Hi all --
Last night I finally got the Imlac working to the point where I can run
programs more advanced than a light chaser, and I'm using my newfound
abilities to take a closer look at the functionality of the system's core
memory. This is a Dataram "DR-101" system (Docs are on Bitsavers now), 8KW
of 16-bit words and when I got the Imlac all the socketed ICs on the
control PCB were extremely corroded. I outright replaced the corroded ICs
(most of them were too far gone to deal with and the rest were marginal)
cleaned the sockets, and at this point it's fairly functional.
I whipped up a simple program to walk through memory and test every
location (by writing / reading back all possible 16-bit values at every
location). The results are mostly positive, aside from a small addressing
issue (the upper two MSBs of the address from the CPU are apparently being
ignored by the memory's addressing logic so I get 2K repeated over and over
again).
What I did find was that most of the memory I'm currently able to test (the
repeated 2K) tests out fine. However, there are a few addresses in the
210-240 address range that either have dead bits or behave sporadically,
and there's a single bit near the top of memory that's stuck off. The
failures are 100% consistent (even the sporadic failures always show up at
the same addresses) and reproduce identically if the system is "cold" or
has had time to warm up for awhile.
I'm not sure whether to suspect calibration/alignment issues here -- I
would expect failures to be more widespread or have repeating patterns of
some sort if the system was out of alignment. I'm tending to think that
the core plane may actually be damaged in places, which would be very
unfortunate. However, I don't have a lot of experience in diagnosing core
memory failures; so far I've been fortunate -- the systems I have that use
core memory have not had issues with the memory.
Anyone with more experience here have any suggestions?
Thanks as always (and yes, I'm still working on the 8/L current loop stuff
I've just been distracted because apparently I have no attention span and
thanks again for all the help there :)),
- Josh
I found homes for some of my TeleVideo systems at VCFMW, but still have a
lot left. In getting the ones I sold ready, I ended up finding quite a
few systems that were not functioning. So, I will be testing every system
this week to find out the ones that have issues, and will know what I have
that works/doesn't work.
If anyone is interested either in working systems, or possibly systems with
issues, let me know. Some of you have expressed interest already, but
please feel free to let me know again if you are interested.
I'd love to find buyers locally on CCTALK, but need to get these out of the
garage, so Craigslist, and then eBay, are my next steps.
Here is a list of what I have currently:
https://docs.google.com/spreadsheet/pub?key=0Ahk4_RQTUNcYdFpTOFQ3RFdMQ0FocE…
Thanks,
Garrett Meiers
www.linkedin.com/in/theunixguy
Sorry to keep pestering the list. I have an idea...
Is there any really old original SGI hardware out there? I'm talking
the pre-MIPS stuff, that was used as a graphical front-end to VAXen
and other items (IRIS 1000) or even IRIS 2000 equipment.
--
-Jon
Jonathan Katz, Indianapolis, IN.
Hello
In the mid 80ies i was at school in Sk?vde Sweden.
At that time that school had a PRIME 9955 system together with the
normal serial terminals and also a fair number of specialist CAD
workstations.
The CAD stations was used for MEDUSA and another Electronic CAD package
(we did PCB designs in that system.)
I have two questions (because of a foggy memory):
what was the maker of the work stations (or who could they be) ?
and
could someone name a number of pcb design programs for PrimOS ?
2 Complete 128 Machines
with 1902 Monitors
Each with a 1571 that needs work
One has a Ketec Command Center
And Mice with each
$200 for the lot. Would prefer Local Pickup since these are a pain to ship
Steve
So I have recently been given half a dozen Acorns - one Model A, 4
Model B+ with 64K and one 128K B+.
I'm going to donate the Model A, at least, to TNMOC at Bletchley, but
I'd like to keep at least one for myself.
The thing is, whereas I wouldn't just turn on a 1980s business
computer with multiple moving parts, the donations chap at TNMOC has
put The Fear into me by sternly warning me Not To Turn Any Of Them On,
because They Will Blow Up.
So, how does one go about testing a mucky old Beeb that's not been on
in 25y or something & has been stored in a dusty attic?
Give it a good clean, I guess, but can one hook one to a PC PSU and
test its internal PSU in isolation?
--
Liam Proven ? Profile: http://lproven.livejournal.com/profile
Email: lproven at cix.co.uk ? GMail/G+/Twitter/Flickr/Facebook: lproven
MSN: lproven at hotmail.com ? Skype/AIM/Yahoo/LinkedIn: liamproven
Tel: +44 20-8685-0498 ? Cell: +44 7939-087884
Folks,
Anyone have a manual for one of these? The 512 is online, but I can't
seem to find one for the '1000. Presumably this thing speaks 4010, but
I'd like to know more about all the assorted connectors and such.
Cheers,
De
Hi everyone!
I found that one of the manuals I have is actually single-sided pieces
of paper, which means I can use my cheap sheet-feeder scanner. I
started the manual, and this is what I have.
https://www.dropbox.com/sh/tud9lsq6f9z43bj/Td9vaTGwKz/multimax%10-beginning…
--
-Jon
Jonathan Katz, Indianapolis, IN.
I have a marginally functional KYBE MLC400 tape cleaner that I'm going to be
recycling.? It is almost functional, but one of the cleaning tissue spool motors is
missing and the other three motors appear to be non-functional and requiring
rebuilding.
This thing is big and heavy, at least 70 lbs.? I don't have materials for crating
or boxing it for shipping.
I'm going to be recycling the unit.? But before I do that, I'll make any parts on
the machine available FFS.
If anyone has an MLC400 in need of parts, contact me ASAP.? My next recycling
pick-up is in a week, and I intend to gut it of any useful parts for hobbies so let
me know if you need anything for your unit.
Alternatively, anyone in the Minneapolis area can pick up the entire unit.
-scott
