On Tue, Jun 16, 2015 at 12:20 AM, tony duell a...@p850ug1.demon.co.uk wrote:
[My 11/730]
Sorry to hear that it's been decabled. Take your time to route those cables
through the bottom pan properly,
Yes, it's going to be a lot of work to get it back together.
I think I am going to start
On Jun 16, 2015, at 06:46, tony duell a...@p850ug1.demon.co.uk wrote:
Again, I wonder if the data retention time decreases as the number of bits
per device increases. Intuitively it should. Mind you, any SD card is probably
going to be more reliable than a real TU58 tape now :-)
I think
On 06/15/2015 09:58 PM, Zane Healy wrote:
Does anyone happen to know what sort of computers Fairchild would have been
using in the late 60's for design work?
Fairchild, even in the 60s had many divisions. Which one are you
thinking of? (Not that I can provide an answer...)
--Chuck
Sure, the pre-manufactured boards can allow you to prototype quickly... but
I think Tony is kind of bemoaning the loss of the old way and I respect
that ... I kind of miss it myself, even though I wasn't there to experience
it first-hand ...
It's also that this is the 'classic computers'
Maybe Univac?
On 6/15/2015 9:58 PM, Zane Healy wrote:
Does anyone happen to know what sort of computers Fairchild would have been
using in the late 60's for design work?
Zane
--
The contents of this e-mail and any attachments are intended solely for the use
of the named
I am of course counting all the transistors inside that chip.
Well, that was obvious. But it raises an interesting point, today you
can cram a whole computer in the footprint of the simplest DIP carrier.
For the same price point and same reliablity. Is it then overkill if you
choose to
Choosing the larger card is, IMO, the right answer because you don't
actually waste the space, you extend the life significantly because the
wear leveling will spread your 256K across the entire flash region.
The larger that region, the less often you re-write the same cells,
thereby extending
From: tony duell
One method that works for me is that if you are buying a fairly cheap
part, buy 10 of them and put the rest in stock. Or more than 10 if it
is something really common.
I suspect a lot of us do that - that's why I have tubes of 4164's, etc, for
instance. It
On Jun 16, 2015, at 07:36, Chris Elmquist chr...@pobox.com wrote:
So, now you have to use a Type A to Type A cable to connect this box to
your computer.
That is just really, really messed up and I honestly tried to make it
right but it was like pushing a rope.
I hope my friends will
As long as we're talking philosophy, what do y'all think about emulating the
TU58 drive, vs. emulating the TU58 *tape*?
I cannot properly express my opinion of that tape cartridge design even if I
violate list rules about use of profanity. But the drive itself isn't all that
bad, aside from
On Tue, Jun 16, 2015 at 04:18:03PM +, tony duell wrote:
[Build your own 11/70]
Oh, very much! Then we could have a discussion about using
modern switching power supplies ot not ;-)
As opposed to the original 11/70 switching supply?
I would suspect that modern switchers are more
On Jun 15, 2015, at 9:21 PM, ben bfranc...@jetnet.ab.ca wrote:
On 6/15/2015 7:11 PM, Paul Koning wrote:
On Jun 15, 2015, at 8:09 PM, ben bfranc...@jetnet.ab.ca wrote:
On 6/15/2015 4:42 PM, Toby Thain wrote:
I think Tanenbaum should be fine? A lot of it is fairly
timeless.
The
On Jun 16, 2015, at 08:19, geneb ge...@deltasoft.com wrote:
On Tue, 16 Jun 2015, Noel Chiappa wrote:
I wish there was some _easy_ way to lay in a stock of the most common TTL
IC's - e.g. some kind of kit one could buy - but alas, I don't know of any.
(Hence my dream of finding and
Again, I wonder if the data retention time decreases as the number of bits
per device increases. Intuitively it should. Mind you, any SD card is
probably
going to be more reliable than a real TU58 tape now :-)
I think that paper tape, used outdoors on a rainy day, is likely to be more
reliable
On Tuesday (06/16/2015 at 07:24AM -0700), Mark J. Blair wrote:
On Jun 16, 2015, at 06:46, tony duell a...@p850ug1.demon.co.uk wrote:
Again, I wonder if the data retention time decreases as the number of bits
per device increases. Intuitively it should. Mind you, any SD card is
On Tuesday (06/16/2015 at 07:43AM -0700), Mark J. Blair wrote:
On Jun 16, 2015, at 07:36, Chris Elmquist chr...@pobox.com wrote:
So, now you have to use a Type A to Type A cable to connect this box to
your computer.
