I have a VT525 that I couldn't turn off. I took it apart and there's
an adapter that connects the metal rod off the button on the front to
the power switch inside. The adapter has crumbled and it feels like
it was wax but it may have just been some plastic that has severely
deteriorated.
Before I try to work up some kind of replacement, has anyone already
designed a 3D-printed replacement? I don't have a 3D printer but do
have a friend that could print one for me. Otherwise, I'll see if I
can come up with something.
--
Eric Dittman
Hello,
I have a question about 9 track tapes and block sizes.
What I know is that tape is subdivided in files by means of marks, and each
file is subdivided in blocks of equal size.
Programs like tar use a specific block size to create files on tape.
However files can have different block sizes like bootloader file,
installation dumps and root file system copy on 2.11BSD.
Now suppose you find and unknown tape you want to preserve: using dd you
could easily 1:1 copy tape files to hard disk files using a SCSI drive and
Linux.
But: how you know which block size is on the tape?
Thanks
Andrea
All,
I've been delving into ancient IBM PC-DOS... 1.0, 2.0 and have landed on
2.10 as the experience I'm going to hang out with for a while. It's
stable in QEMU and 86Box and I am able to run MASM 1.0, 2.0 and Pascal
1.0 and 2.0.
86Box is more true to old-school boxes, but qemu runs on my Mac, so I
like using Qemu. But, Pascal seems to prefer 86Box, it prints weird
characters in qemu w/writeln(), which is annoying, but I'm doing more
assembly and BASIC at this point, so Qemu's emulation is sufficient.
What I've got working:
IBM PC-DOS 2.10 - seems to be working fine in both (installed to fixed disk)
IBM Macro Assembler 1.0 and 2.0 - seems to be working fine in both
(installed to fixed disk)
IBM Pascal 1.0 and 2.0 - hokey in both, tricky about the floppy being
present, regardless of debug fix, and doesn't like QEMU.
QEdit 2.1 - works great in both (installed to fixed disk)
I found some good books on BASIC, Pascal, and Assembly:
Albrecht, 1990. Teach Yourself GWBASIC. (covers later BASICA sufficiently)
Pardee, 1984. The Waite Group Pascal Primer for the IBM PC. (Great book)
Metcalf and Sugiyama, 1985. Compute!'s Beginner's Guide to Machine
Language on the IBM PC & PCjr. (Excellent book)
Lafore, 1984. The Waite Group Assembly Language Primer for the IBM PC &
XT. (Wordy, but good)
Pretty much everything I've programmed works fine. Graphics stuff is
better in 86Box where I can control the monitor that's attached, but no
complaints.
Some questions I have related to the exploration:
1. I'm curious if there are other folks out there doing similar stuff?
2. Most of the Assembly examples use DOS interrupt 21 for output. Is
this typical of assembly programs of the time, or did folks use other
methods?
3. I was able to find a lot of 5150/5160 and other manuals, but I
couldn't find an IBM Macro Assembler 2.0 manual (there are plenty of IBM
Macro Assembler/2 manuals, but those are for OS/2, not DOS). Does anyone
know where I can find one online?
4. In y'all's view, what are the significant differences between IBM
PC-DOS 2.10 and it's brother MS-DOS 2.x?
5. I'm thinking of moving on to 3.3 at some point, in your view, what
are the advantages?
6. I'm happy to post here, but if y'all know of a more appropriate
venue, please suggest it?
Thanks,
Will
--
GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF
> From: Chris Hanson
> There's an MXV11-B (M7195) on its way to me. :)
Wow, you've got a really good fairy god-mother!
I've been trying to buy one on eBait for some time now (in part to have one
to take a photo of for the CHWiki), and no luck - they always get bid up into
the sky. And here someone has one for you!
Life is unfair!
Noel
The making of this computer? perhaps explain why I never had someone wander in and talk about designing or building a MOTOROLA MINICOMPUTER ....Ed#
On Monday, October 5, 2020 Bill Degnan via cctalk <billdegnan at gmail.com; cctalk at classiccmp.org> wrote:
On Mon, Oct 5, 2020 at 1:10 PM Al Kossow via cctalk <cctalk at classiccmp.org>
wrote:
> On 10/4/20 11:13 PM, Josh Dersch via cctalk wrote:
>
> > Just made a minor breakthrough; a random usenet post suggested that the
> > MDP-1000 was just a rebadged General Automation SPC-12, and so it is.? I
> > suspect the internals of the unit I have (which is badged as an
> "MDP-6650"
> > on the rear) are a bit different than either the MDP-1000 or the SPC-12
> > (and I'm no closer to finding answers to my IC identification questions),
> > but it at least gives me another avenue to explore...
> >
> > (Bitsavers has a few items:
> > http://bitsavers.org/pdf/generalAutomation/spc12/)
>
> https://www.computerhistory.org/collections/search/?s=spc-12
Is this a case of not being able to find the correct TI or Motorola IC
guide or is there something unique / OEM about this one?? I do have some
late 60's early 70's IC guides of these manufacturers that I can check,
original bound paper copies.? Please advise.
