Hello
I have a couple of VAXstation 3100s - a M38 which boots but has no output
on the console port, and another model which has corrosion on the
motherboard and a PSU which doesn't power up correctly.
The voltage on all of the M38 PSU's pins is OK except for pin 7 (brown)
which is +3.5v to +5.25v DC and is floating at about 0.6v with reference to
ground. I suspect this is why the console port doesn't work (and the LEDs
on the read suggest a RAM problem so I can't tell which chip is faulty), so
I've set about troubleshooting.
Does anyone have any suggestions above and beyond replacing capacitors?
Peter
--
OpenTrainTimes Ltd. registered in?England and Wales, company no.?
09504022.
Registered office: 13a?Davenant Road, Upper Holloway,?London N19
3NW
Until a few minutes ago, my VT240 was operating normally, but now it's
unresponsive (fails during power-on self test).
Normal behavior was: display a checkerboard, then two different
intensity all-white bands growing slowly up from the bottom of the
screen, then a beep and the expected "VT240 Monitor Error 9" (because
I'm using an old B&W composite monitor instead of the DEC VR201 with
special cable). Thereafter, normal operation.
Now, it briefly displays the checkerboard (and all four keyboard lights
turn on, then off); then the Lock and Wait lights come on and nothing
else happens. Blank screen.
Power-OK light on the back is illuminated and 5.19 volts measured on the
board. Haven't checked +12 (or the internally derived keyboard +5) yet.
Another possibly useful observation: I can press the Setup (or any
other) key about four times and hear a keyclick sound each time. But
then it stops playing the click sound if I keep pressing keys. This
suggests that the interrupt on the CPU (a T11) is not being responded to.
The technical manual is very detailed but does not describe the
specifics of the POST, which could be useful in locating the failed
circuit (or firmware).
Can anyone with experience in debugging these terminals lend a hand?
Should I even be looking at the main board, or the keyboard which also
has an 8051 CPU??
thanks.
Hi everyone!
My wife found some interesting VME-looking boards for sale on a surplus
auction website. This is what we scored. Is there any interest for these
here?
1x Main CPU SKP-220-3
4x Sub CPU SKP-221-3 (2 look good, one has a battery that exploded all over
it, one labelled bad CMOS but had a bent pin.)
3x Servo SKP-222-3
1x IO Board SKP-184-2
I have no card cage, no documentation, and no way to test these. Some are
labelled that they tested good in 2008. I'll happily supply pictures for
those interested, but they're essentially 2U VME boards with MC68000 chips
and the main CPU has an MC68HC000 CPU.
They seem to fetch a fair sum on eBay, but just because they're listed at
these prices doesn't mean that they actually sell at that price:
https://www.ebay.co.uk/itm/Seiko-Epson-Accu-Sembler-Robot-Control-Sub-CPU-B…
--
-Jon
+44 7792 149029
I know the response to this might be quite subjective and depends on
your particular interests.
Do BYTE magazines have any collectability (maybe even from a historical
perspective or something else)?
I have to make some decisions about space (the perennial problem for a
collector of course) and I have quite a few of these taking up a few
shelves.
Thank you.
Kevin Parker
You know, reading about this made me dig out the info I had on the Character Oriented Windows ("COW") library. I was reading some of the docs and it occurred to me that it operated much like Windows (probably Windows 1), but what I couldn't find were any "sample" programs or tools to build a program based on the COW library. Does anyone have/know of a sample program that used the library? Was there an SDK for it or was it used only for Microsoft's products?
Just looking for something new/interesting to learn about. Thanks!
Rich
?On 5/22/20, 11:35 AM, "cctalk on behalf of Chuck Guzis via cctalk" <cctalk-bounces at classiccmp.org on behalf of cctalk at classiccmp.org> wrote:
A quick look at the code indicates to me that the Intel translator
CONV86 may well have done the translation in "strict" mode. Of course,
there were other translators, but some of the stuff rings a bell.
For example, the 8080 instruction
INX B
gets translated to
SAHF
INC BX
LAHF
all done because the 8080 16-bit instruction does not affect the zero
and carry flags, but the 8086 instruction INC, does. So there's very
likely a large amount (my experience was at least >30%) of cruft in the
code.
--Chuck
I assume this are not the standard Intel floppy drives????
On Sunday, May 31, 2020 Jan-Benedict Glaw via cctech <jbglaw at lug-owl.de; cctech at classiccmp.org> wrote:
Hi!
I just wanted to drop an email that there's a MDS 80 on eBay:
??? https://www.ebay.de/itm/333612000595
(Please note: The seller, Michael, is a friend of mine, and a former
coworker.)
Thanks,
? Jan-Benedict
--
