors in the Qume.

Thank you in advance for your help,

  Mike

On 1/31/2024 12:56 PM, Martin Bishop via cctalk wrote:

Ah, PPC VME cards, add VXworks, funky coprocessors, COTS IO and you have 
definitely got something best avoided : details would involve libations.

The conduction cooled chassis are OK and worth repurposing.  Contrariwise the 
VME bus is best avoided, whether classic 32b VME or the 64 bit revision.  
However, the connectors for VME 64x backplanes and the form factor have merit, 
but that is to depart from the past.

Martin

-Original Message-
From: Wouter de Waal via cctalk [mailto:cctalk@classiccmp.org]
Sent: 31 January 2024 18:34
To: cctalk@classiccmp.org
Cc: Wouter de Waal 
Subject: [cctalk] Re: Vmebus



Anyone have a VMEbus system they use at least occasionally? If so, what
make/model/config?

I still use a couple of PPC VME boards (DY4 / Curtiss Wright 182/183/184, both 
Conduction-Cooled and Air-Cooled) to test the tail end of hardware that we are 
still shipping (by now EOL and basically NOS).

But it's work, I don't find them interesting.

If someone here has the warm fuzzies for PPC VME, we can talk :-)

W

[cctalk] Re: PDP-8/E front panels

[Mike Katz via cctalk]

I have tired to print the paddle handles both SLA and FDM and none match 
the quality and strength of injected molded paddles.


Unless you print an entire set (light and dark colors) it is nearly 
impossible to match the colors also.  Even if you were to find the 
perfect filament or resin color, the variability between batches makes 
accurate reproduction nearly impossible.




On 11/17/2023 10:15 AM, Tom Hunter via cctalk wrote:

I had some toggles printed for me professionally, but they are inferior to
the originals and the colours don't match.

If anyone has spare DEC LAB-8/e switches please let me know.

Thanks
Tom

On Fri, Nov 17, 2023, 10:14 PM Bill Gunshannon via cctalk <
cctalk@classiccmp.org> wrote:



On 11/17/2023 8:52 AM, Tom Hunter via cctalk wrote:

Hi Bob,
I can't help with your search for 8/e front panels, but you mentioned
"green switch boards". I have a nicely restored DEC LAB-8/e with green
switch toggles. Do you have spare green switch toggles? I would love to
have one dark green and one light green toggle. I don't need the actual
switch, but would be happy to take the toggles with switch. Please let me
know if you can help.


Have you ever considered making your own?

https://www.thingiverse.com/thing:360853


bill

[cctalk] Re: What happened to the PDP-8 on ebay?

[Mike Katz via cctalk]

The original listing price was $25,000 and was reduced to $18,000 when 
there we no bids at the original price.


On 10/5/2023 2:34 PM, Sellam Abraham via cctalk wrote:

On Tue, Oct 3, 2023, 9:18 PM jim stephens via cctalk 
wrote:



On 10/3/23 21:23, Bill Degnan via cctalk wrote:

There was a PDP-8 (rack straight 8 with asr33) that was on ebay that
disappeared..anyone know if it was sold?  I can't find it, maybe the

seller

pulled the auction to sell privately.
Bill

I trolled thru VCF forum and I think this is the one you recall. It's
the last straight 8 I saw listed.

https://www.ebay.com/itm/145314563635

I also off your topic have observed a German listing and British listing
for Olivetti Programma 101s for 40,000 pounds and 60,000 euro, in the
same fantasy range as this listing which is for $18,000.

This listing shows currently terminated September 20 due to an error in
the listing.  No relist by this vendor.  He also did something on Sept 2
with is.

Thanks
jim


Realistically, $18,000 is not a bad price at all for a complete PDP-8. The
only downside is the broken off corner of the front panel glass.

Sellam

[cctalk] Teletypes for sale - redux with pics on google drive and contact info.

[Mike Katz via cctalk]

Hey folks. I need to re-home a bunch of cool old Teletype Corporation
machines. Working condition unknown, and also have some spare parts. I
am not out to make a mint, so make offer! They seem mostly complete, in
varying condition. Some are nicer than others. They all worked when
stored (years ago) The following need to find new homes:
TT Model 28 ASR (3 of these)
TT Model 28 KSR (2 of these)
TT Model 28 RO (2 of these)
Extra Model 28 Parts
TT Model 28 Floor Standing Paper Punch
TT Model 32 Baudot
TT Model 35 KSR (heavy duty version of the ASR-33)
TT Model 35 ASR (Floor stand heavy duty, 2 of these, one Telex)
TT Model 40 Dataspeed
Teletype manuals and documentation for each model
Tell your friends! Delivery is possible. I can assist with loading.
Message me for details. Located in the Midwest (Missouri)

Pictures: 
https://drive.google.com/drive/folders/1iWKntZTwws1Qdk6JPEh4f7BjbP0of62t?usp=sharing


Contact:

Mat at Mobile Techinical Services, (217) 690-9239 (mobiletechs...@gmail.com)

[cctalk] Teletypes for sale

[Mike Katz via cctalk]

Hey folks. I need to re-home a bunch of cool old Teletype Corporation 
machines. Working condition unknown, and also have some spare parts. I 
am not out to make a mint, so make offer! They seem mostly complete, in 
varying condition. Some are nicer than others. They all worked when 
stored (years ago) The following need to find new homes:

TT Model 28 ASR (3 of these)
TT Model 28 KSR (2 of these)
TT Model 28 RO (2 of these)
Extra Model 28 Parts
TT Model 28 Floor Standing Paper Punch
TT Model 32 Baudot
TT Model 35 KSR (heavy duty version of the ASR-33)
TT Model 35 ASR (Floor stand heavy duty, 2 of these, one Telex)
TT Model 40 Dataspeed
Teletype manuals and documentation for each model
Tell your friends! Delivery is possible. I can assist with loading. 
Message me for details. Located in the Midwest (Missouri)


https://www.facebook.com/groups/vintagecomputerclub/permalink/7307144265985543/

[cctalk] Re: Good C to FPGA/PLA compiler

[Mike Katz via cctalk]

Martin,

Thank you for all of your suggestions.

I am a software guy who has dabbled in hardware since I built my first 
Heathkit in 1972.  I have designed simple 6809 single boards in my past 
professional life but the Omnibus is several orders of magnitude more 
complicated than a 6809.


Just reading the Single Cycle Data Break documentation in the Omnibus 
spec is enough to give me a headache.


I think in C much better than I think in logic gates.  I can write 
parallel C to describe parallel circuits.  The last time I programmed 
any programmable logic it was FPGA's of the 10L8/16V10 variety.


Sometimes the data is on the memory bus, sometimes it is on the data 
bus, depending on whether you are reading or writing to memory, for example.


There is no bus multplexing between address and data or data and memory 
busses.


Here is the basic definition of the Omnibus:

Memory Address:     15 Signals
Memory Data:               12 Signals
Memory Direction:      1 Signal
Data Bus:                        12 Signals
I/O Control Signals:       10 Signals
DMA Control Signals:  8 Signals
Timing Signals:         9 Signals
CPU State:                     6 Signals
Memory Timing:              5 Signals
Misc Signals:                   18 Signals (Mostly used by the front panel)

One of my goals here is to use thru hole parts and sockets so the 
average person can assemble it.  I realize this may be impossible bit 
I'm trying.