Bill
More mysteries while poking at the MDP-1000. Spent some time this evening
working out the rest of the signals on the power harness (I suspect inputs
for an LTC circuit and a "power good" signal, as well as something
connected to a relay on the backplane, probably related to power control).
There are a lot of unidentifiable ICs on the main CPU logic board and on
the backplane, mixed in with bog-standard 7400-series TTL. Curious if
anyone has any ideas, as my searches and perusal of datasheets/databooks on
Bitsavers have turned up nothing. These are all TI-manufactured ICs, 1969
manufacturing dates, with "SN48xx" and "SN63xx" part numbers (a few omit
the "SN" prefix.) I'm wondering if these are just standard 7400 ICs with
special codes; for example there are several SN4816's near the edge
connector for the I/O bus, where a 7416 might (?) make sense, and from some
basic probing and following traces I think the pinouts make sense.
(Everything's conformal coated so it's a real bear to beep things out...)
Any ideas?
Thanks again,
Josh
5.25" SMD drives
From: David C. Jenner <djenner_at_earthlink.net>
Date: Tue Jun 24 19:28:00 2003
I have complete docs (User's Manual and Reference Manual, both
very long) for both of the Seagate drives (the manuals cover
both). And a stock of the 1.2GB drives, including power supply
and cables. And QD33 Qbus adapters. I'll be glad to entertain
offers for these offline, especially trades for PDP-11 equipment.
Dave
---
wonder if
- he is still on the list
- still has the manuals
Dear Tom,
Does your Sun workstation is functional and read QIC -150 cartridge?
I have some old 3M 6150 cartridges that was created by Sun Sparc workstation in 2000.
One those cartridges, I have some my personal files I like to get them.
If you can you read those cartridges, I can pay some money for you?
Chen Tsay
Greetings everyone, it's Been a while since i posted here.
I had picked up some modcomp minicomputers over the past couple years. A
modcomp classic, with a nice front panel with binary swiches, similar to a
pdp 11. There is a modcomp 32 as well, the machine boots from internal
floppy drives.
I was eager to pick up these machines, and save them from being thrown out.
I picked up all of the documentation as well. Everything. A truckload of os
information. I started to scan it all, but about 3/4 of the way through, my
scanner broke.
The 32 machine was not stored in climate controlled conditions before i
picked it up, and is a bit more worn. It is designed to boot off floppys to
load the microcode into the cpu... but the floppys... id be supprised if
anything survived. Stored in bad conditions.
The classic has internal microcode roms and will not have the same
troublesome problem.
I have been unable to devote the time and space to these machines as i had
planned. I have been far too busy working at ibm, i am planning to shut
down my side interests and focus on my dec pdp 11 stuff and ibm mainframe.
I am looking to see if anyone would be interested in buying these. I spent
a great deal getting them moved and keeping them in cool climate controlled
storage, i am looking to see if i can get any offers and break even.
Keep in mind, they are the size of a computer rack and heavy.
I will post back with pictures soon.
> From: Chris Hanson
> My little LSI-11 system doesn't have a usable Line-Time Clock because
> it lacks the register, which it expects to be in either an MXV11-B
> (M7195) or a BDV11 (M8012). My power supply theoretically supplies the
> LTC .. so my preference would be an M7195 ...
> Does anyone have one they'd be interested in parting with?
The MXV11-B is rare and expensive - I think because it's a Q22 card. The
BDV11 is, on the other hand, fairly common, not not too expensive. If you
can't find a reasonably-priced one (i.e. <US$50) one on eBait, Paul Anderson
used to have some. If he's out, I can probably be convinced to part with one.
The BDV11 has on Q18 _terminator_ functionality; there's an ECO to make that
Q22,though.
FWIW, both the KDF11-B and KDJ11-A have built in LTC's, if a CPU
upgrade is feasible for you.
Noel
Last year I found a box of material, much of it related to S-100
computers and the Sol I owned in the 1970s. I've scanned it in and
posted it to the Internet Archive:
https://archive.org/details/@j_peterson
Folks researching obscure old devices (Biotech Electronics CGS-808,
anyone?) may find something useful. I still have a few documents
waiting to scan, but this is 98% of it.
Cheers,
jp
I am helping a friend with his IBM 3279 terminal. I got the PSU working
after reverse engineering it. Concluded that the SMPS control chip was a
standard TDA 2640 in IBM disguise.
But of course the thing didn't work with the PSU fixed. A fuse which was in
series with the vertical deflection coil on the analogue board went toast
together with a 200 ohm resistor in the vertical deflection circuit.
https://i.imgur.com/O4YEsdL.jpg
At first I thought this had to do with some kind of fault in the vertical
deflection coil itself. It measured only 1.2 ohms. But checking the IBM MAP
manual revealed that both deflection yokes are supposed to be less than 2
ohms.
So there has to be something else. I powered up the analogue board with the
5V and 8.5V that is normally supplied by the PSU (left the 103V unconnected
since it used for the HV mostly) just to see what happened. The power
consumption was reasonable, 0.3 amps on the 5V and 0.16A on the 8.5V.