That is just really, really messed up and I honestly tried to make it
On Tue, 16 Jun 2015, Mark J. Blair wrote:
On Jun 16, 2015, at 08:19, geneb ge...@deltasoft.com wrote:
On Tue, 16 Jun 2015, Noel Chiappa wrote:
I wish there was some _easy_ way to lay in a stock of the most common TTL
IC's - e.g. some kind of kit one could buy - but alas, I don't know of
On Tue, Jun 16, 2015 at 01:54:56PM +, tony duell wrote:
I find it odd that people want to have a lights-and-switches panel, but are
prepared to totally
adulterate the hardware of the machine that drives it.
Are you honestly suggesting that I should rebuild a PDP-11/70
from things I
On Jun 16, 2015, at 2:49 AM, ben bfranc...@jetnet.ab.ca wrote:
...
Since the computer I designed is a *small* computer, 8 16 bit operating
systems is what I am looking at for ideas. This is a 18 bit cpu with the
concept, byte access of memory needs true 18 bit addressing
and 16 bits
I find it odd that people want to have a lights-and-switches panel, but are
prepared to totally
adulterate the hardware of the machine that drives it.
Are you honestly suggesting that I should rebuild a PDP-11/70
from things I have in my partsbin?
You have to admit it would be an
On Tue, Jun 16, 2015 at 03:58:51PM +, tony duell wrote:
Are you honestly suggesting that I should rebuild a PDP-11/70
from things I have in my partsbin?
You have to admit it would be an interesting and educational
project :-)
Oh, very much! Then we could have a discussion about using
On Monday (06/15/2015 at 10:14PM -0700), Mark J. Blair wrote:
On Jun 15, 2015, at 21:59, tony duell a...@p850ug1.demon.co.uk wrote:
Even though there are at least 4 different USB connectors
Ok, you got me there! When I was working for a GPS startup, I used mini-B on
everything I
As long as we're talking philosophy, what do y'all think about emulating the
TU58 drive, vs. emulating the TU58 *tape*?
I cannot properly express my opinion of that tape cartridge design even if I
violate list rules about use of
profanity. But the drive itself isn't all that bad,
It's also that this is the 'classic computers' list. To me, classic
computing means
rather more than just the hardware. It also covers the design and
construction methods, technology and so on. And there seems to be
precious little of that in a modern microcontroller acting as a clock
When repairing machines it is some times hard to find the data sheet for a
particular component.
Sometimes google hasn't been able to find the the data sheet for me.
My father worked in the electronics business for his entire career and kept
a lot of the data books that he received.
I have
On Jun 15, 2015, at 7:10 PM, Sean Caron sca...@umich.edu wrote:
...
4. Madnick/Donovan Operating Systems or Donovan's Systems Programming ...
were, I imagine, the canon of the 70s and early 80s ... these are written
mostly with the S/360 in mind …
If it’s written with 360 operating
On Tue, 16 Jun 2015, Noel Chiappa wrote:
I wish there was some _easy_ way to lay in a stock of the most common TTL
IC's - e.g. some kind of kit one could buy - but alas, I don't know of any.
(Hence my dream of finding and acquiring someone else's collection! :-)
Suggestions for the source of
On 6/16/2015 8:56 AM, Paul Koning wrote:
On Jun 16, 2015, at 2:49 AM, ben bfranc...@jetnet.ab.ca wrote:
...
Since the computer I designed is a *small* computer, 8 16 bit
operating systems is what I am looking at for ideas. This is a 18
bit cpu with the concept, byte access of memory needs
That seems to me like it would be the trickiest part. The TU58 schematic
appears to indicate that there are
I think so. Of course you could cheat by making it a read-only tape. But I
don't like that.
separate erase head gaps (not on a separate head like in audio cassette
drives), so
On Jun 16, 2015, at 12:10 PM, tony duell a...@p850ug1.demon.co.uk wrote:
As long as we're talking philosophy, what do y'all think about emulating the
TU58 drive, vs. emulating the TU58 *tape*?