I have a good surface mount contract manufacturer close to my home that 
I have a business relationship will so I can go to full surface mount if 
I have to but that will increase the cost of the boards.



On 9/22/2023 6:53 PM, Martin Bishop via cctalk wrote:

Mike

An M0 will require an FPGA below it to interact with the OmniBus

A BeagleBone, using the PRUs - which are ~microcoded, would be in with more of 
a chance

Industrial grade SoCs / FPGAs should have no difficulty

Martin

-Original Message-
From: Mike Katz via cctalk [mailto:cctalk@classiccmp.org]
Sent: 23 September 2023 00:27
To: General Discussion: On-Topic and Off-Topic Posts 
Cc: Mike Katz 
Subject: [cctalk] Re: Good C to FPGA/PLA compiler

I plan on controlling the gate array with an RP2040 dual core cortex M0 running 
at 133 MHz and 8 PIO processors.

However, the Data Break (DMA) timings on the Omnibus are in the 100nS range.  
The bus runs 6 different timing signals plus manipulating all of the other 
signals to implement Data Break. I just don't think a micro would be fast 
enough.

That same holds for the break point.  In order to be able to respond to address, 
data, r/w and count for 4 breakpoints in the <1uS window to stop the CPU before 
the start of the next cycle would stress most embedded micros (sub  $10 micros 
anyway).

The PDP-8/E main clocks are derived from a 20MHz crystal (That's a 50nS minimum 
timing).

Quoting the DEC Omnibus Standard Document Memory, Address and Data must be 
settled within 50nS
   minimum and no more than 250nS depending on what is going on on the bus.

There is a boot strap board that emulates the front panel with an Arduino and 
an I/O expander.

But to implement Data Break requires much more tight timing.  This bus was 
designed to handle core memory which requires a write after read because the 
read is destructive.


On 9/22/2023 5:52 PM, Chuck Guzis via cctalk wrote:

Stupid question, I know, but someone has to ask it.

Is there some overwhelming reason that the FPGA and associated logic
couldn't be subsumed into an inexpensive 32-bit MCU running at, oh,
200 MHz?  I can't believe that a PDP8 is all that fast...

--Chuck

[cctalk] Re: Good C to FPGA/PLA compiler

[Mike Katz via cctalk]

I have no plans to emulate the CPU.  This is intended to be a board to 
help debug programs and possibly some hardware issues.


On 9/22/2023 6:06 PM, Martin Bishop via cctalk wrote:

Chuck,

Your point is wholly valid, although the core will run more at 1 GHz than 200 
MHz.

The UniBone http://retrocmp.com/projects/unibone is a UniBus board capable of 
monitoring the unibus and of emulating CPU / rotating rust / memory / ...  With 
the bulk of the logic in c on an Arm Processor.  Jay Jaeger has just elaborated 
the UniBone's essentials.

Martin

-Original Message-
From: Chuck Guzis via cctalk [mailto:cctalk@classiccmp.org]
Sent: 22 September 2023 23:53
To: ben via cctalk 
Cc: Chuck Guzis 
Subject: [cctalk] Re: Good C to FPGA/PLA compiler

Stupid question, I know, but someone has to ask it.

Is there some overwhelming reason that the FPGA and associated logic couldn't 
be subsumed into an inexpensive 32-bit MCU running at, oh, 200 MHz?  I can't 
believe that a PDP8 is all that fast...

--Chuck

[cctalk] Re: Good C to FPGA/PLA compiler

[Mike Katz via cctalk]

I plan on controlling the gate array with an RP2040 dual core cortex M0 
running at 133 MHz and 8 PIO processors.


However, the Data Break (DMA) timings on the Omnibus are in the 100nS 
range.  The bus runs 6 different timing signals plus manipulating all of 
the other signals to implement Data Break. I just don't think a micro 
would be fast enough.


That same holds for the break point.  In order to be able to respond to 
address, data, r/w and count for 4 breakpoints in the <1uS window to 
stop the CPU before the start of the next cycle would stress most 
embedded micros (sub  $10 micros anyway).


The PDP-8/E main clocks are derived from a 20MHz crystal (That's a 50nS 
minimum timing).


Quoting the DEC Omnibus Standard Document Memory, Address and Data must 
be settled within 50nS

 minimum and no more than 250nS depending on what is going on on the bus.

There is a boot strap board that emulates the front panel with an 
Arduino and an I/O expander.


But to implement Data Break requires much more tight timing.  This bus 
was designed to handle core memory which requires a write after read 
because the read is destructive.



On 9/22/2023 5:52 PM, Chuck Guzis via cctalk wrote:

Stupid question, I know, but someone has to ask it.

Is there some overwhelming reason that the FPGA and associated logic
couldn't be subsumed into an inexpensive 32-bit MCU running at, oh, 200
MHz?  I can't believe that a PDP8 is all that fast...

--Chuck

[cctalk] Re: Good C to FPGA/PLA compiler

[Mike Katz via cctalk]

My plan is to have both a serial port for connection to a PC/Terminal 
and an I2C output to a multi line display.


Thanks for the suggestion.

On 9/22/2023 4:45 PM, ben via cctalk wrote:

On 2023-09-22 3:16 p.m., Mike Katz via cctalk wrote:

Martin,

The debug board will need to have the following functionality:

1. Read and write to/from memory when the CPU is running using one
    cycle data break (DEC's version of DMA for the PDP-8). Single Cycle
    DMA requires some interesting signaling, including putting the
    priority on the data bus during part of the cycle.
2. Read and write to/from memory when the CPU is halted using front
    panel emulation (something totally different than one cycle data
    break unfortunately)
3. Handle 4 breakpoints (based on address, data, R/W and count) and
    signal the cpu to stop.  I don't know, yet, if there will be enough
    time in the CPU's instruction cycle to top the CPU before the fetch
    of the next instruction.  If this cannot be done in hardware than a
    much more crude break point system can be done in software.
4. There are 96 active signals on the PDP-8/E's Omnibus.  I expect to
    need most or all of them for this project.
5. The Omnibus is an open drain, active low bus where +2.7V to +4.5V is
    a zero and -0.5 to +0.4V is a one.  I don't necessarily need a 5V
    tolerant gate array but what ever I use to interface to the bus will
    need to be.

A full description of the Omnibus can be found here: 
https://bitsavers.org/pdf/dec/standards/EL-00157_00_A_DEC_STD_157_OMNIBUS_Specification_Aug76.pdf


Coding the break point system in some kind of parallel C like 
language seems way easier to me than to write this in gates.  I don't 
have a clue how to design the count registers.


I need to get #'s 1 and 2 working first and then I can dive into #3.

Thanks.


Hexadecimal displays til311, (pulled DIS1417's) can be found on ebay 
for about $5 not counting shipping. This way you have easy to read hex 
or octal numbers.