I then probed around among all those annoying IBM marked chips and square
aluminium boxes. I found one chip that had 250 kHz on a pin. The chip
appeared to be a divider since there were also 125 kHz, 62 Khz 31 kHz and
15 kHz. It seems to be originating from a square aluminium box. And then I
found a signal which was around 20 Hz on another chip.
As far as I understand the 15 kHz would fit well with the 64us sweep in the
manual.
But what is the purpose of the 20Hz signal? Vertical deflection?
http://bitsavers.trailing-edge.com/pdf/ibm/3279/SY33-0069-3_3279_Color_Disp…
According to the above manual the frame sync is 10 ms for model 2 and 13.8
ms for model 3 (this is a model 3).
And moreover if 20Hz is the frequency used for generating the vertical it
could explain why the fuse blew since the current in the deflection yoke
should normally increase linearly with time. Three times longer deflection
period would yield a three time higher current, thus very likely to exceed
the 1.5A rating of the fuse.
So I am looking for either another analogue board for an IBM 3279 or a
schematic for the thing or maybe both would be great. IBM stuff is
annoyingly hard to repair...
Has anyone seen schematics for the IBM 3279? Does anyone have a spare
analogue board?
/Mattis
> From: Chris Zach
> Might have an older MXV11 as well, could the 18 bit one do this
Ooh, good catch; yes, the MXV11-A also has an LTC. I too have an 'extra' one.
The OP should probably check to see if his P/S generates the bus clock signal;
most of the options we've discussed for him would need it.
Noel
My little LSI-11 system doesn't have a usable Line-Time Clock because it lacks the register, which it expects to be in either an MXV11-B (M7195) or a BDV11 (M8012). My power supply theoretically supplies the LTC but I haven't confirmed that, so my preference would be an M7195 if possible.
Does anyone have one they'd be interested in parting with? I'm fine with shipping internationally and with paying a reasonable price, and I promise to take good care of it and pass it on to another good home if I should ever part with it. (Friends don't let friends recycle rare electronics.)
Alternately, is there a "modern" Q-bus board that provides things like LTC (both the clock and the register), SLU, memory, etc.?
-- Chris
I'm researching Multiuser DOS out of my own interest. A version made by Concurrent Controls specifically. However, I have been unable to find documentation on it to satisfy my curiosity on how it works and how it is configured. They must have somehow broken the 640K barrier or virtualized each user session, I'd like to understand it better. What were it's limitations, I'm guessing that each user didn't get direct access to hardware. Anyone out there have a document or experience with it?
Thanks,
Jonathan
Hi all,
Does anyone happen to know the value of C13 in a Compaq Portable II power
supply? It's a small-ish tantalum that lives next to the heatsink between
U6 and U7 - although mine doesn't live any more, having just roasted itself
in spectacular fashion.
Quite possibly there's some other fault at play, but on the other hand it
may have just been its time; tantalums in vintage stuff seem a little prone
to failure.
cheers
Jules
Manx lists MP-01394-00 as the Field Maintenance Print Set for the DEC
Professional 350. I can't find this online and I was wondering if anyone has
a scan of it by any chance?
Thanks
Rob
Hello,
I'm making a software emulator for the General Turtle TT2500. Does
anyone have any information about it? It's hard to come by.
Here's what I have learned:
It's a custom TTL design by Marvin Minsky et al, with 64K 16-bit memory
and 4K 16-bit control store. It has two displays attached, one for
vector graphics, and one for text. There is a UART for talking to a
host (presumably running Logo), and a keyboard.
Thanks for putting this out. Not a system I'm familiar with but did
play around briefly with APL in 1969 on an IBM 360.
Very nice emulator and managed to get it up and running once found an
emulated HP graphics terminal. Pleasantly surprised that emulator
CPU useage was very small (unlike BasiliskII which runs one CPU core
at 100% when I run my old Mac programs) and played adventure came
that came with it. Last time I played an adventure game of that
nature was in 1981 and remember thinking how neat it was back then.
>As some people here are aware, I have spent probably too much time this summer
>hacking on J. David Bryan's excellent Classic HP 3000 simulator and trying to
>build up the ultimate classic 1980s HP 3000 system (virtually speaking).
>
>I started with the MPE V/R KIT that's widely available and expanded
>that into a
>5x120MB HP 7925 disc system and configured things like the system directory
>size and all the system tables to make a fully functional multi-user server.
>
>I then set about collecting as much old MPE software as I could find, which
>included Keven Miller's collection of the old Contributed Software
>Library tapes
>which were conveniently available in SIMH format. This is a huge trove of cool
>stuff including most of the classic mini/mainframe games (Dungeon, Warp,
>Advent, etc., etc.) and even a little game called DRAGONS that was written in
>1980 by a guy named Bruce Nesmith when he was in college and he used it
>to get a job at TSR and went on to write parts of many classic D&D products
>and eventually landed at Bethesda where among other things he was the
>lead designer for another little game called The Elder Scrolls V:
>Skyrim. I was
>able to track Bruce down and give him a copy of the system with his 40 year
>old game running on it. The CSL tapes also include other amazing goodies
>that people developed and gave away over the years, including a FORTH and
>LISP, as well as most of the system and utility programs that people used to
>run their 3000 shops. It's quite fun to explore.
