I am closing my warehouse by the end of this month. My husband's health is
rapidly failing, and I want to spend what time he has left with him, not
with a bunch of old computers and parts!
Please review the pics here:
https://plus.google.com/photos/106111250846948401252/albums?banner=pwa
But know that the Apple room and the Lisa are gone.
Lots of old keyboards, terminals (like the ones on Halt and Catch Fire),
mono monitors new in the box, IBM 5150 and 5160 with kbds and monitors,
tested working, u name it.
Please also see www.elecshopper.com, make offer for anything you want.
Still have 2 gaylords of IBM compat laptops, 8088 thru 80486 and P1, and 1
gaylord of Apple laptops, from the first ones thru abt 1996 or so.
I would rather this stuff go to someone who will cherish it, then go by the
pound to be ground up.
Also more than 100 computer books from Apple and DOS thru Windows XP and
Server 2003.
Cindy Croxton
Electronics Plus
1613 Water Street
Kerrville, TX 78028
830-792-3400 phone
830-792-3404 fax
sales at elecplus.com
AOL IM elcpls
Hello all,
Has anybody been in contact with Todd Fischer of Fischer-Freitas / IMSAI? I had been in contact with him regarding a manual which I paid for, and apparently got lost in shipping, and I finally just ordered another manual in April, but have not heard from him since. I am not getting any response using his t*f at i***i.net address. Is he OK? If so, has anybody been in contact with him since April? If someone is able to contact him, I'd be grateful if you could help facilitate my getting in touch with him. I'd really like to get that manual!
Thanks,
Dave
I spent some time tonight debugging my problematic 11/05. The current
issue is that Exam and Dep do not increment the address when depressed,
and the PC does not increment when executing a series of NOPs.
I started with the 74181 ALU for bits 0:3, checking the inputs, outputs,
and the function control lines during an "Exam" operation. The inputs
are correct but the outputs are always just the contents of A. The
control inputs (mode and function) are all high, meaning that the ALU
operation is set to just pass A through unchanged, which explains the
behavior.
The control inputs to the ALU are generated by two bipolar ROMs, (named
A11A2 and A20A2) on the M7261 board. The addresses and Enable lines
going into the ROMs look to be correct but the data coming out is all
1s, leading to the incorrect ALU control.
I'm unsure whether these might be faulty ROMs or something else
(incidentally, anyone know what kind of ROMs these are so I might hunt
down a datasheet? The markings on the chips are all different and have
lead me nowhere and the engineering drawings just refer to them as
A11A2, etc. in the parts lists).
Additionally, I cannot find a listing of the contents of these anywhere;
the print sets on Bitsavers and elsewhere have listings for most of the
other ROMs but of course not these two (unless they're tucked away
somewhere apart from the schematics where I've somehow missed them...)
Anyone spent any time debugging the microcode logic on one of these?
Any tips?
Thanks,
Josh
Hi,
The recent thread on AB20 reminded me I have a large pile of CDs from the 1990s
that could do with being imaged and uploaded to archive.org.
What's the best free Unix tool[0] for doing this? Sure, I know about dd and
cdparanoia, but those only extract data and CDDA respectively, and I'd prefer
produce an actual image complete with TOC, subchannels, etc. To *use* the data,
I can always transcode from that into something lossier such as FLAC :) but the
reverse transformation is not possible.
Failing that, I can go off and *write* one, but I'd rather not spend the effort
if something suitable already exists and has already been well-tested and
confirmed to not make subtle errors in rips.
(Bonus points for tips on how to do the same with Blu-Ray discs, since I may as
well archive them now rather than leave it until the 2030s.)
[0] I say this otherwise some berk will pipe up with "you can do that with
SuperMegaRipper Pro from Malware Inc. for Windows 9, and it costs just $299
for a 60 day licence". I'd rather toss the discs in the bin.
I'm currently restoring a couple of VT100 terminals. After checking the
power supplies over and replacing the odd capacitor on the output side
I've had both of them running on a dummy load. They seem to work OK but
I've noticed that R27, which is a large 13W power resistor, gets quite
hot after only a few minutes of being powered on. This resistor is part
of a snubber circuit on the primary side of the main transformer. After
about 5 minutes I measure a temperature of around 95C (200F) on both
power supplies.
Another component that appears to have been quite hot over time (burnt
PCB) is R55, but perhaps this is just an underrated part?
Does anyone have a VT100 and can confirm whether this is 'normal' operation?
Many Thanks,
Matt
And furthermore, does anyone have any documentation on it? I'm curious
as to what it looked like inside. The only thing I could find was a
PDF about a very early Ada compiler for it.
--
Thanks,
Kevin
Q: What was VAXELN written in?
A: The software for the target (OS, drivers, tools, etc) was largely written in VAXELN's own
PASCAL-like language, EPASCAL. The intention was that complete VAXELN systems
(including drivers) could be developed with no need for knowledge of VAX assembler.
There was at one time a VAXELN Source Kit available, which had very little assembler in it.
