Re: Int 13h buffer 64k boundaries

[Guy Sotomayor Jr via cctalk]

> On Apr 19, 2018, at 8:55 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 04/19/2018 07:56 PM, Guy Sotomayor Jr wrote:
> 
>> As to why IBM entered the PC market, the rumor was (at least at the time
>> within IBM) was that T.J. Watson, Jr. was at an employee’s house and saw
>> an Apple II.  He said that he wanted to have IBM branded computers in IBM
>> employees homes.  That was how the IBM PC project was kicked off.
> 
> But it wasn't clear at all what IBM intended the PC for.  Cassette tape,
> TV interface and anything but state-of-the-art design
> 
> The best part of the 5150 IMOHO, was the keyboard.

It was a variant of the keyboard that was used on the System/23.  The basic
keyboard technology was used in a lot of IBM keyboards at the time.

[snip]

> 
> My general impression is that IBM made the 5150 product, without the
> faintest idea of how they were going to sell it.
> 

It was IBM’s answer to the Apple II and various S-100 systems so it was
stripped down for a “low” entry price and/or added with other stuff.  It was
designed to be easy to interface to so that others could make peripherals.

It was really following the model of what other “home” computers at the
time were doing.  It was also a bit of an experiment and in that respect
you’re correct.  They didn’t know what it would be used for nor how to
sell it as it was *so* far outside of the normal IBM product lines.

TTFN - Guy

Andromeda SCDC Qbus controller question

[Douglas Taylor via cctalk]

I just got one of these and wanted to configure it via the 10 pin RS232 
port on the board.


Is the port a standard DLV11-J type?

I have one of those D-bit DLV11-J to DB25 adapters but not getting any 
response.


Any info on the few jumpers on the board?

Doug

Re: Int 13h buffer 64k boundaries

[Chuck Guzis via cctalk]

On 04/19/2018 07:56 PM, Guy Sotomayor Jr wrote:

> As to why IBM entered the PC market, the rumor was (at least at the time
> within IBM) was that T.J. Watson, Jr. was at an employee’s house and saw
> an Apple II.  He said that he wanted to have IBM branded computers in IBM
> employees homes.  That was how the IBM PC project was kicked off.

But it wasn't clear at all what IBM intended the PC for.  Cassette tape,
TV interface and anything but state-of-the-art design

The best part of the 5150 IMOHO, was the keyboard.

By the time one got through equipping the 5150 with floppy drives, as
display and memory, it ran into a pretty good pile of money.  It was
also clear that IBM didn't have any idea of how to sell it.  I remember
going to the regional IBM sales office (was that on Arques? It's been
too lnng), purchase order in hand, wanting to pick up 10 of the 5150s.
Nobody really know what we were asking for--finally, someone showed up
and told us that the lead time would be 12 weeks ARO.  We went down to
Computerland and bought out their stock that evening.

I recall the scuttlebutt that went on before the official 5150 product
announcement.  IBM had just announced its 68K-based lab computer.  There
were those who were hoping for a 68K PC, but I figured that there was no
way that IBM would jeopardize their CS9000 sales.

But there were certainly other 8086-based PCs out before the 5150--some
quite a bit more evolved.

I recall that Bill Morrow sold his Z80-based business package (MD2,
printer and monitor) bundled with software for about 1/2 or less than
the price of a minimally disk-capable 5150 with monitor.

My general impression is that IBM made the 5150 product, without the
faintest idea of how they were going to sell it.

--Chuck

Re: Int 13h buffer 64k boundaries

[Guy Sotomayor Jr via cctalk]

> On Apr 19, 2018, at 4:16 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 04/19/2018 12:14 PM, Fred Cisin via cctalk wrote:
> 
>> I have no difficulty admitting that I didn't, and don't, have
>> Chuck's level of experience and knowledge. My entire venture into
>> microcomputers was a hobby that got out of hand.
> It's not so much expertise, but where you start your investigations.
> 
> Right when I peered into the 5150, I saw the 8237 DMA controller (first
> cousin to the 8257) and recognized it from my 8-bit (8085) days.  It was
> immediately obvious that IBM had taken a bunch of legacy 8 bit
> peripheral chips and shoved them into the PC.   In fact, the 5150 was
> surprising in that how primitive the engineering was--something you
> didn't expect from a high-tech pioneer like IBM.  So the DMA address
> space had to be 16 bits with simple bank select--using a disk controller
> chip that was design to be used with 8 inch drives.