>
>I was curious how far we could push the 3000 simulator, so I hacked all
>the memory bank registers to be six bits instead of four bits, and we
>now have a simulated HP 3000 Series III that supports 8MB of memory, 4x
>more than any physical system ever did. I started trying to do the same thing
>for giant disc drives, but MPE turned out to have too much knowledge of
>what the supported disc models look like to make it practical. Bummer.
>
>Since I met my first HP 3000 in 1980 (40 years ago this month), people would
>talk about what was probably the most rare and exotic HP software subsystem
>ever produced, APL\3000. APL on the 3000 was a project started at HP Labs
>in Palo Alto in the early 1970s. They were likely motivated by the success IBM
>was having with mainframe APL timesharing services. This would be the first
>full APL implementation on a "small" (non-mainframe) computer. It would be the
>first APL with a compiler (and a byte-code virtual machine to execute the
>compiled code), it would include an additional new language APLGOL (APL
>with ALGOL like structured control statements), and it managed to support
>APL workspaces of unlimited size through a clever set of system CPU
>microcode extensions that provided a flat 32-bit addressing capability (on
>a 16-bit machine where every other language was limited to a 64KB data
>segment).
>
>Because APL required these extra special CPU instructions that you got as
>a set of ROM chips when you bought the $15,000 APL\3000, and because
>APL ultimately failed as a product (another story in itself) and thus HP never
>implemented these instructions on their later HP 3000 models, I never saw
>it run on a real HP 3000, but over the years we talked about wouldn't it be
>cool to find a way to get APL running again.
>
>With assistance and moral support from Stan Sieler and Frank McConnell
>and others, I was ultimately able to reverse-engineer the behavior of the
>undocumented ten magic APL CPU instructions needed to get it to run and
>implement them as part of the MPE unimplemented instruction trap and now
>APL\3000 runs again for the first time in ~35 years. Somewhat ironically, this
>implementation method could have been used back in 1980 as I didn't
>actually end up changing the hardware simulation code at all, and it should
>also run (if a bit slowly) on any physical classic architecture 3000.
>
>So that was cool and all, but what is APL without all the weird overstruck
>characters and whatnot? APL\3000 supports the use of plain ASCII terminals
>through blecherous trigraphs like "QD for the APL quad character, but this
>is hardly satisfying. So the quest was on to find a solution. Back
>in 1976 when
>APL\3000 was released, there was a companion HP terminal in the 264x line,
>the HP 2641A APL Display Station, which was basically an HP 2645A with
>special firmware and APL character set ROMs that supported all the APL
>special characters as well as overstrikes (the terminal would take
>X<backspace>Y
>and lookup to see if it had a character to represent Y overstriking X and if
>so it would show that on the display, and if that got transmitted to
>the host it
>would convert it back into the original three character overstriking
>sequence).
>
>I briefly looked into the idea of hacking QCTerm or Putty or something, but
>then I found out from Curious Chris that an HP 2645A emulator already existed
>in the MAME emulator system! Since the '41 is basically just a '45
>with modified
>firmware, and Bitsavers had both the character set ROMs as well as the
>firmware ROMs from a '41, this sounded like it might be easy! There was a snag
>however in that the firmware ROM images that were allegedly from a '41 turned
>out to actually be from an ordinary '45. But we did have the
>character sets and
>one of the ROMs from the second CTL PCA. I put out a call on the Vintage HP
>list to see if anyone might possibly have a lead on an actual HP 2641A, and
>Kyle Owen responded that not only did he have one he could also dump the
>ROMs for us. So a few days and a few hacks to F. Ulivi's MAME hp2645 driver
>later we now have a functioning MAME HP 2641A terminal emulation, so you
>can experience APL\3000 in all its original glory. I bundled up a somewhat
>stripped down MAME along with my turnkey 3000 setup so both emulated HP
>terminals are just a couple clicks away.
>
>So that's how I spent my summer vacation (who am I kidding, it's
>pretty much all
>vacation these days). It has been a lot of fun revisiting all this old
>3000 stuff as
>well as the numerous people I talked to along the way including some of those
>who were around at APL\3000's birth (before my time). It was rather a lot of
>work so I'd like to feel it might be useful to someone in the future
>who is digging
>into this part of history. Because of all the usual reasons, I don't
>plan on hosting
>it permanently until and unless we maybe someday get the licensing worked out
>(the 50th anniversary of the HP 3000 will be in a couple years so maybe people
>will get interested again then) but I will offer it up here to my
>fellow computer
>history nuts if you want to help ensure that it doesn't vanish if I
>get run over by a
>bus or something :)
>
>This is a simulated HP 3000 Series III (circa 1980) running MPE V/R
>(circa 1986)
>with 8MB of memory, all the language subsystems (APL, BASIC, BASICOMP, RPG,
>FORTRAN (66), SPL, PASCAL, COBOL (68), COBOL II (74)), 20 years of users group
>contributed software, many classic historical computer games, etc. Software
>archaeologists can get lost in here for years. Oh, and thanks to Dave
>Elward, the
>HP 2000 Timesharing BASIC contributed library is even included (kinda sorta
>converted to MPE BASIC) for good measure. This is a streamlined
>turnkey edition
>that's ready to run out of the box with no assembly required (all
>batteries are included).