I cannot properly express my opinion of that tape cartridge design even if I
violate list
On Jun 16, 2015, at 09:10 , tony duell a...@p850ug1.demon.co.uk wrote:
You would, of course, not know which track it was reading, so you would have
to output 2 blocks, one on
each track, at once. And how would you detect it was writing? Look for an
extra signal at the coupling head
or
And yet another (possibly the most common one on computers) is to have a
small drive wheel that pulls the tape at constant speed across the
heads, and then have some other construction that drives the tape reels
depending on tape tension or length. Think vacuum columns or spring
loaded arms.
On 2015-06-16 19:51, tony duell wrote:
And yet another (possibly the most common one on computers) is to have a
small drive wheel that pulls the tape at constant speed across the
heads, and then have some other construction that drives the tape reels
depending on tape tension or length. Think
On 06/16/2015 11:08 AM, Henk Gooijen wrote:
The round (approx 2 diameter) bearings of the TU80 do not rotate.
Instead, the metal has tiny holes. Air pressure pushes the tape away
from the bearings. As the tape moves, due to movement pressure, the
tape comes closer to the air bearing. That is
On 06/16/2015 11:22 AM, Johnny Billquist wrote:
Uh... The TU80/TU81 do not have vacuum columns...
I didn't say that they did, Johnny. I said that the TU80 hails back to
the vacuum-column CDC drive design of the 1960s. At least that's my
understanding.
--Chuck
On 6/16/2015 9:58 AM, Pontus Pihlgren wrote:
On Tue, Jun 16, 2015 at 01:54:56PM +, tony duell wrote:
I find it odd that people want to have a lights-and-switches panel, but are
prepared to totally
adulterate the hardware of the machine that drives it.
Are you honestly suggesting that I
On 2015-06-16 18:21, Paul Koning wrote:
On Jun 16, 2015, at 12:10 PM, tony duell a...@p850ug1.demon.co.uk wrote:
As long as we're talking philosophy, what do y'all think about emulating the TU58
drive, vs. emulating the TU58 *tape*?
I cannot properly express my opinion of that tape
-Oorspronkelijk bericht-
From: Johnny Billquist
Sent: Tuesday, June 16, 2015 7:31 PM
To: cctalk@classiccmp.org
Subject: Re: On the Emulation of TU58s
[... snip ...]
And then we have drives like the TU80/TU81 which do not seem to fit into
any of the mentioned categories. I'm not
On 2015-06-16 20:23, Mark J. Blair wrote:
On Jun 16, 2015, at 11:22 , Johnny Billquist b...@update.uu.se wrote:
Pretty much the standard CDC vacuum-column design since the 1960s. The
TU80 is, after all, a CDC product. Two counter-rotating capstans--tape
movement is determined by applying
On Jun 16, 2015, at 11:22 , Johnny Billquist b...@update.uu.se wrote:
Pretty much the standard CDC vacuum-column design since the 1960s. The
TU80 is, after all, a CDC product. Two counter-rotating capstans--tape
movement is determined by applying positive or negative pressure to
ether or
Mark, I've thought of that for my HP 9845, too. Sure would be nice to
fabricate something that's flexible hardware that can be programmed for the
peculiarities of various implementations. I'll put it on my list of things
to do once I'm done with my dissertation. :-)
On Tue, Jun 16, 2015 at
[Driving tape]
Another solution is to avoid the problem entirely by not requiring constant
linear speed. That’s what DECtape
(the real one) does.
Sure. A number of tape drives were built that way, the HP9865 (and thus the
built-in tape drive on the
HP9830) is another example.
One is
On 2015-06-16 20:20, Chuck Guzis wrote:
On 06/16/2015 11:08 AM, Henk Gooijen wrote:
The round (approx 2 diameter) bearings of the TU80 do not rotate.