As I have mentioned previously, the 5150 was done by a relatively small
team and they leveraged hardware from a product that had been released
a short time prior to the 5150.  That product was the System/23 which was
based on the 8085.  The importance of the System/23 cannot be overstated
as it was the first IBM product that featured a non-IBM designed CPU.

It is also the case that the entire team that developed the 5150 HW and BIOS
were all from the System/23 team.  The XT-bus was the way it was because
it was the System/23 peripheral bus turned 180-degrees so that “cheap” PC
cards could not be used in the System/23.

The fact that it used “primitive” engineering was actually a design goal.  The
point of the 5150 was to create something that was simple to build and had
a simple design.  Due to the shoestring (for IBM) budget, the team leveraged
a lot from the System/23.

As to why IBM entered the PC market, the rumor was (at least at the time
within IBM) was that T.J. Watson, Jr. was at an employee’s house and saw
an Apple II.  He said that he wanted to have IBM branded computers in IBM
employees homes.  That was how the IBM PC project was kicked off.

BTW, I was on the System/23 team (wrote a fair amount of the ROM code)
and I knew all of the folks on the PC team.  Dr. Dave Bradley (of CTRL-ALT-DEL
fame) had the office across the hall from mine and discussed a lot of the
goings on for what would become the 5150.

TTFN - Guy

Re: Int 13h buffer 64k boundaries

[Chuck Guzis via cctalk]

On 04/19/2018 05:33 PM, Jim Brain via cctalk wrote:

> Someday, the products and software designed and built by the folks in
> this list will be judged by those who follow us.  Possibly the rest of
> you have worked in industries where you were allowed to use new
> solutions, you had ample time to design and develop, and your marketing
> departments priced your solutions at a reasonable price point, but I've
> not had those luxuries.  Thus, I want to be fair to those before me who
> created things like the IBM PC architecture, not because it is a great
> architecture, but because they shipped a real product that added value
> for many folks and did so while working inside a company not known for
> agility.  The folks who did that deserve my respect, and when I am gone
> and folks look at my design choices, I hope they will respect me for
> doing what I could given the constraints I faced.

My view is that it probably won't matter.  Technology is moving so fast
that it won't be long before yesterday's PCs will be viewed with the
attitude that today's of "retro" PC enthusiasts view an 082 sorter.
Recall that, in 1955, a lot of common culture viewed that as a
"computer". (I can probably come up with a couple of contemporary cinema
examples where that was exactly how one was portrayed).

When I put on my future-view goggles and read about the steps being made
today in AI and associated hardware technology, all of this "personal
computer" hardware will seem just as primitive.

Consider that the 082 dates from 1949 and the last unit rolled off the
line in 1978.  Now consider how antiquated a 10 year old mobile phone is
viewed by most people.

--Chuck

Re: Int 13h buffer 64k boundaries

[Jim Brain via cctalk]

On 4/19/2018 6:16 PM, Chuck Guzis via cctalk wrote:

So, at the time, looking at the 5150, it was an overpriced primitive
implementation using a 1970s CPU.   Many people at the time thought it
would be less popular than the 5100.
While I won't argue the technical merits of your position, I feel like 
we apply revisionism at times to these things.


I would argue that some engineer in IBM ranks was passionately trying to 
convince IBM brass that IBM needed to have a stake in the personal 
computer space, lest other companies swallow up the market.  IBM, 
lumbering giant that it was, probably was reluctant to mess around with 
toy computers (their opinion no doubt) at all. But, someone (or 
someones) won the battle, and someone else had the inspirational idea to 
use off the shelf components, as opposed to having an IBM-branded and 
designed CPU, etc.


Sure, they used old stuff, but it was working stuff, and I think the 
goal was to get something to market as quickly as possible.  Being 
overpriced was IBM Marketing's touch (you call it overpriced, as I 
manufacturer, I call it capitalism at work).


Why do I even post this?

Someday, the products and software designed and built by the folks in 
this list will be judged by those who follow us.  Possibly the rest of 
you have worked in industries where you were allowed to use new 
solutions, you had ample time to design and develop, and your marketing 
departments priced your solutions at a reasonable price point, but I've 
not had those luxuries.  Thus, I want to be fair to those before me who 
created things like the IBM PC architecture, not because it is a great 
architecture, but because they shipped a real product that added value 
for many folks and did so while working inside a company not known for 
agility.  The folks who did that deserve my respect, and when I am gone 
and folks look at my design choices, I hope they will respect me for 
doing what I could given the constraints I faced.


