On 19/09/2004 Sellam Ismail wrote:
>I made an initial phone call to Don's number and got an answering machine
>(presumably Don's voice is still on the OGM). I chose not to leave a
>message. I'll try again later today.
Sellam, I'm shocked by your lack of tact and respect. No matter how
important Don's collection might be in your eyes, you shouldn't lose
sight of the fact that his wife and family have just lost him. They
probably couldn't care less about what happens to his stuff in the
garage at this point.
I've asked my wife for her opinion on this and she said that she
would instantly scrap and toss my stuff if she ever found herself in
a similar situation. I can't blame her.
What do others think of this ?
Greetings, Jos
_________________________________________________________________
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Hi Tony,
>> It looks like the on-board CPU is not running at all.
>
>I would guess that's likely to be the case (although I've never worked on
>this unit).
>
>In which case I'd start by checking the +5V power rail, then check the
>CPU clock and reset pins (make sure the thing isn't held in the reset
>state), then see what the aaddres and data lines are doing.
All good advise - assuming that it's running (clocked), and the address/data
bus looks ok (being driven, no signs of contention etc.), data being fetched
>from the ROMs, I would probably next check the ROM content against the image
on funet (I've seen a number of these ROMs go bad).
Opened it up this morning - unfortunately, it is very badly corroded inside,
and the drive unit itself shows a LOT of rust.
Some of this equipment originally was rescued from a shed which we were told
flooded with water every year - one casualty was a 2040 disk unit which has
**VERY** badly corroded drives and plenty of rust all around the lower section
of the case - we also have a B128 in which the edge connectors and any exposed
sections of copper have gone green and fuzzy - not to mention all lables/stickers
etc. have disintegrated - amazingly, after an initial cleaning of the worst of
it, the machine still works! - one of my upcoming tasks will be to completely
clean it up and restore it.
I'm guessing this drive must have also been near the bottom of the pile.
Board looks not too bad - power supplies check out, after cleaning and reseating
all of the socketed chips and connections it still appears completely dead, so
now its on to more serious debugging...
Replaced ANOTHER 4116 DRAM in a CBM 2001-N last night - this makes 7 or 8 I've
changed so far - symptoms are always the same - amount of memory "found" by BASIC
differs, usually higher when the machine is cold, and lower if the machine is
reset after it warms up (meaning the RAM gets worse after it has been on a while).
Fortunately most of them have been able to run BASIC or at least the diagnostic
monitor, and a little pokeing and peeking identifies the bit which is affected,
allowing me to locate the exact chip without to much trouble.
Have also replaced 4-5 2114s - I'm amazed that so many RAMs have gone bad in the
Commodore equipment...
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Vintage computing equipment collector.
http://www.parse.com/~ddunfield/museum/index.html
I just received this manual:
Science Fair
SF-5000
ELECTRONIC COMPUTER
by Rolf Lohberg
PROGRAMMING MANUAL
and Assembly Instructions
Engineered For
Science Fair Electronics - A Tandy Corporation Company
Copyright 1971
by FRANCKH'SCHE VERLAGSHANDLUNG. KOSMOS
Stuttgart, West Germany
I had all but forgotten these things - in fact when they guy who
gave it to me described it over the phone, I could not place it - but
when I saw the picture on the cover I recognized it.
This is the Radio Shack version of the Kosmos "Logikus". It is a
small flat device with ten multi-position slider switches which move
in and out of the front. At the back is a raised panel with ten lights
which can illuminate various cards that you slide into the front of
the panel.
Along the top (in front of the panel) are many holes in which you insert
wires to "program" the device. My making connections between the various
switch elements and the lights, you can demonstrate fundamental logic
concepts such as AND and OR.
The manual includes a number of simple games and some basic mathmatical
functions - it consists of 112 pages + covers.
Aa timer permits, I will scan it an post it to my site.
Regards,
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Vintage computing equipment collector.
http://www.parse.com/~ddunfield/museum/index.html
Anybody know what this is for? Roughly 6 x 8"square with LEDs for D0
through D7 and A0 through A5. Also LEDs for -15VDC, +15VDC and +5VDC. Six
position DIP switch for setting the board address. Only connector is a 50
pin ribbon cable header. Keithly sells Metrabyte but neither Kiethly or
Metrabyte will give you any information. Good companies NOT to do business
with IMO.
Joe
Hi, I've just been given a compaq slt/286, knowing nothing about them,
I seached the net for info and found yourself, do you still have guide and manual?
If so it'd be a great help, (nice to put the two things back together as mine is in original carry case)
If you've still got it, or can even give me any info/advice about it, email me at monikadonald(a)v21.me.uk
yours hopefully,
Donald Jarvie.
Best rule for SIMH or E11 purposes is
NOT to mix "RM" and "RP" drives on a single RH11/RH70.
--
There was some discussion/questions from Bob Supnik about this
on the simh developers list this week if mixed drives were or
were not supported on the PDP11 operating systems. It sounded
like they were not, so I'm surprised that they may have been
on V9 and earlier.
The problem comes about because the RM and RP massbus controllers
have slightly different register sets.
The complete thing is scanned and indexed (minimally) at
wps.com/projects/LGP-21/Documentation/LGP-21-Maintenance-Training-Manual/
I'm not completely happy with the index, but URLs etc won't change when
I fix it. It's not entirely obvious that to see page 6-36, not in the
index, for instance, that you can get there by clicking NEXT PAGE on
page 6-35. No matter, the scanning is done other than to fix a few
crooked pages.
If anyone wants a copy send me SASE that'll hold a CD-R and I'll save
you the trouble of downloading.
Could someone please take a closeup photo of the DEC/PDP logo on their
11/03 or 11/23 and send it to me? Or point me to a site which have it? I
need to match the paint for the logo restoration.
--
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=1247&item=5124508154
the logo is a sticker on the 11/23's
Cleaning in the basement I came across a card
with the following text
ampex
write amplifier
test card 61145-03
d9756-461
the pins there are 10 leads a gap then 4 more
3.25" x 7.75"
Any idea what system this goes with?
--
Collector of vintage computers http://www.ncf.ca/~ba600
Looking for: PICMG backplane
Open Source Weekend http://www.osw.ca
Something else that I found this morning. A circuit board about 3 x 5"
square with four toggle switches and a push button switch. The toggle
switches are labeled Freq (0,1), WREN (off,on), Hold (off,on) and DRCT
(out,in). The pushbutton is labeled Step and next to it is a LED labeled
TRK 00. On the other end of the board is long wire with a E-Z hook on the
end of it. Next to where the wire is connected it says Connect to A5 TP9.
The part number on the board is 98015-66501. On the back of the board is
DE-37F connector. There are no other connectors or power jacks so
apparently it gets it's power from the DUT. I'm guessing that it's used
for testing some kind of HP disk drive. I think the HP 9885 disk drive uses
the DD-37 connectors so I think it might be for that. Anyone know any more
about it?
Joe