>Currently, I only provide executables for Windows (sorry) but am in
>the process of
>getting the 3000 simulator changes (for large memory support) and the new MAME
>hp2641 driver back upstream. Instructions and further details can be
>found in the
>README.txt hint book for this adventure. 94MB Google Drive link:
>
>https://drive.google.com/file/d/1bmXvHkBLbUeLAid73EJ4H1yQ2uwXQuRu
>
>Gavin
>
>P.S. I'm giving a talk on the history of APL\3000 and its resurrection
>to the ACM APLBUG
>group in a couple weeks. If anyone is interested I can provide more
>details when I have
>them.
There is a 1000uf 10v cap on the main logic board just above the Bt display controller.
It is leaking... a lot. (4/4 samples so far)
Go replace it, flush the area and scrub the with 99.9% IPA.
> From: Liam Proven
> for my continuing education: what's a "Mini-Unix binary"?
Two possible meanings; a system image for a Mini-Unix system (buildable under
V6 with the standard V6 tool-chain of C-compiler/assembler/linker), and user
command binaries (buildable with the C-compiler/assembler, but needing a
special Mini-Unix linker - written in C, and compilable/runnable under V6).
I've done both in my recent Mini-Unix work.
(For those are are not familiar with Mini-Unix and LSX, they are both V6 Unix
variants lobotomized to run on PDP-11's without memory management: -11/05's,
etc. I'm currently working on getting Mini-Unix to run on an -11/03; not a
major change, but not a model supported 'out of the box'. LSX is more heavily
cut down, so it will run on even smaller systems - I seem to recollect 20KB
or so - but that's not that useful nowadays, with semi-conductor memory being
fairly common.)
Noel
A few days ago, it was published on BLOC at CACM that a lost user manual
for the Z4 and notes on flutter calculations was found in the ETH Z?rich
archives. See:
https://cacm.acm.org/blogs/blog-cacm/247521-discovery-user-manual-of-the-ol…
Zuse Z4, a relay computer of 1945,? however, due to lack of
documentation, its functionality was largely unknown. Now a manual for
the machine has appeared at ETH Zurich, that was buried in the archives.
And this in the digital age ...
Thomas
> From: Liam Proven
> Would the x86-32 "reimplementation" of v6 UNIX be able to mount and/or
> read-write such filesystems?
No, it looks like it uses a different fie-system layout.
Besides; there's not much point: the big adantage of using V6 is that one can
use the V6 tool-chain to prepare Mini-Unix binaries; XV6 wouldn't allow
that. If all one wants to do is get files in or out, there's already a program
(compilable with gcc, that uses Standard I/O) to read files out of a V6
filesystem. If there was any good need, it could be extended to write
(although that would be non-trivial).
Noel
I'm in the middle of working out the pinout for the power supply connector
on the MDP-1000. I'm aided somewhat by a set of test points on the
backplane, unfortunately the "+" and "-" symbols (in the solder mask labels
next to the test points) are nearly indiscernible, so I'm trying to verify
that I'm not mixing up + and - 15V.
On the core memory boards are eight Motorola SC5330 IC's (datecodes from
early 1969), which have pins connected to both the + and - 15V lines -- if
I can find a datasheet I could pretty easily confirm which is which.
Trouble is I can't find anything on this chip. I've scanned through the
databooks on Bitsavers, no luck. Anyone have any ideas?
Here's a picture in case that helps at all:
https://1drv.ms/u/s!Aqb36sqnCIfMpIVXm5draSrWHGMzJg
- Josh
> From: Warner Losh
> If we can't use MINIUNIX to rebuild MINIUNIX kernel, should we try to
> bodge together rebuilding via apout?
Good basic idea (using a different system to build on), but there's a
better/easier approach (in the same basic vein): bring up V6, and mount the RK
pack with Mini-Unix on it (it's a V6 file system, so is mountable); V6 is rock
solid running under simulators.
The V6 tools can I'm pretty sure be used directly to build new Mini-Unix
kernels; user program can I think use the V6 C compiler, but I'm pretty sure
not the standard V6 linker (the Mini-Unix linker loads tham at the
non-standard address used by Mini-Unix).
Noel
Question for the group: I have a document set here from DEC that is the
"XT Hardware Handbook". It's basically the entire pre-release
documentation set for the "XT-100" terminal/computer which became the
Professional 325/350.
Is there a copy of this on the internet, and what are the thoughts on
scanning this? Is there already a better copy of this information out
there, this seems to cover the whole internal bus, how the cards work,
and so forth...