[cctalk] Re: Good C to FPGA/PLA compiler

[Mike Katz via cctalk]

Martin,

The debug board will need to have the following functionality:

1. Read and write to/from memory when the CPU is running using one
   cycle data break (DEC's version of DMA for the PDP-8). Single Cycle
   DMA requires some interesting signaling, including putting the
   priority on the data bus during part of the cycle.
2. Read and write to/from memory when the CPU is halted using front
   panel emulation (something totally different than one cycle data
   break unfortunately)
3. Handle 4 breakpoints (based on address, data, R/W and count) and
   signal the cpu to stop.  I don't know, yet, if there will be enough
   time in the CPU's instruction cycle to top the CPU before the fetch
   of the next instruction.  If this cannot be done in hardware than a
   much more crude break point system can be done in software.
4. There are 96 active signals on the PDP-8/E's Omnibus.  I expect to
   need most or all of them for this project.
5. The Omnibus is an open drain, active low bus where +2.7V to +4.5V is
   a zero and -0.5 to +0.4V is a one.  I don't necessarily need a 5V
   tolerant gate array but what ever I use to interface to the bus will
   need to be.

A full description of the Omnibus can be found here: 
https://bitsavers.org/pdf/dec/standards/EL-00157_00_A_DEC_STD_157_OMNIBUS_Specification_Aug76.pdf


Coding the break point system in some kind of parallel C like language 
seems way easier to me than to write this in gates.  I don't have a clue 
how to design the count registers.


I need to get #'s 1 and 2 working first and then I can dive into #3.

Thanks.

[cctalk] Good C to FPGA/PLA compiler

[Mike Katz via cctalk]

I'm working on the design for an Omnibus (PDP-8/E) debug board and I am 
not very good at circuit design.  I know there are programs that will 
compile something that looks like C into Verilog/VHDL/Abel/Etc for use 
on some kind of large (more than 64 pins) programmable logic device.


Can any of you recommend a good C like tool for programmable logic?

Thank you,

 Mike

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

Whom ever said youth is wasted on the young was telling a very serious 
truth.


On 9/7/2023 7:12 PM, Tarek Hoteit wrote:
Safe recovery! Yes, the physical human OLD sucks (not the geeky-part 
<- guess that keeps us more functioning)


- - - - - - - - - - - - -
Tarek Hoteit
ta...@infocom.ai
+1 360-838-3675

https://infocom.ai



On Sep 7, 2023, at 5:07 PM, Mike Katz via cctalk 
 wrote:


My sympathies to both of you and wishes for a good and complete recovery.

2 years ago I had a heart attack in my dojo.   8 stents and a 
pacemaker later I was back on the mat in 3 weeks. It was 6 months 
before I was able to go full speed.


Getting old sucks!!!



On 9/7/2023 6:58 PM, KenUnix via cctalk wrote:

Jon,

Yea. It affected my left side. Loss of muscle strength. I am left handed
and lost my strength but luckily can still type albeit slower.

Good thing the keyboard has a backspace key.

Fortunately I still get ideas but it sometimes takes awhile to write 
them

down.

-Ken

On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk 


wrote:


On 9/7/23 17:18, KenUnix via cctalk wrote:

Hi guys.

Since I can't get out due to my stroke, be sure to post plenty of 
snaps

of

the event...


Sorry to hear about that.  I had a very mild stroke 2 years
ago, but it has affected dexterity in my right hand.  My
writing is now horrible (my penmanship was never really
great) and typing is more error prone than before.

Jon

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

My sympathies to both of you and wishes for a good and complete recovery.

2 years ago I had a heart attack in my dojo.   8 stents and a pacemaker 
later I was back on the mat in 3 weeks.  It was 6 months before I was 
able to go full speed.


Getting old sucks!!!



On 9/7/2023 6:58 PM, KenUnix via cctalk wrote:

Jon,

Yea. It affected my left side. Loss of muscle strength. I am left handed
and lost my strength but luckily can still type albeit slower.

Good thing the keyboard has a backspace key.

Fortunately I still get ideas but it sometimes takes awhile to write them
down.

-Ken

On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk 
wrote:


On 9/7/23 17:18, KenUnix via cctalk wrote:

Hi guys.

Since I can't get out due to my stroke, be sure to post plenty of snaps

of

the event...


Sorry to hear about that.  I had a very mild stroke 2 years
ago, but it has affected dexterity in my right hand.  My
writing is now horrible (my penmanship was never really
great) and typing is more error prone than before.

Jon

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

With Dorothy and the Tin Woodsman as their salespeople 藍

I think those would be micro-vaxen because they are only single user.

On 9/7/2023 4:44 PM, ste...@malikoff.com steven--- via cctalk wrote:

On 09/07/2023 2:36 AM AEST Mike Katz via cctalk  wrote:
Does VAX have nothing to do with vacuum cleaners?

Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. We 
had one until recently.
https://www.vax.com.au/

Steve

[cctalk] Setup for VCFMW

[Mike Katz via cctalk]

What time is setup Tomorrow (Friday, 8-Sep-23) for VCFMW?

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

Paul,

I'm not an 11 expert but don't most instruction fetches (or the last 
clock phase on an instruction) cause the pc to increment by one?


On 9/6/2023 12:08 PM, Paul Koning via cctalk wrote:

Reminds me of the "PDP-11 trivia contest" that was held at DECUS, I think on the occasion 
of the 20th anniversary of the PDP-11.  If so that would have been 2000.  I still have the poster 
that went with it somewhere.  And I remember the question I contributed: "On what model and 
under what circumstances will the PC increment by 1?"

paul


On Sep 6, 2023, at 12:36 PM, Mike Katz via cctalk  wrote:

Do you understand "Stop this RIM RAM or I will DEC you"?

Do you know what PDP is an acronym for?

Do you think in PDP-11 Assembler.

Do you know the difference between OS/8 and RTS/8.

Is EMACS your friend?

Can you discuss the advantages of Tops 10 over Tops 20.

Have you ever programmed a DEC 18 bit machine?

Does VAX have nothing to do with vacuum cleaners?

If you can answer yes to any of these I am hosting a "DECnut" pizza party, at 
my house, Saturday, September 9th at 7PM with pizza to be delivered sometime after that.

If you are interested please stop by my table (first 2 tables to the left of the door in 
the "big iron" room).  Look for the PDP-8/E with an RX02 attached.

Please feel free to pass this email on to any DEC fan.

Thanks,

  Mike

[cctalk] Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

Do you understand "Stop this RIM RAM or I will DEC you"?

Do you know what PDP is an acronym for?

Do you think in PDP-11 Assembler.

Do you know the difference between OS/8 and RTS/8.

Is EMACS your friend?

Can you discuss the advantages of Tops 10 over Tops 20.

Have you ever programmed a DEC 18 bit machine?

Does VAX have nothing to do with vacuum cleaners?

If you can answer yes to any of these I am hosting a "DECnut" pizza 
party, at my house, Saturday, September 9th at 7PM with pizza to be 
delivered sometime after that.