Jim

Re: Int 13h buffer 64k boundaries

[Fred Cisin via cctalk]

I have no difficulty admitting that I didn't, and don't, have
Chuck's level of experience and knowledge. My entire venture into
microcomputers was a hobby that got out of hand.


On Thu, 19 Apr 2018, Chuck Guzis via cctalk wrote:

It's not so much expertise, but where you start your investigations.
Right when I peered into the 5150, I saw the 8237 DMA controller (first
cousin to the 8257) and recognized it from my 8-bit (8085) days.  It was
immediately obvious that IBM had taken a bunch of legacy 8 bit
peripheral chips and shoved them into the PC.   In fact, the 5150 was
surprising in that how primitive the engineering was--something you
didn't expect from a high-tech pioneer like IBM.  So the DMA address
space had to be 16 bits with simple bank select--using a disk controller
chip that was design to be used with 8 inch drives.
The Technical Reference BIOS listing confirmed the suspicion that the
5150 implementation couldn't cross 64K banks.  It had nothing to do with
DOS, per se.


Of course not.  But WHY didn't DOS programs, such as FORMAT, check whether 
their buffers were in usable places?   Not a common problem in DOS 1.0, 
but by about DOS 3, DOS was much less likely to be entirely in the bottom 
64K.



At the same time the PC debuted, we were working with early steppings of
the 80186, which did feature two channels of 20-bit address DMA--and 16
bit bus width to boot.


"Wisdom comes from experience. Experience is often a result of lack of 
wisdom."- Terry Pratchett


Although I wanted to know some, I was brought up with NO background in 
hardware nor electronics!

Is it OK to be envious?

My parents were dismayed when I left aerospace FORTRAN programming and 
went into auto repair ("I'll get back into computers when I can afford a 
tabletop computer of my own.  Less than 10 years.")  That started to turn 
around when I was successful, and started supplying them with all of their 
cars.  ("I bought this Karmann Ghia for a few hundred dollars, and did a 
lot of work on it.  I think that you will enjoy it.")


I drooled over S100, and bought the first TRS80 to show up at the store 
($400, since I had learned enough to be able to hook up a tape recorder 
and CCTV monitor).



So, at the time, looking at the 5150, it was an overpriced primitive
implementation using a 1970s CPU.


Even I could see that Segment:Offset was a kludge to get a MB of memory in 
a 64K machine.



Many people at the time thought it
would be less popular than the 5100.


Well, it certainly SOLD way more.  But, I doubt that I could barter it to 
John Titor for a one way ride back 55 years.



Rather than buy my first 5150, I was strongly drawn to the NEC APC. For
about the same price as an outfitted 5150, you could buy a true 16 bit
box with 8" disk drives and really nice graphics that was built like a
battleship.  The only problem is that nobody had ever heard of it.
But IBM had the golden reputation.  Many people at the time,
particularly the older ones, didn't talk about "computers" so much as
"IBM machines".


I made a decision in August, 1981 to buy a 5150.
"It probably won't be as good as many others, but, being from IBM, within 
a decade, most computers will be copies of it, with only a niche market 
for anything else."

I was pleased that Apple survived.

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

Re: Int 13h buffer 64k boundaries

[Jecel Assumpcao Jr. via cctalk]

Chuck Guzis pointed out that the PC was built from 8 bit peripheral
chips, which was where the 64KB problem came from.

When I saw the design, I thought it was really cute how they were able
to use one of the timer channels and one of the DMA channels to
implement a DRAM refresh circuit almost "for free". Steve Jobs made fun
of the design showing that just the CGA board had more chips in it than
the whole Macintosh. Sure, PALs eliminate a lot of chips but so did
6845.
 
Sadly, the PC AT was a lot less elegant. My impression was that they
divided the project among separate groups who weren't perfectly
coordinated. How many different ways does a single computer need to
translate key scan codes to ASCII, for example? And there was a circuit
with a bunch of TTLs just to generate the exact same signal that the
clock chip was already generating. That didn't make sense until you
found it came from an application note about the Multibus - if you have
more than one processor than the signal is no longer the same. This
allowed them to add the MASTER line in the ISA bus which would have been
neat if it actually worked.