Chris
At 01:51 PM 9/30/2020, Noel Chiappa wrote:
>I guess all this PDP-11 hardware detail isn't really on-topic for this list; I
>should move it to Classic Computers, or something.
I've got Riordan's udis[01..10].DSK disk images that I presume
are similar to http://www.bitsavers.org/bits/Terak/mini-unix/
IMD images.
Which filesystem would I find in these images, and which tool
can burst the image into its files?
- John
Hi all --
This is a long shot, but I was curious if anyone might have information on
the Motorola MDP-1000 minicomputer. I picked one up recently and I'm
working on restoring it. Of particular interest is the power supply, which
is external to the processor and which I am missing. I think I have the
voltages worked out (+/-5V and +/-15V), but there are a number of other
signals on the power supply connector that I'm unsure of at the moment.
I've put a few pictures up here:
https://1drv.ms/u/s!Aqb36sqnCIfMpIVYmzKjFnsT3nHh8w?e=b2iqqv
I'll note that this isn't technically an MDP-1000 -- it's labeled as an
MDP-6650 on the rear. I suspect that this is a ruggedized version of the
1000 intended for harsher environments. The front panel of mine appears to
be identical to the drawings of the MDP-1000 in the manuals I have.
It also came with a binder of documentation (but alas no schematics) that
I'll be scanning soon and getting off to Al. It's an odd little system --
5 12-bit registers, a 12-bit ALU, and a 12-bit Instruction Register, but
the memory is 8 bits wide. Instructions are packed into two bytes
normally, but there's a special 64-byte region of memory that can be used
to store "shared bytes," which allow encoding certain instructions into a
single byte, taking the other byte from the shared region. I've never seen
anything quite like this. I wonder why they didn't just use 12-bit wide
memory...
Also the process for using the front panel to examine and deposit memory is
insane. Here's the instructions for reading a memory location; it's 10
steps. Depositing is 17.
https://1drv.ms/u/s!Aqb36sqnCIfMpIVWThgwlxgCMQo59A
If anyone has anything on this, let me know. Not expecting much, but it's
worth a shot.
- Josh
I have a vintage computer sitting in the LA USPS since 9/17, with no
further updates. I have read in the local papers there that the entire
post office has ground to a halt. What's going on there? I have never
heard of anything like this. I assume my package will survive but think of
the zoo there if they've been stacking packages for TWO WEEKS. I'd
strongly suggest not attempting to ship anything out of LA for the time
being. WOW.
I know people complain about the post office, I am not complaining, just
stating the facts. Normally the USPS is reliable. They must really have
overall problems in southern CA due to the fire and related management
issues.
BIll
Sorry I accidentally deleted this message from Dag Spicer, so here it is
for cctalk. Reply to him or the list, not me!
Lawrence
-------- Forwarded Message --------
Subject: Digitizing video frame for printing
Date: Mon, 28 Sep 2020 06:00:21 +0000
From: Dag Spicer via cctech <cctech at classiccmp.org>
Reply-To: Dag Spicer <dspicer at computerhistory.org>, General Discussion:
On-Topic Posts <cctech at classiccmp.org>
To: cctalk at classiccmp.org <cctalk at classiccmp.org>
Hi there,
Trying to help a former operator of a digital portrait scanning booth
?back in the day?? He writes:
++++
IN 1976, I worked at "get your portrait by computer" store.
The heart of the system was a 16 bit, Data General, Nova II computer.
A black and white, analog, standard definition CCTV camera was tethered
to a "digitizer" box that was connected to the computer.
The photographer hit the ?Capture? button on the "Digitizer" box to
instantaneously freeze the image and "digitize" it.
The image was then sent to a Centronics, 102AL, 7 pin, dot matrix
printer to print. A perceived grey scale of 26 shades was created by
numbers and letters.
What I am trying to find out is what the "Digitizer" box was and how it
worked. Ram? Tape loop? I DO know that it said 'Digital Image Systems'
on the outside but have not been able to learn more.
++++
Can anyone help with more information about DIS or generically about
these systems? They were popular in shopping malls for a few years in
the mid-70s?
Thanks for any tips!
Dag
??
Dag Spicer
Senior Curator
Computer History Museum
1401 N. Shoreline Blvd.
Mountain View, CA 94043
dspicer at computerhistory.org<mailto:dspicer at computerhistory.org>
I have two poorly aligned 5.25" floppy drives. They read/write disks
formatted by themselves but are marginal on disks formatted by other
drives. Rather than using a crude "good enough" alignment I would like to
do this properly. Is there still a supplier for 5.25" analog alignment
floppy disks?
Thanks
Tom Hunter
All ?
I?ve done a quite a bit of work with my Seattle Gazelle, and I just did some work on 86DOS.SYS (not released in source form, as far as I know) and its comparison to PC DOS 1.0 (at the code level, a very high correlation as you can imagine). Partially related to that is a program called ?20HAL? which was a code uploader Microsoft used in the late stages to get code from Microsoft in Bellevue to IBM in Boca Raton, FL. I did a little write-up on it here (http://www.classiccmp.org/cini/hal.htm)
There are some holes in the analysis ? I think it?s pretty close, though -- but I?d really like to get some more details on it. Unfortunately, it?s 40-year-old code at this point, and how many people remember how they used a file transfer utility that long ago?