If you are interested please stop by my table (first 2 tables to the 
left of the door in the "big iron" room).  Look for the PDP-8/E with an 
RX02 attached.


Please feel free to pass this email on to any DEC fan.

Thanks,

 Mike

[cctalk] Re: Silly question about S-100 and video monitors

[Mike Katz via cctalk]

You are correct for some but I do recall some with a composite output in 
that little switch box as well.  Maybe I'm misremembering from 50 years ago.


On 8/31/2023 6:02 PM, Fred Cisin via cctalk wrote:

On Thu, 31 Aug 2023, Mike Katz wrote:
The roots of this standard go all the way back to the 1930's and 
became a standard in 1940.  By passing the tuner meant bypassing all 
of the filters and demodulation that needed to happen.  Many video 
games of the 70's and early 80's came with 300 Ohm antenna leads and 
an RCA plug with a switch for  modulated or unmodulated signals.


That little switchbox was so that the RF input of the TV could be 
switched between the [normal] antenna, and the RF modulator of the 
Computer/vide game.  With almost all of them, the output was to the 
TV, and the inputs were antenna VS computer/video game


Without that switch, if they were just hooked in parallel, then the 
output of the computer/video game could leak/boadcast out of the antenna.

[cctalk] Re: Silly question about S-100 and video monitors

[Mike Katz via cctalk]

Composite will 99.99% of the time be better than RF modulated due to 
the bandwidth of NTSC (American) Televisions.  The NTSC television 
standard was not what I would exactly call high tech or high 
resolution.  It was 525 scan lines interlaced at 30Hz meaning that there 
was only 262.5 lines every 60th of a second.  If you were very very 
lucky and had a very good television you might get 640 x 480 with alot 
of flicker.  If you want color the resolution went way down due to the 
way that the NTSC standard handled colors to be backwards compatible 
with black and white televisions.


The roots of this standard go all the way back to the 1930's and became 
a standard in 1940.  By passing the tuner meant bypassing all of the 
filters and demodulation that needed to happen.  Many video games of the 
70's and early 80's came with 300 Ohm antenna leads and an RCA plug with 
a switch for  modulated or unmodulated signals.


I remember buying small composite monitors with a single RCA jack on the 
back for < $100 as far back as like 1982.


Usually if the monitor had speakers it was based on a TV without the 
tuner, if it didn't have speakers it was a purpose build monitor.


As the cost of video production came down in the 70's and 80's the cost 
of composite monitors dropped considerably and also started appearing on 
the used market.  I remember buying a black and white square box video 
monitor for like $50 as the Dayton hamfest in the early 80's.


On 8/31/2023 5:11 PM, Fred Cisin via cctalk wrote:

On Thu, 31 Aug 2023, Chuck Guzis via cctalk wrote:

I believe that Sony used some of their portable transistorized TV sets
as monitors, equipping them with SO239 UHF connectors.  I recall having
one of those as well.


Sony's CV and AV series reel to reel portable video recorders used one 
of those.  It was black, and had Rf input, UHF connector, a 14? pin 
rectangular Honda plug, and a slide switch for TV/monitor.  In 1971, I 
once "repaired" one of the college's ones by sliding that switch out 
of the middle position :-)



I got one of those at a flea market, and that was what I had for my 
TRS80.


--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Silly question about S-100 and video monitors

[Mike Katz via cctalk]

OMG Flavor Radio, that brings back memories of working at Radio Shack in 
1977 fresh out of high school.


Thanks for the trip down memory lane and making me feel old again (or is 
that still).



On 8/31/2023 3:52 PM, Chris Zach via cctalk wrote:
Which is weird, since Radio Shack was renowned for putting schematic 
diagrams on so many of their products. My Flavoradio still has the 
schematic on it if a transistor goes bad


CZ

On 8/31/2023 2:48 PM, Fred Cisin via cctalk wrote:

Hence the short text lines on "home" computers.
. . . . . .  Dave Sparks, the RS repair technician, was happy to 
ignore any mods that he understood, so he didn't void the 
warranty.  When his boss objected, he said that since I had brought 
it in with an intact warranty label and paint on the screws, he 
assumed that I had done all of the mods through the vent slots, 
without opening it ("boat in a bottle" :-)


On Thu, 31 Aug 2023, geneb via cctalk wrote:
Fun fact - the "Warranty Void if Removed" tags were and are 
illegal.  The warranty can only be voided if the mfgr can prove the 
thing you did resulted in the problem you're claiming warranty on. :)


eventually codified in the Magnuson-Moss warranty Act, enacted in 
1975, just a few years before RS started pasting those stickers on..


But, they didn't say that modifications voided the warranty, . . .
the warranty was only voided if the sticker was damaged. So, 
modifications were OK if you did them without damaging the sticker 
and/or the painted over screwheads.

http://www.glyptal.com/products/G7526Ftech.pdf

--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Silly question about S-100 and video monitors

[Mike Katz via cctalk]

The probem with RF Modulators is that due to the National Television 
Standards Committee standards for American television there wasn't 
enough bandwidth to display 80 characters x24  lines (or 25 lines with 
status). Generally 64 x 16 was the maxmimum that would be readable on a 
standard black and white TV set.  Any higher resolutions would either 
cause the characters to "tear" or lose horizontal or vertical sync 
completely.


That is why monitors were used.  They were not bound by the NTSC 
standards and were generally made for 80 x 25 or (even 132 x 25 with a 
smaller character set).


On 8/30/2023 3:54 PM, William Sudbrink via cctalk wrote:

There were RF modulators.  See the November 1976 review of the Poly-88 here
(on page 16):

http://cini.classiccmp.org/pdf/DrDobbs/DrDobbs-1976-11-12-v1n10.pdf

Note the reference to the "Pixie Verter".  It is a little cheap circuit
board that takes the composite signal and modulates it onto channel 3.  You
will find references to the Pixie-Verter in a number of publications and
user manuals for early video boards.  The Matrox and the Cromemco Dazzler
and the Ohio Scientific documentation all reference it.  David Ahl in his
"Saga Of A System" magazine article references it.  With that, a TV, video
board, RF modulator and a parallel keyboard were much cheaper than any
serial terminal back then.  The RF modulator was separate from the video
board (usually hung on the back of the TV) for noise reasons.



-Original Message-
From: W2HX via cctalk [mailto:cctalk@classiccmp.org]
Sent: Wednesday, August 30, 2023 3:39 PM
To: General Discussion: On-Topic and Off-Topic Posts 
Cc: W2HX 
Subject: [cctalk] Silly question about S-100 and video monitors

Hi all,

I recently acquired an S-100 computer, and it came with a video card and a
keyboard (3rd party products, not originally equipped with these). I am
trying to figure out the benefits of having a video card and keyboard vs
just using a serial port and terminal. Certainly if the video card supported
graphics, that would be a reason to go that route over a terminal. As for
the keyboard, ok-maybe you need specific keys for a specific application.
But I don't understand the video monitor. I could understand maybe if there
was an RF modulator so that you could use a standard TV. That would save the
builder some money. But this computer just provides composite.