-- Jecel

Re: new disassembler vs IDA (was Re: 8085 Dissasembly?)

[Mark J. Blair via cctalk]

> On Apr 19, 2018, at 9:19 AM, Eric Smith via cctalk  
> wrote:
> 
> For the 1802, I've used a really crude disassembler written in C. The 1802
> instruction set isn't very complicated, so a disassembler for it isn't
> either.  It's been so many years since I actually disassembled 1802 code
> that I'm not sure I still have the disassembler around.

Well, you're welcome to use dismantler on CDP1802 code! :)


-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Int 13h buffer 64k boundaries

[Chuck Guzis via cctalk]

On 04/19/2018 12:14 PM, Fred Cisin via cctalk wrote:

> I have no difficulty admitting that I didn't, and don't, have
> Chuck's level of experience and knowledge. My entire venture into
> microcomputers was a hobby that got out of hand.
It's not so much expertise, but where you start your investigations.

Right when I peered into the 5150, I saw the 8237 DMA controller (first
cousin to the 8257) and recognized it from my 8-bit (8085) days.  It was
immediately obvious that IBM had taken a bunch of legacy 8 bit
peripheral chips and shoved them into the PC.   In fact, the 5150 was
surprising in that how primitive the engineering was--something you
didn't expect from a high-tech pioneer like IBM.  So the DMA address
space had to be 16 bits with simple bank select--using a disk controller
chip that was design to be used with 8 inch drives.

The Technical Reference BIOS listing confirmed the suspicion that the
5150 implementation couldn't cross 64K banks.  It had nothing to do with
DOS, per se.

At the same time the PC debuted, we were working with early steppings of
the 80186, which did feature two channels of 20-bit address DMA--and 16
bit bus width to boot.

So, at the time, looking at the 5150, it was an overpriced primitive
implementation using a 1970s CPU.   Many people at the time thought it
would be less popular than the 5100.

Rather than buy my first 5150, I was strongly drawn to the NEC APC. For
about the same price as an outfitted 5150, you could buy a true 16 bit
box with 8" disk drives and really nice graphics that was built like a
battleship.  The only problem is that nobody had ever heard of it.

But IBM had the golden reputation.  Many people at the time,
particularly the older ones, didn't talk about "computers" so much as
"IBM machines".

--Chuck

new disassembler vs IDA (was Re: 8085 Dissasembly?)

[Eric Smith via cctalk]

On Wed, Apr 18, 2018 at 8:17 PM, Mark J. Blair via cctech <
cct...@classiccmp.org> wrote:

> Some of the future reverse engineering projects I have on my to-do list
> involve the CDP1802 processor, which IDA presently doesn't support. When I
> get to them I'll have to decide whether to use dismantler vs. learning how
> to add CDP1802 support to IDA. I'm leaning towards the latter, because IDA
> is so much fancier than dismantler is.


I'd vote for adding it to dismantler.

I had an IDA Pro license at one point, but I seem to have misplaced it, and
it is too old to get me any discount on a new release.  I imagine that IDA
has probably improved a lot since back then, but at the time it had a
pretty awful user interface.

If I had an actual business need to reverse-engineer something using a
processor that IDA supported, I'd certainly buy a new IDA license, but I
wouldn't personally invest any time in building add-ons for expensive
commercial software, when there are open source alternatives that may not
be as good, but are generally good enough.

For the 1802, I've used a really crude disassembler written in C. The 1802
instruction set isn't very complicated, so a disassembler for it isn't
either.  It's been so many years since I actually disassembled 1802 code
that I'm not sure I still have the disassembler around.

what happened to the dec thing with the butterfly discs never heard back I need it for museum thanks cindy ed

[Ed Sharpe via cctalk]

what happened to the dec thing with the butterfly discs never heard back I need 
it for museum thanks cindy    ed

old schematics books

[Electronics Plus via cctalk]

These have now been claimed.

Thanks everybody!

 

Sean I need an address please!