Anyway, enjoy the read. If anyone sees any corrections that need to be made, let me know. Thanks!
Rich
--
Rich Cini
http://www.classiccmp.org/cinihttp://www.classiccmp.org/altair32
Hi,
still working on backing up the Tektronix 440x disks. My current problem
is that the ACB4000 SCSI-to-MFM adapter doesn?t support SCSI parity.
I finally managed to find a PCI SCSI controller (Adaptec 2940) and a
Pentium 4 PC with PCI slots and installed OpenBSD 6.7. I disabled parity
checking in the Adaptec BIOS config and it detects a disk at ID 0 with
no name. So far, so good.
However, OpenBSD always seems to enable SCSI parity and complains about
disk parity errors. I tried to disable all lines in the aic7xxx and
ahc_pci driver source files that seem to enable parity, but nothing
seems to make a difference. The drive/ACB4000 is not detected by
OpenBSD, I get a "device not configured" error when accessing the disk
device files (/dev/sdxc and /dev/rsdxc).
Do you know if is there another OS which would make it easier to change
crucial SCSI parameters in the driver (config) or maybe a specialized
tool that could help me to image the disk?
-- Michael
Hi all,
Since I don't have a machine with qbus and I need to backup some vms and
ultrix tk50 tapes, I purchased a tk50z-ga from ebay.
Upon power up, the red led flashing rapidly(which means drive fault) then
goes to solid red.
I've never used TK50 drives in the past so if you have any hint how to
troubleshoot this it would be appreciated. Or should I start looking for a
replacement?
Regards,
Plamen
On 09/24/20 18:00, cctech-request at classiccmp.org wrote:
> Disabling SCSI parity checking to dump disk on ACB4000
> MFM-SCSI adapter?
I have a sun 3 system with acb4000 and suspect the protocol
was not fully sorted in that time frame. They can be fussy
about what they will talk to, ime.
Would lend a hand if you are in the uk, but otherwise, if
you have an early Sparc system, I would try that, as it
would probably still support the older controllers.
Sparcstation 1 or 2 + Sunos probably has the required
entries in the format utility, format.dat file.
An early pci or isa Adaptec card might be worth trying
as well, under Suse 11.4 or similar, as that has a good
disk utility...
Chris
I've seen plenty of complaints (here and elsewhere) about TK50
cartridges being very difficult to read these days.
I'm trying to read TK85-K (DLT III) cartridges and I'm experiencing
problems. I've had tapes ripped (although I've found that data
elsewhere). So now I'm being particularly careful. If the drive asks for
a cleaning tape, I run through a cleaning cycle until it is happy and
then I try to load the tape again. However, by the time I've mounted the
tape, the drive "Cleaning Required" light is on again. This happens
repeatedly, I run a cleaning pass or two and then I get a green light. I
might even get as far as loading the tape without and issue, but by the
time the tape is mounted, the "Cleaning Required" light is on.
So is this likely to be sticky shed? Is the DLT III formulation known to
have the same issues? Does baking help? (Not that I'm set up to do that,
but I'm in no rush ...)
I suppose that it is possible that my cleaning tape is worn out and now
past its sell by date. Has anyone cleaned a TZ87 or TZ88 head
successfully? It doesn't seem to be terribly accessible, and I'm not
sure what I can dismantle without wrecking the alignment.
Anyone got any useful suggestions?
Antonio
--
Antonio Carlini
antonio at acarlini.com
Something in another recent thread about LISP machines got me wondering:
how many early graphical systems are well emulated (or emulated at all)? I
know that there are more or less functional emulations of Alto, Star, and
Lisa out there, but what about the various LISP machines or the early
workstations (Sun 68K, Apollo, etc) Also, assuming that there are emulators
for some of these systems out there, has any software to run on them and
been archived?
Mike
I am trying to figure out if it is possible to repair a Osborne 1 keyboard.
The keyboard is made by "Oak Switch Systems" and the type is FTM or "Full
Travel Membrane".
The problem I am seeing is that 3 keys ("h", "j" and "y") are permanently
pressed.
I did some experiments with the "h" key.
I measured about 20 ohm across the matrix pins for the "h" key.
I pulled off the "h" key keycap and the white plastic plunger with the both
large and small spring - no change in resistance.
I cleaned the now exposed membrane using Isopropyl alcohol - no change in
resistance.
I applied moderate heat using an electric hair dryer to both sides of the
area around the "h" key - no change in resistance.
I then used a lab power supply set to current limit hoping to zap whatever
is causing the partial short (20 ohm). I slowly increased the voltage and
current limit in short bursts until I hit 100 mA before I gave up the
experiment not wanting to destroy the two flex PCBs feeding into the
membrane. They did get warm but not hot.
I have run out of ideas of what else to try. I still measure 20 ohm across
the two keyboard matrix pins associated with the "h" key.