There intentionally wasn't enough in the Source Kit to rebuild a complete VAXELN OS.
In later VAXELNs, other languages besides EPASCAL were added: VAX C, VAX Pascal, VAX
Ada. Maybe FORTRAN. And VAXELN's own debugger was supplemented by a host/target
variant of the standard VAX/VMS debugger.
VAXELN V4.5 or later (mid 1990s?) is a good place to aim for if you want a fully functional
version, rather than a historically interesting version.
Q: What's VAXELN's current status?
A: Retired, since a long time ago. Not ported to Alpha. VAXELN customers were "encouraged"
to move to VxWorks for Alpha, which would have been a major effort. I wasn't aware of anyone
in UK (or Europe) that bothered making the move.
Q: Who owns VAXELN now?
A: Unclear. It became part of DEC's Embedded + Realtime group, which was eventually sold off
(by Compaq) to SMART Modular Technologies and has since had various owners in the world of
high end embedded/RT systems. When I last looked, last year, Emerson Network Power owned
at least E+RT's PICMG hardware, but that again now seems to have moved elsewhere...
It has been claimed in comp.os.vms that VAXELN wasn't included when CPQ sold the E+RT stuff,
which is entirely plausible.
Definitive info welcome.
Q: What documentation is there for VAXELN?
A: The documentation that exists is to DEC's usual standards. Hardcopy and bookreader
versions of most VAXELN docs exist; the bookreader stuff is available online. I am not aware of
PS or PDF versions (there were internal-only PS versions).
There was/is a PC version of Bookreader, for those that don't yet have a VMS system.
The VAXELN Technical Summary is an excellent mini-book, if you happen across one. It'd be
nice if there was a copy online; I'm not aware of one.
The excellent VAX Realtime User's Guide, EK-VAXRT-UG001 (1986!) covers using VAX for
realtime applications on both VMS and VAXELN, in some considerable depth. Also not
immediately locatable online, sadly.
DEC EduServices used to have some nice training materials for VAXELN, going back a very long
time. Unlikely to be online.
There have been occasional VAXELN-related discussions in comp.os,vms, e.g. on 1 March 2007
I replied re VAXELN to a query on "History of VMS and related operating systems", see e.g.
http://unix.derkeiler.com/Newsgroups/comp.os.vms/2007-03/msg00014.html
(Google Groups links are not helpful as they are very likely to rot over time).
hth
john wallace
I have started playing with the rtVAX 1000 I collected last year. It was
running OK when then was a sudden bang and the machine stopped. Not even the
fans will run. There was no smell and no smoke, so I knew immediately that
it can't be the mains filter capacitors, which always fail on these power
supplies.
I have opened it up and cannot see any damage in the PSU, the CPU, the
memory, or any of the other boards. I am sure it must be the power supply,
but I really can't see any damage. The power supply is one of the ASTEC ones
common in the MicroVAX II.
My first step is going to be to test the PSU with a dummy load using light
bulbs (still haven't built a board for a dummy load) and with the fans
connected, but nothing else. Will also check for ripple at the same time.
There are two outputs from the PSU that I don't fully understand, one is P
OK, I am guessing that means *something* is OK, but not sure what, power
perhaps, but what power?. The other is called LTC, I have no idea what that
one means. Can anyone enlighten me?
Any other ideas?
Regards
Rob
This is a followup to my previous email (attached)...
I just finished reading the PDP-5 Users Manual - and discovered the
following statement regarding the "operate instruction" (note: words in
parentheses are mine):
"Any logical combination of bits within this group (Group 1) can be
combined into one microinstruction. For example, it is possible to
assign ones to bite 5,6 and 11; but it is not logical to assign ones to
bits 8 and 9 simultaneously since they specify conflicting operations
(bits 8&9 are rotate right and rotate left). If RAL or RAR is
specified, neither CMA or CML may be specified, and conversely. If RTL
or RTR is specified, neither CMA, CML or IAC may be specified, and
conversely."
So the PDP-5 was even more restrictive with regard to microinstructions
than the PDP-8/S!
Matter of fact, I'm now even more impressed how Saul Dinman was able to
design almost all of the functional capabilities of the PDP-8 into the
PDP-8/S's compact package.
In addition, while the PDP-8/S was only about half the performance of a
PDP-5, the price of the PDP-5 was $27,000 while the price of the PDP-8/S
was about $10,000 (4KW core, including TTY). In that context, it was a
pretty good deal...
Cheers,
Lyle
------------------------------------------------------------------
Date: Wed, 16 Jul 2014 17:31:45 -0700
From: Lyle Bickley <lbickley at bickleywest.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: PDP-8/S Incompatibilities......
I've had my PDP-8/S up and running for some time - but have recently
experienced failures using some PDP-8 software.
My 8/S passes all the DEC diagnostics - and it runs FOCAL-69 and 71
perfectly.
So I decided to track down what was causing some programs to fail - and
I discovered that the problem is PDP-8/S incompatibilities.
