Hi all -
Anyone have any technical information (manuals, schematics, etc.) for
the DEC DW11 UNIBUS->QBus interface? I'm curious to know what it's
capable of and what the requirements are, especially on the QBus side of
things. What kind of backplane is required? I assume it doesn't
support 22-bit QBus devices given the age of the interface (and the
complexity required to do so), but does it handle 18-bit devices, or
I haven't found much technical information on it at all. Anyone have
any details to share?
I'm wondering where the MIPS I-IV standards that are referenced
everywhere are defined. I was able to actually find what seems to be the
IV standard  but found no such thing for I-III. I didn't even find
any bibliographic references to them. Did they only exist as printed
books and nobody bothered to scan them? Or are they under copyright?
Would be nice to have them accessible somewhere.
It's been about a year since I last asked around, so I figure it's
time for me to put out another call for help.
My AT&T 3B2 emulator sits unfinished due to lack of internals
documentation. If you or anyone you know might have access to
internals documents -- schematics, timing diagrams, etc. -- please let
These docs are very hard to find, and may never have been released by
AT&T. Maybe you know a former AT&T engineer who managed to squirrel
I have many resources already, so I'm NOT looking for user manuals,
SVR3 source code, or the IO Bus specification. These are pretty
easily available online, and they've given me their all.
Many thanks in advance,
web at loomcom.com
Does anyone have (a scan of) a manual that covers programming the MV-era
MTB tape controller?
I have a 1980 "Peripherals" manual (014-000632-01) from the
"Programmer's Reference Series" which covers the MTA type, but it seems
that the MTB behaves a bit differently and I am missing some information
for my current project.
Email: steve at stephenmerrony.co.uk
I have been given an H960 rack :-). I intend to use it for my PDP8/e system
(currently piled up, not connected), which consists of the :
PDP8/e processor, Full of cards, memory extension, EAE, 32KW core, boot
diode matrix ROM, RK8e, RD8e, RX8e, PC8e, etc.
PC04 paper tape punch/reader (acutally, I converted a PC05, but that doesn't
RK05 (well, there's an RK8e in the backplane and I have a spare RK05 so
I might as well use it)
TU56 (single drive version, ths is not a TU55 as some have suggested!).
Various PSUs and step-down transformer for the TU56 and PC04
I think I have the right slide rails for the first 4 units too...
Anyway, does anyone have experience of rack-mounting a TU56? It clearly
doesn't go on slide rails, it bolts directly to the rack (hinge down the front
panel for access). I have the manuals from Bitsavers, they imply there is some
kind of spacer block that goes under the TU56. Does anyone know what that
is exactly so I can attempt to make one if it is needed.
A selection of some of my more unusual computer-related stuff:
- A Tektronix 4132 Unix workstation using a National 32016 CPU and a 4.2bsd port called UTek
- A Digital Equipment PDP 8/e system with 2 RK05 drives, high speed paper tape reader/punch, RX01 Dual 8" floppy drives, 16K of DEC core memory(commonly runs with a 32K NVRAM board), 2 serial ports, EAE, RTC, Memory Extension/Timeshare board, Diode boot board (RK05 boot)
- Wang 300-series calculator field service parts kit (two wooden briefcases)
- Friden 6010 Computyper Diagnostic Console
- Friden Electronics Training Course manuals (1960s)
- Wyle Laboratories WS-02 punched card programmable electronic calculator (1964)
- Busicom 207 punched card programmable electronic calculator
- Altair 8800 with Altair dual 8" disk drives
- IMSAI 8080 kit built in high school as a school project in 1976/1977
- Televideo Personal Terminal
- GE transistorised current loop acoustic coupler modem (110 baud)
- Hewlett Packard 9100A and 9100B programmable electronic calculators
- Tektronix mini-Board Bucket computer and many boards for it (EPROM Blaster, TI TMS9918-Based Video Board w/RTC, SASI Interface, 6809 CPU, 6809 ICE CPU. 32K Static and 64K Dynamic RAM Boards, 300-Baud Modem Board, 5 1/4" Floppy Controller
- SWTPC TV Typewriter
- A large format (4'x5') Summagraphics digitizing tablet with GPIB interface
- A Tektronix 4052 desktop computer (bit-slice implementation of Motorola 6800 CPU) with very rare RAM Disk module installed under keyboard
- Wang Laboratories dual-cassette drive for 700 series calculator
- An old fluorescent-lighted, two sided sign advertising Denon electronic calculators
- Some original Digital Equipment System Modules (Used by DEC for making some of their early computers)
The Old Calculator Museum
Via Mike Ross, but contact Greg with any questions!