Instead, the metal has tiny holes. Air pressure pushes the tape away
from the bearings. As the tape moves, due to movement pressure, the
tape
On 06/16/2015 01:54 PM, Brent Hilpert wrote:
Once ran across a Honeywell drive (7-track) that had a 'vacuum
capstan'. The capstan wheel had a vacuum path through the axle and
then transferred the vacuum out to holes around the perimeter. So
rather than a pinch roller or rubber frictional
-Oorspronkelijk bericht-
From: Johnny Billquist
Sent: Tuesday, June 16, 2015 8:22 PM
To: cctalk@classiccmp.org
Subject: Re: On the Emulation of TU58s
On 2015-06-16 20:20, Chuck Guzis wrote:
On 06/16/2015 11:08 AM, Henk Gooijen wrote:
The round (approx 2 diameter) bearings of the
On 2015-06-16 21:20, tony duell wrote:
And yet another (possibly the most common one on computers) is to have a
small drive wheel that pulls the tape at constant speed across the
heads, and then have some other construction that drives the tape reels
depending on tape tension or length. Think
On Tue, 16 Jun 2015, tony duell wrote:
Actually, IIRC a USB A male-female cable violates the spec...
The spec forbids extending the cable further?
Or should the spec forbid absolutely any cable,
with absolutely any USB connector on either end?
Mine too! I just love the old paper books versus PDFs ... and I've got a
pretty decent collection of databooks both that I have picked up second
hand, as well as a pretty large chunk of those that my dad acquired over
the course of his engineering career when he was cleaning them out from his
On 6/16/2015 12:01 PM, Sean Caron wrote:
Mine too! I just love the old paper books versus PDFs ... and I've got a
pretty decent collection of databooks both that I have picked up second
hand, as well as a pretty large chunk of those that my dad acquired over
the course of his engineering career
On 2015-Jun-16, at 12:31 PM, Paul Koning wrote:
On Jun 16, 2015, at 3:20 PM, tony duell a...@p850ug1.demon.co.uk wrote:
...
The actual tape movement as such, is all done by the small wheel next to
the head, which just runs the tape past the head.
Which is essentailly the same as the capstan
On Jun 16, 2015, at 09:10 , tony duell a...@p850ug1.demon.co.uk wrote:
Incidentally, given the fact that a constant motor speed - constant tape
speed, it should be possible to
make a device to put the timing track on a blank tape for the TU58. Has
anyone done that?
There's no timing
At 12:30 PM 6/16/2015, Mattis Lind wrote:
I have compiled a list of them, mostly for my self, so that I somewhat easier
would find what I look for.
That is a nice list, and includes many that are not among my ~80 (which does
not include my ~60 vacuum tube manuals). Could you post the original
And yet another (possibly the most common one on computers) is to have a
small drive wheel that pulls the tape at constant speed across the
heads, and then have some other construction that drives the tape reels
depending on tape tension or length. Think vacuum columns or spring
loaded
Johnny Billquist wrote:
Then you can figure out tape speed across the
heads (if you care) by just observing flux changes.
Tony Duell wrote:
Only if there is something on the tape. These computer tape drives could
surely record on a
totally blank tape and get the right number of bits per
On 06/16/2015 11:30 AM, Henk Gooijen wrote:
well, the tiny space between the tape and the air bearing could
be regarded a vacuum column, but it's a very short one :-)
The two air bearings are immediately above and below the R/W
and erase head. And they do *not* rotate. The tape glides on
an air
On Jun 16, 2015, at 3:20 PM, tony duell a...@p850ug1.demon.co.uk wrote:
...
The actual tape movement as such, is all done by the small wheel next to
the head, which just runs the tape past the head.
Which is essentailly the same as the capstan in an audio tape recorder,
albeit the
On Jun 16, 2015, at 12:46 , tony duell a...@p850ug1.demon.co.uk wrote:
For something even madder, look at the design of the original Radio Shack
'Line Printer' which was
actually a Centronics something-pr-other (733?). This thing (which is not a
line printer at all) has a belt
running
On Jun 16, 2015, at 4:05 PM, Kyle Owen kylevo...@gmail.com wrote:
On Jun 16, 2015 3:43 PM, tony duell a...@p850ug1.demon.co.uk wrote:
Actually, no. That honour goes to the PSU in a Zenith MDA monitor
which as I said 'combines the efficiency of a linear with the reliability
of a
On Wed, Jun 17, 2015 at 1:54 AM, tony duell a...@p850ug1.demon.co.uk wrote:
It's also that this is the 'classic computers' list. To me, classic computing
means rather
more than just the hardware. It also covers the design and construction
methods, technology
and so on.