Other than graphics (and maybe some special function keys for an application
on a keyboard), why would an S-100 builder in those days opt to buy a video
card instead of a terminal?

Thanks for the bandwidth.

73 Eugene W2HX
Subscribe to my Youtube Channel: https://www.youtube.com/@w2hx/videos

[cctalk] Re: Silly question about S-100 and video monitors

[Mike Katz via cctalk]

I think you forgot the most common storage back then.  Audio cassette at 
300 or 1200 baud.


On 8/30/2023 5:39 PM, Fred Cisin via cctalk wrote:

On Wed, 30 Aug 2023, Wayne S wrote:
When s-100 machines came out, they were standalone. The serial port 
was for sending serial data not for a terminal. You would have to 
write some software to use it with a terminal.


Of course.

To do anything with it, you needed some input and output.
Either a good front panel, or
a serial port plus software for a terminal, or
a keyboard input with software, plus a video board with software.

paper tape for storage, so as to not have to key in every program evey 
time, or

a tape drive, or a disk drive.

By the end of the 1970s, computers were being sold with terminal or 
keyboard/video hardware and software, and then disk drives and an 
operating system.  BASIC on paper tape, ROM, or disk, . . .


By the end of the 1970s, you did not need to be an 
electronics/comupter hobbyist to buy and use a personal computer.

It became possible, without even a scope and soldering iron!


--
Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Silly question about S-100 and video monitors

[Mike Katz via cctalk]

/115,200 in the S100 era was also rare. It was usually 9600 or 19200 at 
the top end/


That is true.  I remember setting my serial board for external baud rate 
and the SWTPC CT-82 terminal to generate the baud rate and I think it 
was like 38,400 maximum.


My VT-220 maxes out at 9600 and my VT-330+ maxes out at 19,200.

Remember the teletypes ran at 110 baud or slower.  The decwrite and GE 
Terminet were speed demons at 300 and 1200 baud.


On 8/30/2023 3:02 PM, Warner Losh wrote:



On Wed, Aug 30, 2023 at 1:52 PM Mike Katz via cctalk 
 wrote:


I had a video board and keyboard on my Gimix SS-50 system.

Why?

1.  The video board/monitor is much faster than a terminal even at
115,200 baud.


115,200 in the S100 era was also rare. It was usually 9600 or 19200 at 
the top end.


2.  A Video board, keyboard and monitor was way cheaper back then
than a
terminal (Yes there was the SWTPc CT64 and the Lear Siegler ADM-3A
kits,
but fully loaded they weren't all that cheap).
3.  If the video board supports any kind of graphics that is another
reason.  The Gimix video board supported graphics with a RAM
character
generator.


4. It's a lot less code to directly splat characters into memory than 
to generate
all the escape sequences you need to 'draw' anything interesting (be 
it a game,

a graph or just an emacs buffer).

I got into this just after the S100 era, and I opted for the Rainbow 
because it

was both a terminal I could connect to other systems, and a system with an
internal graphics card. The terminal had completed the move inside the 
computer
after starting out life as a computer added onto the terminal. DECs 
terminals
followed this path. Many of the S100 systems that had graphics cards 
were also

chasing after newish workstations that were just starting to be built.

Warner

On 8/30/2023 2:38 PM, W2HX via cctalk wrote:
> Hi all,
>
> I recently acquired an S-100 computer, and it came with a video
card and a keyboard (3rd party products, not originally equipped
with these). I am trying to figure out the benefits of having a
video card and keyboard vs just using a serial port and terminal.
Certainly if the video card supported graphics, that would be a
reason to go that route over a terminal. As for the keyboard,
ok-maybe you need specific keys for a specific application. But I
don't understand the video monitor. I could understand maybe if
there was an RF modulator so that you could use a standard TV.
That would save the builder some money. But this computer just
provides composite.
>
> Other than graphics (and maybe some special function keys for an
application on a keyboard), why would an S-100 builder in those
days opt to buy a video card instead of a terminal?
>
> Thanks for the bandwidth.
>
> 73 Eugene W2HX
> Subscribe to my Youtube Channel:
https://www.youtube.com/@w2hx/videos
>

[cctalk] Re: Silly question about S-100 and video monitors

[Mike Katz via cctalk]

I had a video board and keyboard on my Gimix SS-50 system.

Why?

1.  The video board/monitor is much faster than a terminal even at 
115,200 baud.
2.  A Video board, keyboard and monitor was way cheaper back then than a 
terminal (Yes there was the SWTPc CT64 and the Lear Siegler ADM-3A kits, 
but fully loaded they weren't all that cheap).
3.  If the video board supports any kind of graphics that is another 
reason.  The Gimix video board supported graphics with a RAM character 
generator.


On 8/30/2023 2:38 PM, W2HX via cctalk wrote:

Hi all,

I recently acquired an S-100 computer, and it came with a video card and a 
keyboard (3rd party products, not originally equipped with these). I am trying 
to figure out the benefits of having a video card and keyboard vs just using a 
serial port and terminal. Certainly if the video card supported graphics, that 
would be a reason to go that route over a terminal. As for the keyboard, 
ok-maybe you need specific keys for a specific application. But I don't 
understand the video monitor. I could understand maybe if there was an RF 
modulator so that you could use a standard TV. That would save the builder some 
money. But this computer just provides composite.

Other than graphics (and maybe some special function keys for an application on 
a keyboard), why would an S-100 builder in those days opt to buy a video card 
instead of a terminal?

Thanks for the bandwidth.

73 Eugene W2HX
Subscribe to my Youtube Channel: https://www.youtube.com/@w2hx/videos

[cctalk] Re: VCFMW vendor tables

[Mike Katz via cctalk]

/

simply don’t watch it.  Don’t blame the medium.

/
I'm sorry but I have to disagree.  The way that discord presents the 
information vs a forum style or even Facebook style is, to me, very very 
distracting and hard to communicate across.  The constant chatter, distracting 
graphics and animations, etc. make it difficult, again for me, to find and 
clean the information that I am looking for.

In my opinion, the forum construct is a much much better way to disseminate 
information and carry on category and subject oriented conversations.  Just 
jump on the VCF DEC forum and see that there are conversations going on from 
PDP-9 Restoration to OS/8 Internals to PDP-11 Operating systems.  And since 
there are forums for most every vintage computer category you don't get 
assailed with noise that you aren't interested in like in the mailing lists.

On 8/30/2023 1:30 PM, Wayne S wrote:

This dislike of “Discord” has touched a nerve for me.  It’s also one of the 
reasons the cctalk list has lost most of it value.
Discord is a collection of channels most devoted to specific subjects that you 
more or less subscribe to. It’s just a server and you need an invite to join a 
group. I’m in the Classic computer group and find it to be filled with 
knowledge people willing to share that knowledge with others.
Saying you don’t like “Discord” is like saying you don’t like TV. If you don’t 
like the content, simply don’t watch it.  Don’t blame the medium.


Sent from my iPhone


On Aug 30, 2023, at 11:11, Mike Katz via cctalk  wrote:

I have to second the motion.  In my opinion in general social media is a waste 
of time and energy.