Has anyone got experience repairing or restoring this type of membrane
keyboard mechanism used in the Osborne 1 and probably in other keyboards
too?
Here are some good and detailed photos of keyboard mechanism:
https://www.flickr.com/photos/123564336 at N03/sets/72157644113347562/
Thanks
Tom Hunter
> From: Lars Brinkhoff
> it was AI rather than MC. As I'm sure you know, AI had the Rubin 10-11
> interface
Really? (I expect you're correct, mind.) I just remember one day MC wasn't
running as normal, and I was told it was because CHEOPS was in some
tournament, and MC had been taken offline so that it could focus on the game.
So I assumed CHEOPS was connected to MC (and had indeed wondered why/how, when
I wrote that message, with the Rubin interface being on AI).
> communicating over Chaosnet. At least, that's how I interpret the code
> in MacHack.
Again, probably right. It was pretty early, but I guess the CHAOSNET was
already running then. My guess is that AI didn't do much but act as a
communication node between CHEOPS and MC, for that.
> There is some debate over whether the CONS had a display of its own, and
> if so whether it could draw to a bitmap. Do you remember?
Not explicily, but I would tend to guess 'no'; I would tend to guess that they
were still in the mindset where it was a specialized co-processor, like
CHEOPS. I certainly don't recall a 'CONS display' in the room where the first
CADR display was; but that doesn't mean much. (Actually, I'm not positive
there was a CADR display in there the night I recall Moon trying to get it
running; for sure a Knight TV console, and he may have been using it to run
something on it to poke at the CADR.)
> they have a hard time pinpointing a birthdate for the CADR. Do you have
> a recollection when, even what year, the first boot attempt was?
Sorry, no; it only stuck in my memory because I was later taken at having
beeen there for the early CADR work; I think that night I only barely knew
what a CADR was. (I was kind of amused that Moon's audience that night was
someone from LCS... :-) I mean, it was pretty early, but I have no idea of
even what year it was.
Noel
I?m looking for a piece of software called Omni-Ware for VMS or UNIX , by a Nashua company called Logicraft.
I?ve just received the pieces to build a Logicraft PC (286 motherboard with custom BIOS and a special network card that emulates the keyboard, mouse, CGA video card and hard disk). I also received the documentation for the VAX/VMS version of the software, but I?m now looking for the accompanying software for VMS or UNIX. The idea is to install this software on a workstation, and connect it to the Omni-Ware PC. The PC then boots off a disk image stored on the workstation, with input and output in an X-Windows window. Logicraft apparently supplied disk images with DOS, Xenix, OS/2 or MS Windows installed.
I?m really hoping someone has a copy of this software still lying around somewhere.
Cheers,
Camiel
> From: Lars Brinkhoff
> There are emulators for the CADR Lisp machine ... There's no emulators
> for the CONS, but I claim it would be interesting to attempt one.
I'm not sure CONS ever ran as a stand-alone system; I suspect (but don't
recall for sure; RG, TK or Moon or someone could confirm one way or the
other) that it ran as a loosely-coupled co-processor to MC, the way the Chess
Machine did.
The CONS and the Chess Machine were both in the same room; 906-907 or
so:
https://gunkies.org/wiki/File:9th_floor_techsquare.png
When the first CADR was built, its console was in the room next door (in the
higher-numbered room direction); I remember watching over Moon's shouulder
the night they first tried to boot it.
Noel
I managed to take some pictures of our Tektronix Smalltalk machines today:
https://multicores.org/pictures/Tektronix_440x/
Both 4404s are identical, including the firmware versions in the EPROMs.
The 4406 is a bit harder to disassemble, this will take some more time.
All of the photos inside this directory are released into the public domain
(and I should get a tripod and better lighting...).
Trying to get our ancient EPROM programmer to work now...
-- Michael
Is there anyone on-list with experience setting-up a Searchlight (or similar) BBS? I have mine up and running with multiple dial-up nodes (for a hopeful future VCF demonstration) but I?m having problems with setting up the file areas properly. If someone could drop me a note off-list, I?d appreciate it. Thanks!
Rich
http://www.classiccmp.org/cini
Long Island S100 User?s Group
Get Outlook<https://aka.ms/qtex0l> for iOS
I re mn ember? GEm5 as a guide ran under dos .? .
Ed#
On Friday, September 18, 2020 Paul Koning via cctalk <paulkoning at comcast.net; cctalk at classiccmp.org> wrote:
> On Sep 17, 2020, at 10:18 PM, Michael Kerpan via cctalk <cctalk at classiccmp.org> wrote:
>
> Something in another recent thread about LISP machines got me wondering:
> how many early graphical systems are well emulated (or emulated at all)? I
> know that there are more or less functional emulations of Alto, Star, and
> Lisa out there, but what about the various LISP machines or the early
> workstations (Sun 68K, Apollo, etc) Also, assuming that there are emulators
> for some of these systems out there, has any software to run on them and
> been archived?
>
> Mike
One system that could be considered a GUI, or at least the beginnings of one, is the PLATO system.? Emulations of that are alive and well, in particular the system described at cyber1.org.
??? paul