 

Cindy Croxton

Electronics Plus

1613 Water Street

Kerrville, TX 78028

830-370-3239 cell

sa...@elecplus.com

AOL IM elcpls

 



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Re: Intel HEX formats

[Eric Smith via cctalk]

On Thu, Apr 19, 2018 at 1:45 PM, Dennis Boone via cctalk <
cctalk@classiccmp.org> wrote:

>  > Based on what I find in format83.c, this shouldn't be too much
>  > trouble, but I really want to know what "Intel HEX 83" is supposed to
>  > mean.
>
> The easily findable specification document for "intel hex", which has
> intel branding and copyright, is revision A and dated 1988, so perhaps
> "83" is a reference to the original version's year of publication.
>

The format is much older than that, and although it's possible that there
may have been a 1983 edition of that document, it seems more likely that
the author of the software in question chose 83 because that was the format
number that Data I/O assigned for use with their device programmers. Data
I/O refers to it as "Intel Intellec 8/MDS". Here's a list of Data I/O
formats recognized by the UniSite/2900/3900 family programmers:

http://ftp.dataio.com/main/Manuals/UniFam/Translation%20Formats.pdf

Re: Intel HEX formats

[Dennis Boone via cctalk]

 > Based on what I find in format83.c, this shouldn't be too much
 > trouble, but I really want to know what "Intel HEX 83" is supposed to
 > mean.

The easily findable specification document for "intel hex", which has
intel branding and copyright, is revision A and dated 1988, so perhaps
"83" is a reference to the original version's year of publication.

De

Re: Speed now & then

[Peter Corlett via cctalk]

On Wed, Apr 18, 2018 at 06:32:59PM -0600, ben via cctalk wrote:
> On 4/18/2018 4:47 PM, Eric Smith via cctalk wrote:
>> On Tue, Apr 17, 2018 at 8:18 PM, Fred Cisin via cctalk
>>  wrote:
>>> thousands of movies and TV episodes will fit on a 2TB drive. I am anxiously
>>> awaiting higher capacity thin 2.5" SATA.
>> You can get an 8TB drive in 2.5" form factor, but it doesn't contain
>> spinning rust, and it costs around $6000.

alternate.nl, my local boxshifter, is offering a 4TB 2.5" disk for €164.90.
(Whether this price includes the Dutch "you may now pirate all the things"
copyright levy, I don't know.) Sadly, it's both Seagate and shingled-recording.
Okay for backups and similar streaming write-once workloads, but awful as
general-purpose storage.

A common problem with large-capacity 2.5" disks is that they're 15mm high so
don't fit in laptops or similar consumer electronics. 15mm is more of an
enterprise storage standard that has leaked out.

> At one time you could get a $39 aerial up and get free TV like Dr Who..
> Progress seems to be getting rind of the good old and bringing in the $$$.

There's still plenty of free TV out there. Most of it's not even worth what you
paid for it.

[...]
> As for the BBC and other TV networks, we seem to be getting a lot of high
> priced episodes that have like 3 shows per season with a 2 part Christmas
> special mixed in with 90% reality TV.

Given you're quoting prices in dollars, I guess you're talking about the botch
job found on American cable, and the BBC is a rather different beast on its
home turf, where they manage to broadcast more than endless Top Bloody Gear
repeats. In the UK you can just use said cheap UHF aerial to receive it,
although you are supposed to also pay ~£150/year for a TV Licence.

Last call for free old manuals

[Electronics Plus via cctalk]

I have many cases of SAMS facts schematics and other repair manuals for
everything from stereos, tube TVs, ham radios, turntables, etc. Most apply
to equip from the 60s and 70s or maybe a little earlier. Free to a good home
or they go in the recycle bucket tomorrow.

 

Cindy Croxton

Electronics Plus

1613 Water Street

Kerrville, TX 78028

830-370-3239 cell

sa...@elecplus.com

AOL IM elcpls

 



---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Re: Int 13h buffer 64k boundaries

[Fred Cisin via cctalk]

Yes, it was a "beginner" mistake to not already know that the DMA couldn't 
span a 64K boundary.

It is obvious.  Once you've already run into it.

I have no difficulty admitting that I didn't, and don't, have Chuck's 
level of experience and knowledge.

My entire venture into microcomputers was a hobby that got out of hand.



> I'm learning a lot these days that would have been handy back then!
There are numerous people here whose posts present significant 
information.


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


On Wed, 18 Apr 2018, Chuck Guzis via cctalk wrote:


Really?  64K boundary issues cropping up in MS-DOS?

Egad, that would have been known in DOS 1.0.  Certainly, for anyone
writing his/her own low-level disk I/O, it was obvious.