I understand the time it takes to run VCF but to have multiple possible 
different places (webiste, ICM, discord, etc) to get information is a bit much, 
especially for us old farts.

Discord contributes as much noise as it does relevant information.

My suggestion would be to use the website as the primary source of information 
and write Java/Jacascript/PDP/Json code to take any website updates and forward 
them to any other desired channel.

That way all channels get the same information virtually simultaneously without 
any human effort than the the info on the main website.


On 8/30/2023 11:35 AM, Tom Uban via cctalk wrote:

On 8/30/23 11:25 AM, Seth Morabito via cctalk wrote:
On Wed, Aug 30, 2023, at 7:26 AM, William Donzelli via cctalk wrote:

All the VCFMW info is on the Discord server.

I swear to God, Discord will be the end of the open Internet, it's where 
information goes to die. I hate it with every fiber of my being. And yes, I use 
it, I'm on many servers. I'm still allowed to detest it.

-Seth

I have heard of Discord, but have not had a need to use it. Odd 
thathttps://vcfmw.org/  does not have an obvious link for Discord if it is 
where we are expected to find useful information. Would I need to have a 
Discord account (and be a member of some group) to see this information?

--tom

[cctalk] Re: VCFMW vendor tables

[Mike Katz via cctalk]

I have to second the motion.  In my opinion in general social media is a 
waste of time and energy.


I understand the time it takes to run VCF but to have multiple possible 
different places (webiste, ICM, discord, etc) to get information is a 
bit much, especially for us old farts.


Discord contributes as much noise as it does relevant information.

My suggestion would be to use the website as the primary source of 
information and write Java/Jacascript/PDP/Json code to take any website 
updates and forward them to any other desired channel.


That way all channels get the same information virtually simultaneously 
without any human effort than the the info on the main website.


On 8/30/2023 11:35 AM, Tom Uban via cctalk wrote:

On 8/30/23 11:25 AM, Seth Morabito via cctalk wrote:

On Wed, Aug 30, 2023, at 7:26 AM, William Donzelli via cctalk wrote:

All the VCFMW info is on the Discord server.
I swear to God, Discord will be the end of the open Internet, it's 
where information goes to die. I hate it with every fiber of my 
being. And yes, I use it, I'm on many servers. I'm still allowed to 
detest it.


-Seth
I have heard of Discord, but have not had a need to use it. Odd that 
https://vcfmw.org/ does not have an obvious link for Discord if it is 
where we are expected to find useful information. Would I need to have 
a Discord account (and be a member of some group) to see this 
information?


--tom

[cctalk] Re: PDP-8/L $15,000

[Mike Katz via cctalk]

DEC did make the Interprocessor Buffer (M8326) for the Ominibus. That 
allowed for relatively high speed communications between machines.  You 
could also do some kind of serial network like Lantastic.    I know some 
company made an SDLC board set for the omnibus.


On 8/30/2023 8:04 AM, Paul Koning via cctalk wrote:



On Aug 29, 2023, at 8:46 AM, Chris Zach via cctalk  
wrote:



-BUT- That does not mean it *can't* be restored, only that $15,000 is
ridiculous for a machine that clearly needs an expert with time and money.
b

True, it is a silly price. I was thinking about this on the forum: If someone 
offers to buy one of my fully running 8/L's for 6k I'll put in an offer on this 
one for 3k and restore it. The extra 3k will be used to buy beer to help me 
forget about all of the little mouse ghosts I'm going to find. :-)

I'd offer 3k for it outright, but to be honest I can't have 3 pdp8/L's AND an 
8/e. At some point I'd have to wire them into some sort of nightmare SMP 
pdp8

Or DECnet/8, though I suspect an 8/L can't run that.

paul

[cctalk] Re: PDP-8/L $15,000

[Mike Katz via cctalk]

I forgot to mention that I was playing the Focal version on a PDP-8/L 
coincidentally.


On 8/28/2023 4:16 PM, Mike Katz via cctalk wrote:
I played the graphics lunar lander on a PDP-9 with a graphics display 
and push buttons (not the sw) in a back room in the Kiewit Computation 
Center at Dartmouth in like 1972 or 1973, the same time I was playing 
it in text on a teletype ASR-33 in Focal.  Hand typed in and punched 
to paper tape.


On 8/28/2023 4:06 PM, Paul Koning via cctalk wrote:


On Aug 28, 2023, at 4:55 PM, Will Cooke via cctalk 
 wrote:




On 08/28/2023 3:48 PM CDT Paul Koning via cctalk 
 wrote:


Lander, in FOCAL? The only one I know is for the GT40, in assembler.

paul

Apparently the original version was in FOCAL.
https://www.cs.brandeis.edu/~storer/LunarLander/LunarLander.html

Will

Interesting.  And amazingly short.

I flipped through some of those articles.  There's a version from 
around those early times not mentioned, for the CDC 6000 mainframe 
computer.  It used the console display, dual green text displays that 
could also do graphics (clumsily, because the API was a dot drawing 
one, not line vectors).


What's unusual about that one is that it's a pilot's point of view 
display -- it shows you the lander's instruments and a view out the 
windows, rather than an outside observer view as the GT40 version 
does.  I played it a few times, it was hard -- I never managed to 
land it.  One of the system staff (at University of Illinois PLATO 
project) was rumored to have a fast way to land: flip upside down, 
blast rockets, flip right side up, blast some more for a soft landing.


paul

[cctalk] Re: PDP-8/L $15,000

[Mike Katz via cctalk]

I hate what epay is doing to our hobby.

I prefer to sell and trade between our selves as reasonable prices 
understanding that a lot of what we do is sweat equity.


On 8/28/2023 3:56 PM, Sellam Abraham via cctalk wrote:

On Mon, Aug 28, 2023 at 11:50 AM Mike Katz via cctalk 
wrote:


However, epay does charge an insertion fee so they will have to pay even
when it doesn't sell.


It's thirty five cents, and they usually don't charge it until it actually
sells.  Then they dock you another 13.25% on the total the buyer pays
(including tax and shipping).  But then you stand to make up a good amount
of that because the buyer pays retail for shipping while you buy it at a
discount and you get to keep the spread.

But it's a Pyrrhic victory :D

Sellam

[cctalk] Re: PDP-8/L $15,000

[Mike Katz via cctalk]

I played the graphics lunar lander on a PDP-9 with a graphics display 
and push buttons (not the sw) in a back room in the Kiewit Computation 
Center at Dartmouth in like 1972 or 1973, the same time I was playing it 
in text on a teletype ASR-33 in Focal.  Hand typed in and punched to 
paper tape.


On 8/28/2023 4:06 PM, Paul Koning via cctalk wrote:



On Aug 28, 2023, at 4:55 PM, Will Cooke via cctalk  
wrote:




On 08/28/2023 3:48 PM CDT Paul Koning via cctalk  wrote:

Lander, in FOCAL? The only one I know is for the GT40, in assembler.

paul

Apparently the original version was in FOCAL.
https://www.cs.brandeis.edu/~storer/LunarLander/LunarLander.html

Will

Interesting.  And amazingly short.