PDP-8/S "Reality"
-----------------
The PDP-8/S User Manual lies! It makes the following claim
regarding Group 1 Operate Instructions:
"The only restriction on combining OPR 1 (Group 1) operations
within one instruction, other than logical conflicts, is that
a rotate operation (bits 8, 9 or 10) may not be combined with
the increment AC operation (bit 11) since they are executed
during the same bit times."
I decided to test that claim on my PDP-8/S and got the
following results (via single stepping through the test
program below.)
The "8/S" column is Link AC contents (L AAAA):
*200 Page 1
1 0200 *200
2 /AC 8/S NOTES
3 00200 7200 CLA /0 0 0000
4 00201 7201 CLA IAC /1 0 0001
5 00202 7326 CLA CLL CML RTL /2 0 0002
6 00203 7325 CLA CLL CML IAC RAL /3 1 0003 8/I AND UP
7 00204 7307 CLA CLL IAC RTL /4 1 0001 8/I AND UP
8 00205 7327 CLA CLL CML IAC RTL /6 1 0003 8/I AND UP
9 00206 7215 CLA IAC RAL RAR /10 1 0003 6120
10 00207 7203 CLA IAC BSW /100 1 0001 8/E AND UP
11 00210 7332 CLA CLL CML RTR /2000 0 2000
12 00211 7354 CLA CLL CMA RAR RAL /3776 1 7777 8/I OR 8/L
13 00212 7350 CLA CLL CMA RAR /3777 1 7777
14 00213 7330 CLA CLL CML RAR /4000 0 4000
15 00214 7352 CLA CLL CMA RTR /5777 1 7777
16 00215 7333 CLA CLL CML IAC RTR /6000 1 0003 8/I AND UP
17 00216 7346 CLA CLL CMA RTL /7775 1 7777
18 00217 7344 CLA CLL CMA RAL /7776 1 7777
19 00220 7240 CLA CMA /7777 ? 7777
20 00221 7402 HLT
21 $
No detected errors
No links generated
Note that all of the CMA shift instructions failed - even
though the test (from Programming Languages) thought they
should work in pre-8/I machines.
At first I thought my PDP-8/S was failing - until I found the
following from the PDP-8/S FAQ (What is a PDP-8/S?):
"Compatibility: The core of the PDP-8 instruction set is present,
but there are a sufficient number of incompatibilities that, as
with the PDP-5, many otherwise portable "Family of 8" programs
will not run on the PDP-8/S. Perhaps the worst incompatibility
is that the Group 1 OPR instruction CMA cannot be combined with
any of the rotate instructions; as with the PDP-8, IAC also cannot
be combined with rotate."
I decided to understand WHY this happens - and the answer
is in the PDP-8/S Maintenance Manual and the PDP-8/S
schematics. I've abreviated the sequence of execution
below. (The "Ax" references are bit timimg):
Group 1 Instruction Sequencing
------------------------------
Fetch
-----
A12 Set or Clear Link, Clear AC per instruction
Execute
-------
A00 For right rotation (A00-01), shift AC+L together
once or twice per instruction
A(00-11) IAC: Adds one to AC
CMA: Complements the AC
IAC*CMA: Complement and add one to AC
Left Rotate: AC+L shifted right 11 or 12 times
per instruction
A12 IAC: Complements L on overflow (CMA appears
in gating, but has no effect)
As can be seen, while the system clears the AC and clears
or sets the Link during Fetch - it rotates right BEFORE
complementing the AC! It also attempts to execute a complement
of the AC at the SAME TIME as a left rotate - which simply
does not work!
Finally, just to verify the correctness of the test program,
I single stepped it on my PDP-8/E and got the same results
as the SIMH trace below:
SIMH PDP8 Trace of the above:
-----------------------------
sim> sh cpu history
PC L AC MQ ea IR
00200 1 7777 0000 CLA
00201 1 0000 0000 CLA IAC
00202 1 0001 0000 CLA CLL CML RTL
00203 0 0002 0000 CLA CLL CML IAC RAL
00204 0 0003 0000 CLA CLL IAC RTL
00205 0 0004 0000 CLA CLL CML IAC RTL
00206 0 0006 0000 CLA IAC RAL RAR
00207 0 0001 0000 CLA IAC BSW
00210 0 0100 0000 CLA CLL CML RTR
00211 0 2000 0000 CLA CLL CMA RAL RAR
00212 0 7354 0000 CLA CLL CMA RAR
00213 1 3777 0000 CLA CLL CML RAR
00214 0 4000 0000 CLA CLL CMA RTR
00215 1 5777 0000 CLA CLL CML IAC RTR
00216 0 6000 0000 CLA CLL CMA RTL
00217 1 7775 0000 CLA CLL CMA RAL
00220 1 7776 0000 STA
00221 1 7777 0000 HLT
sim>
Cheers,
Lyle
--
Bickley Consulting West Inc.
http://bickleywest.com
"Black holes are where God is dividing by zero"
--
Bickley Consulting West Inc.
http://bickleywest.com
"Black holes are where God is dividing by zero"