DING.
Staying
On Jun 16, 2015, at 3:48 PM, Eric Smith space...@gmail.com wrote:
Johnny Billquist wrote:
Then you can figure out tape speed across the
heads (if you care) by just observing flux changes.
Tony Duell wrote:
Only if there is something on the tape. These computer tape drives could
surely
On Jun 16, 2015, at 17:52 , Mike Ross tmfdm...@gmail.com wrote:
'remanufacturing' has become part of preservation movements in
general;
[...]
Has this ever been seriously considered, or mooted as a possible
co-operative venture for a group of us?
On this topic, I'm particularly curious
I am humbled (yes, it is possible!) got a very nice email from
Homebrew Computer Club moderator / SOL-20 co-developer / Osborne 1 chief
engineer (and many more):
This book presents the history of personal, portable computing from the
abacus to the present day in a remarkably thorough,
Mine too! I just love the old paper books versus PDFs ... and I've got a
So do I. It is a lot easier to filp through a databook than through a collection
of PDFs.
This has 2 uses :
1) If you need to find what a house-numbered part really is, you can quickly
look at possible candidates in
Date: Mon, 15 Jun 2015 19:42:42 -0400
From: Michael Thompson michael.99.thomp...@gmail.com
To: cctech cct...@classiccmp.org
The M452 creates a 220 Hz clock for the TTY transmitter and a 880 Hz clock
for the TTY receiver.
The M405 for the DP12-B serial port generated a clock that is 16x the
[M452]
that the original appears to use a 2k 10-turn pot, and a 7440 output buffer,
neither of which are in my rather extensive junk box.
In fact the 7440 are rather rare, and I see the cheapest I can get them for
is around $4.00 each.
True. But you don't need either to build and test the
The M452 creates a 110 Hz clock for the TTY transmitter and a 880 Hz clock
for the TTY receiver.
Does it? The prints I have show the 2 outputs with a factor of 4 (not 8) in
frequency.
The M405 for the DP12-B serial port generated a clock that is 16x the baud
rate which is then divided by
I thought I'd take a quick spin through the operating systems section of my
library now that I'm at home just to give you some titles that you might
want to check out.
1. Toby mentions Tanenbaum's Minix book and that's a fairly canonical text
... there is a lot of great information in there but
Date: Mon, 15 Jun 2015 05:01:36 +
From: tony duell a...@p850ug1.demon.co.uk
Subject: RE: PDP-12 Restoration at the RICM (tony duell)
Tony, thank you for your offer to supply replacement M452 Variable Clock
modules for the console. We already have one jumpered for 110 baud for
the
On 6/15/2015 5:10 PM, Sean Caron wrote:
I thought I'd take a quick spin through the operating systems section of my
library now that I'm at home just to give you some titles that you might
want to check out.
1. Toby mentions Tanenbaum's Minix book and that's a fairly canonical text
... there is
On Tue, Jun 16, 2015 at 04:32:23AM +, tony duell wrote:
Oh come on. You yourself said you are here to learn. This module
is hardly complicatated.
Well, you got me there :)
/P
On Tue, Jun 16, 2015 at 04:28:16AM +, tony duell wrote:
I am of course counting all the transistors inside that chip.
Well, that was obvious. But it raises an interesting point, today you
can cram a whole computer in the footprint of the simplest DIP carrier.
For the same price point and
In my efforts to understand the problem with the Cache/TB Diagnostics I
tried to run it under 11/750 simulator in SimH. It fails too!
ECKAL -- VAX 11/750 Cache/TB Diagnostic
HALT instruction, PC: 2608 (MTPR #F,#26)
Although not the same location.
On the real machine:
@?ECKAL -- VAX 11/750
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