I flipped through some of those articles.  There's a version from around those 
early times not mentioned, for the CDC 6000 mainframe computer.  It used the 
console display, dual green text displays that could also do graphics 
(clumsily, because the API was a dot drawing one, not line vectors).

What's unusual about that one is that it's a pilot's point of view display -- 
it shows you the lander's instruments and a view out the windows, rather than 
an outside observer view as the GT40 version does.  I played it a few times, it 
was hard -- I never managed to land it.  One of the system staff (at University 
of Illinois PLATO project) was rumored to have a fast way to land: flip upside 
down, blast rockets, flip right side up, blast some more for a soft landing.

paul

[cctalk] Re: PDP-8/L $15,000

[Mike Katz via cctalk]

it's been there for over a week.

In unknown condition.

I think that price is disgustingly high.

I would love to have one but that is the down payment on a car, not a 
used computer.  Antique or not.


On 8/28/2023 12:30 PM, Bill Degnan via cctalk wrote:

It can be yours for only $15,000 plus shipping
https://www.ebay.com/itm/126067408991

sheesh.

Bill

[cctalk] Re: PDP-8/L $15,000

[Mike Katz via cctalk]

However, epay does charge an insertion fee so they will have to pay even 
when it doesn't sell.


On 8/28/2023 1:37 PM, Bill Degnan via cctalk wrote:

On Mon, Aug 28, 2023, 1:46 PM Chuck Guzis via cctalk 
wrote:


On 8/28/23 10:30, Bill Degnan via cctalk wrote:

It can be yours for only $15,000 plus shipping
https://www.ebay.com/itm/126067408991


Well, if that doesn't fancy your tickle, you can have an equally
rough-looking Morrow MD-1 for only $3500.

https://www.ebay.com/itm/126067197438

--Chuck


I think some Ebay sellers simply overpriced an item when they know it's
probably valuable but they're not sure how much to sell for.  They will
wait for people to contact and say, "your price is way too high, you might
sell if you charged $n instead."

It's not an illogical tactic.

Bill

[cctalk] I am looking for the Popular Electronics Digital Logic Micro Lab ( SWTPC Logic Demon)

[Mike Katz via cctalk]

This was the kit that matched the article in April 1970 Issue of Popular 
Electronics.


Yes I can build one from modern parts but I used one of these in 1972 
and I would love to get my hands on one, at a reasonable price.


Here is a link to the article:

https://www.retrotechnology.com/restore/PE_microlab2.pdf 



https://deramp.com/swtpc.com/PopularElectronics/Apr1970/MicroLab_Photo.jpg

[cctalk] Good Inventory Program for keeping track of my DEC boards, parts, computers, etc?

[Mike Katz via cctalk]

I'm looking for a good inventory program to help me keep track of all of 
my PDP-8 stuff.


I would like to keep track of physical location, board etch revision, 
board modification revision, bus type, where used, etc.


If you have any good ideas, please let me know.

I'm using a simple spreadsheet for now and it's not what I'm looking for.

Thank you.

[cctalk] Re: Talking PDP11

[Mike Katz via cctalk]

I originally used R-2R DACs but I was lucky enough to be able to buy a 
couple of DAC08 chips at Radio Shack and built a circuit using 74LS244 
latching buffers so that I could drive both channels of a single 8-bit 
parallel port and 2 extra control lines (Select and Strobe).


On 7/11/2023 6:43 AM, ste...@malikoff.com steven--- via cctalk wrote:

On 07/10/2023 11:31 PM AEST Mike Katz via cctalk  wrote:
Way back in the 80's I was able to do stereo 4 part harmony on a 2 MHZ
6809 using two 8-bit D/A converters.

Much the same here. I recounted this on VCFed a few months ago about building a 
simple 2-chip 8-bit ladder DAC with one-transistor amplifier for my Applied 
Technology DG680 S100 machine back in the early 80s from this absolutely 
excellent BYTE article on how to do polyphonic synthesis on a microcomputer 
(KIM-1):

https://archive.org/details/byte-magazine-1977-09/page/n63/mode/2up

A schoolfriend who had an Apple ][ and had not done any Z80 machine code before 
asked for me to hand him my Zaks book, upon which he wrote out one attempt in 
Z80, crossed it out and wrote a second version. Which worked perfectly. For the 
music piece I got it to play four-voice polyphony after painstakingly encoding 
Bach's Praeludium in C Major from my mothers' collection of piano music scores.

A few years ago I had thoughts about porting the 6502 code to the PDP-11 and 
use the same sort of ladder DAC. Not sure if the slimline 11/05 would be fast 
enough for anything too high frequency, but if it was, the slimline 05's power 
supply could then temporarily come out and be perhaps be powered off some beefy 
batteries in that space, along with a small 1970s transistor amp and 1970s 
headphones topped off with a leather shoulder strap to lug it around like a 
giant Walkman.

[cctalk] Re: Talking PDP11

[Mike Katz via cctalk]

Doug,

You could also do some kind synthesizer using fixed frequencies and 
pulse width modulation.


It would not be that difficult to add attack and decay and even be 
polyphonic.


You could either use the keyboard for single tone with different keys to 
change the PWM, Attack, Decay, white noise, pink noise, and volume of 
each channel or you could write some kind of interpreter that would play 
music from some kind of text file.


Way back in the 80's I was able to do stereo 4 part harmony on a 2 MHZ 
6809 using two 8-bit D/A converters.


If you want to generate different waveforms they can be stored in memory 
and the faster you cycle through them the higher the frequency.  
However, the finer the resolution the greater the memory requirement.


Square waves are the easiest to produce as they don't need waveform 
tables.  Just remember you need to remember the Nyquist frequency. You 
need to be writing to the D/A at at least double the frequency of the 
tone you are trying to product.  However,  twice the frequency only 
allows you to produce square waves.


I would look at the output of your program on an oscilloscope to see if 
there is any high frequency artifacts that you might want to filter out 
electronically.


Have fun and please post some recordings.

On 7/9/2023 10:07 PM, Martin Bishop via cctalk wrote:

Doug

You have the essence of what it can do and how it might do it, an old iron 
PDP-11 / LSI-11 can't organically do the signal processing necessary to go from 
a compact signal representation to audio.  That said you could use a one bit 
output, which would for efficiency require a serialiser, to drive a sigma delta 
converter, e.g. 
https://digilent.com/shop/pmod-i2s2-stereo-audio-input-and-output/, to convert 
a word stream to sound.  Generating the I2S bit stream is of course an XFU, 
probably doable from a DRV11 type interface, with a fair bit of logic or your 
favorite microcontroller as intermediary.

A 7 kHz sample rate will not be easily achieved, unless you can use an external clock or plug in an 
"optimal" oscillator, e.g. the classic example (but not for this requirement) is one 
running at a multiple of baud rate frequencies, 12M288 Hz say.  On these old boards, frequency = 
oscillator / prescaler / divisor.  Generally, the divisor is the "round" number and the 
frequency is the fractional mess.  Also, the prescalers may be powers of two, ten, or 1/2/5 : YMMV.