Now, I'll add that if you wrote your own specialized device driver, DOS
did not guarantee handing your driver a buffer that obeyed the 64K
boundary rule.  I suspect that some DOS errors were reported to MS
because of third-party driver bugs.

And if you wrote a low-level driver that used 16-bit I/O, the magic
number was 128K.

But even in the earlies DOS 2.0 device drivers that I wrote, I included
code to split the transfer up to get around the 64K problem if needed.

--Chuck

Intel HEX formats

[David Griffith via cctalk]

I'm trying to understand various hex formats so I can add them as output 
options to minipro[1].  I went looking for existing code to convert binary 
to Intel hex and found repeated copies and references to "format83.c" by 
Erik Lindberg.  It seems to do what I want, but I'm unclear what "Intel 
HEX 83 format" is supposed to mean.  Based on what I see at 
http://www.math.purdue.edu/~wilker/misc/DEVEL/0036/A-6804/BIN2INT.C, this 
program only creates hex files in the I8HEX format, as described in 
https://en.wikipedia.org/wiki/Intel_HEX.


Of course, I'm going to have to support the I16HEX and I32HEX formats too. 
Based on what I find in format83.c, this shouldn't be too much trouble, 
but I really want to know what "Intel HEX 83" is supposed to mean.



[1] https://github.com/vdudouyt/minipro/

--
David Griffith
d...@661.org

A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?

Re: 8085 Dissasembly?

[Liam Proven via cctalk]

On 19 April 2018 at 17:37, Liam Proven  wrote:
>
> I don't know when a word stops being new, but that one is a good 35 years old:
>
> https://en.wikipedia.org/wiki/Heisenbug

(But saying that, I like it, too. Even as a rookie programmer around
the time it was defined, in my trivial programs, I'd seen them.)

-- 
Liam Proven • Profile: https://about.me/liamproven
Email: lpro...@cix.co.uk • Google Mail/Hangouts/Plus: lpro...@gmail.com
Twitter/Facebook/Flickr: lproven • Skype/LinkedIn: liamproven
UK: +44 7939-087884 • ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053

Re: 8085 Dissasembly?

[Liam Proven via cctalk]

On 19 April 2018 at 13:27, Noel Chiappa via cctalk
 wrote:
> > From: Charles Anthony
>
> > discovered that changing the executable would change the behavior -- a
> > heisenbug.
>
> Ooh, love that neologism.

I don't know when a word stops being new, but that one is a good 35 years old:

https://en.wikipedia.org/wiki/Heisenbug

-- 
Liam Proven • Profile: https://about.me/liamproven
Email: lpro...@cix.co.uk • Google Mail/Hangouts/Plus: lpro...@gmail.com
Twitter/Facebook/Flickr: lproven • Skype/LinkedIn: liamproven
UK: +44 7939-087884 • ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053

Re: TRS-80 bits

[Jim Brain via cctalk]

On 4/19/2018 2:54 AM, Wouter de Waal via cctech wrote:

Hi all

I have a TRS-80 Model 2000 B/W Graphics board and a TRS-80 Card Cage 
kit (upgrade model 12 to model 16B)


Are either of these worth shipping from the antipodes to anyone?

W

Hmm, I guess it does indeed depend on shipping costs, but I am looking 
for a card cage for the 12, and they can be a bit tough to find.



Feel free to contact me off list, I live in Iowa, USA

--
Jim Brain
br...@jbrain.com
www.jbrain.com

FYI: IBM System/34 available in Boston, MA

[Chuck Guzis via cctalk]

Just noticed this post on the Vintage Computer forum.  I don't know a
thing about it:

http://www.vcfed.org/forum/showthread.php?63253-IBM-System-34-5340

--Chuck

Re: 8085 Dissasembly?

[Noel Chiappa via cctalk]

> From: Charles Anthony

> discovered that changing the executable would change the behavior -- a
> heisenbug.

Ooh, love that neologism.

Noel

TRS-80 bits

[Wouter de Waal via cctalk]

Hi all

I have a TRS-80 Model 2000 B/W Graphics board and a TRS-80 Card Cage 
kit (upgrade model 12 to model 16B)


Are either of these worth shipping from the antipodes to anyone?

W

Absolute OpenBSD book

[mark--- via cctalk]

This is available for the cost of postage.

 

https://photos.app.goo.gl/OpVKxtbXqKp2VPl52

 

Mark.