---------- Forwarded message ----------
From: "Greg Bebermeyer" <bebergee at gmail.com>
Date: Feb 27, 2017 4:44 AM
Subject: IBM System/32 - web response
To: <mike at corestore.org>
Maybe this is no longer relevant since I can't tell from the web page
how recent the post is... I am selling my house and in the back of the
garage is a complete System/32 that was working when I stuck it there
and covered it. Much other stuff is in front of it so I haven't seen it
in a while. It's free for the taking to anyone willing to come to East
Lansing, Michigan and pick it up. If you aren't interested then it'll
just go to the scrappers because I need to get the place ready for
inspection. The junk haulers should uncover it in a day or two at which
point I could take pictures.
I also have a PDP-11/60, if you know of anyone interested. Same deal -
free, come pick it up. The 11/60 main box has been stored in a dry
basement along with two RL01 disk drives (in free standing cabinets, not
rack mounted) along with a box of flat interconnect cables. It was used
in a cardiac unit to run heart monitors and has an extra card cage full
of interface cards. Also there's 3 PDP-11/34s in a rack in the garage as
well. All this stuff has to go in about a week to 10 days, unless
arrangements/promises are made and kept.
If you're interested in any of this stuff, or could refer me to someone
who might be, I would love for this stuff to go to a good home. Yup, I
started with FORTRAN and 80-column punch cards. Thanks.
bebergee at gmail.com
greg.bebermeyer at gmail.com
Lawrence Wilkinson lawrence at ljw.me.uk
The IBM 360/30 page http://www.ljw.me.uk/ibm360
Analog, which is my nemesis, curses me again.
I have a cute idea for a cassette port project for the Tandy line of
computers (the ones with the cassette port). I have a Coco 3 on the
bench, so I scoped the output line while doing 'csave "jim"'. The
signal looks to be just under 1V PtP (0-1V on the scope), and rests at
about .3V when not sending data.
I have tried 6 different ways to boost the signal to 5V digital, to no
avail, and so I ask humbly if someone with analog knowledge might be
able to assist.
I first tried to boost the signal with a transistor (with variations
using a N channel FET as well). Arguably, that was foolhardy, and it did
My second attempt was based on this link that was shared with me:
The output from the Coco3 does not appear to be "loud" enough to work
with this circuit.
So, I finally decided a comparator solution would be required.
First, I tried a design using a 741 op-amp, which failed miserably, but
probably would have worked, but I tried to merge the design from the
Coco1, and replace the LM339 in the Coco 1 design with the 741, and I
feel I did not merge the designs well :-)
I then tried using the comparator in an Atmel AVR, and had minimal
success. By biasing one input via a variable resistor to around .8V, I
was able to get a digital stream, but it did not look like the data
stream of the cassette format.
I then pried an LM339 out of my Coco1 and replicated the circuit int the
Coco 1, as noted in the tech manual:
Color Computer Technical Reference Manual (Tandy).pdf
I was shocked that I had no success with that design at all. I assumed
(wrongly, it appears) that the Coco cassette input circuit would read
the output of it's output circuit. Beyond the possibility that my
components are defective or I wired it up wrongly, I can only theorize
that Tandy assumed that all tape recorders would AGC the output and then
feed a 2V PtP signal back to the Coco (the Coco 1 circuit looks to bias
the comparator at 1.05V (not sure about the feedback resistor's impact))
I can fiddle around with the AVR solution, which might work if I can
smooth out the spikes and bias the comparator right, but it just bothers
me that the Coco 1 circuit does not work, as I assumed I would at least
have success by copying a working design.
brain at jbrain.comwww.jbrain.com
I don't know if anyone here has the interest or capability to do it, but
creating a replica of the blue tape trays with the clear overlay that
one could sell for a few bucks with some random fanfold copies of DEC or
other diagnostics would be nice.
Perhaps if there were a ready source of replicas with a perpetual
listing or 10 to overwhelm the auctions with 100 and 300 dollar auctions
for the genuine originals the originals would be listed and sold for a
I'm sure there there are things going to people with no idea what they
have which would have been nice to image and save. I would think
someone with vacuum molding and some skill with plastics could do the
trays. not sure about the source of tapes to sell with them, maybe that
does justify some extra expense.
People with working readers and libraries of tapes might like them as well.