The sort of thing you could demonstrate as audio output from your hardware is 
either Morse or audio composed of phonemes.  The Morse would require some 
evolution of the test generator I described and a little tapering of the attack 
/ decay of the di dah dit sounds to avoid harshness, or could be done from 
canned waveforms (returning to 0V).  The phonemes might generate text to speech 
of 1980's (i.e. contemporary period) standard.

Have fun

Martin

-Original Message-
From: Douglas Taylor via cctalk [mailto:cctalk@classiccmp.org]
Sent: 10 July 2023 02:20
To: Martin Bishop via cctalk 
Cc: Douglas Taylor 
Subject: [cctalk] Re: Talking PDP11

Wow! Actual engineers responding...

It looks like I could only do the most rudimentary audio.

1. Sample Rate: You got maybe 20K samples to store in lower memory.  At 7KHz 
sample rate that would allow 3 seconds of audio.  Voice only.
2. Samples: They must be 12 bits. Converting a modern audio clip requires, band 
filtering, resampling and mapping to 12 bit integers. Could be done in python, 
they have libraries.
3. Clocking output:  I have a KMV11, but never programmed  around it.
4. Amplify output: AAV11-C produces -10 to +10 volts, have to divide this down 
for input to an audio amp.

In the end I will have undone all the advances made in digital audio in the 
last 30 to 40 years.

Doug

On 7/9/2023 4:09 PM, Martin Bishop via cctalk wrote:

You just did use it to play "audio" :<)

The 6 us settling time corresponds to a sampling rate of ~167 kHz, not that you 
will ever get there or would wish to.

The theoretical (real) sampling rate required for a given bandwith is
Fs = 2 Bw.  That requires brick wall filters and it is a lot of work
to get close without significant distortion.  These old DACs are all
but certain to use ladder circuits [see e.g.
https://en.wikipedia.org/wiki/Resistor_ladder] the settlng time will
mostly come from the output buffer [see e.g.
https://www.analog.com/en/technical-articles/ltc1668-dac-lt1807-opamp-
achieve-90ns-settling-to-16bits-83db-sfdr-small-footprint.html for
bleeding edge examples].  To see something other than ringing on a
scope you want at least 10 samples per cycle, e.g. for 3 kHz bandwidth
(i.e. 0 - 3 kHz frequency coverage) output at 30 kHz or greater.  A
low pass (reconstruction in the argot) filter will round off the
corners - set the corner just above the passband

DMA, a local FIFO or at least double buffering are the minimum to
avoid sample jitter.  On basic hardware you will probably have to do
what you can with a 

[cctalk] Re: Found the DSM orange manual

[Mike Katz via cctalk]

I'm in the western suburbs of Chicago but if the manual is unbound (3 
ring or 18 hole cerlock) where the pages will fit into a document feeder 
I have a Xerox copier/printer/scanner that can do double sided scanning.


You pay postage both ways, I am happy to scan it for you.

   Mike

On 6/30/2023 8:15 AM, Paul Koning via cctalk wrote:



On Jun 30, 2023, at 3:42 AM, Chris Zach via cctalk  
wrote:

Okies. Another unique thingie in my life, need to get it out there.

So any suggestions on companies that can do the scans in or around Baltimore 
MD? I'd do it for endless beer privileges at future meets/get togethers :-)

CZ

I've used scanning services at Staples.  In my case, large format scanning, but 
I think the store I went to also had a letter size scanner with a feeder.

Another possibility would be to find someone nearby interested in helping who works at a company 
that uses modern copiers/scanners/fax machines.  Copiers are often "digital copiers" 
which means they are actually a scanner feeding a printer, and "scan to USB stick" tends 
to be one of the features.  Those will scan at typical office copier speeds.  Some will do the job 
in color, if you need that.

paul

[cctalk] Re: How much memory?

[Mike Katz via cctalk]

I was at a Comdex once in Chicago where the featured speaker was Bill 
Gates and he said that Microsoft would never write a program that needed 
more than 256K of memory.


A few years later, Microsoft Exchange Server required a minimum of 256MB 
of memory to run.


Just for comparison my new laptop has 128GB of memory.

Let's not write better code, lets just add more memory and faster 
processors  <- Microsoft Programmers Mantra

[cctalk] Re: IBM RT Graphics

[Mike Katz via cctalk]

I know that VGA used analog signals and sync rather than digital signals.

On 6/7/2023 1:44 PM, Will Cooke via cctalk wrote:



On 06/07/2023 1:26 PM CDT Jonathan Katz via cctalk  
wrote:


Hello!

I have an IBM 6152 aka IBM RT system I rescued. (It may be a 6151?)
I'm 90% sure it has colour graphics. The system does seem to POST
correctly (according to the LED on the front) but the CRT is dead. I'm
wondering if anyone has built an adapter to hook this to a VGA
monitor.

I'm a bit confused by the pinout. It has high and low bits for the RGB
(and associated grounds for each colour.) So I'm not sure how that
would work hooking to a more modern monitor.
http://bio.gsi.de/DOCS/IBM/615x/faqshard.html

Otherwise I need a crash course in fixing CRTs.

--
-Jon
+44 7792 149029

I am not familiar with any of that equipment, but from the description here 
http://bio.gsi.de/DOCS/IBM/615x/faqshard.html#h33. it appears the video is two 
bits of ttl level data for each color.  That is how EGA did it, which I think 
was about the same time frame (1985 ish.). The scan rates seem rather close to 
EGA as well.  It might be worthwhile to look into EGA interfacing.

Will

[cctalk] Re: First non-IBM PC-DOS Compatible PC

[Mike Katz via cctalk]

I remember running SCO Xenix on a generic 286 with 1MB main RAM and an 
Intel Above Board with 4MB of RAM.  The Above Board board cost $4000 
with the 4MB of RAM on it at the time.


The Above Board was populated with 256K x 1 DRAMS so it had 128 chips on 
it.   64 on the main board and 64 on a daughter board.


Now a Raspberry Pi Zero 2 W has a lowly 512MB

On 6/6/2023 9:22 AM, Chuck Guzis via cctalk wrote:

On 6/6/23 04:25, Bill Degnan via cctalk wrote:

There were a articles in the more technical journal-type mags 1981/82 that
discussed porting IBM DOS to non IBM 8088 systems that go into the
mechanics of it.  DOS v 1.25 was the OEM version for the early ports.
*indirectly* from these you might find references to IBM BIOS porting and
who did it, there.  I have only print copies no scans.

I was there, doing just that.  Initially, we at Durango didn't think
that strict 5150 compatibility at the BIOS level was necessary for the
Poppy.  In fact, as OEMs, DOS 1.25 was delivered with only a sample
IO.SYS meant as a "skeleton".  MS-DOS text mode, like CP/M, was
considered to be good enough.

In fact, MSDOS was never intended to be the ultimate target, but rather
an interim goal as we waited for Intel to complete the kernel for Xenix
on the 80286.  Right from the first unit, we had sockets for both the
80186 and the 80286.  Console I/O was done via serial connection.

It's a shame that few know about the early 80286 systems.

--Chuck