I'm working with an old data sample (ca. 1979) to a piece of
equipment that I do not have access to. I've identified some bits
and pieces of code and am trying to identify the processor.
Here's what I know. The processor is big-endian and appears to be
byte-addressable. The opcode for CALL appears to be D3 xx xx, where
xxxx is the address of the destination. 2C appears to be load
immediate instruction and is also 3 bytes long.
The code doesn't look tight enough to be a p-code implementation of
any sort.
Does this ring any bells to anyone?
--Chuck
Last weekend I promised to enable rsync access to the archives
(and mirrors) here.
I've set up the following rsync (no password required) archive sets here:
ftp : Public rsync access to ftp://ftp.trailing-edge.com/ area
pdp-10-tape-images : public rsync access to the PDP-10 tape images,
i.e. http://pdp-10.trailing-edge.com/
bitsavers-mirror : public rsync access to my local bitsavers mirror,
i.e. http://bitsavers.trailing-edge.com/
Suggested rsync commands would be, for example:
mkdir ./pdp-10-tape-images
rsync -rlptu -v www.trailing-edge.com::pdp-10-tape-images ./pdp-10-tape-images
mkdir ./ftp.trailing-edge.com
rsync -rlptu -v www.trailing-edge.com::ftp ./ftp.trailing-edge.com
mkdir ./bitsavers-mirror
rsync -rlptu -v www.trailing-edge.com::bitsavers-mirror ./bitsavers-mirror
Realistically the pdp-10-tape-images and ftp sites don't change often,
butm my bitsavers mirror is kept up to date.
I like to think my outgoing bandwidth (20 Mbit) is pretty much infinite,
this looks like a good way to find out :-)
ftp racks up to 3.5 Gbytes. PDP-10 tapes racks up to 2.2 Gbytes. And
bitsavers-mirror racks up to 126 Gbytes.
Tim.
The 8/L, ASR33, DF32 disk emulator project has been sold. Thanks
for all your interest (and offers). Anyone who wants the DF32
emulator schematic and artwork, I can email you a copy. I hope
someone can take my "first draft" and make a useful unit for those
who are interested.
I have a working ADM-3A that I may want to sell also. It has a
homebrewed lower-case 2716 ROM (thanks Steve Loboyko for the font
files). I installed the "optional" parts for current loop on the
main PCB, and used it with the 8/L. The only thing that's missing
is the little aluminum panel covering the dip switches.
Any interest? Same deal as before, please email offers, "sealed
bids".
thanks
Charles
My Altair 680 has achieved the position of primary attention on
my workbench. All of the ICs are socketed. Not having seen
power in over 20 years, I did not trust the power supply as far
as I could throw a bus. I pulled all of the ICs, attached dummy
loads (automobile bulbs) and powered up. Sure enough, there was
AC all over the place (where there should have been DC). I
replaced all of the electrolytic caps and that got rid of the AC
but some of the voltage levels are very wrong, at least as compared
to what is written on the schematics. The worst offender is just
off the "plus" side of the full wave bridge (BR-1). It should be
nine volts but is actually at 11.5. This makes what should be the
main five volt rail a little more than 9 volts... the far side of
VR-1 (a 7805). The wave form coming off the transformer is really
ugly not a smooth sine wave. I hate power supplies. I don't really
understand, looking at the schematics, what this transformer should
be doing. My guess is that it should be making a nice nine volt,
60 cycle AC sine wave with each of the two outputs 90 degrees out
of sync? What could be wrong with a transformer that it would
produce something like:
__
/ \
| \
/ \_
/ \
| /
| /
\_/
bent and very squared off at spots? My scope shows nice clean 120
coming into the transformer. How do I figure out a part number for
a replacement transformer?
Thanks!
Ok, I have this CX-11 which is a half rack full of backplanes & flip-chips
and has also a half sized lights top panel. It's a Unibus controller to talk
to an IBM bus and tag device. There are 2 large 'In' connectors and also 2
'Out' connectors. I do have a manual which describes some generic IBM info,
but I would like to know what kind of device(s) could (if possible) directly
be connected to such a thing?
Thanks,
Ed
--
Dit is een HTML vrije email / This is an HTML free email.
I find myself in need of an oscilloscope to help me fix my PDP11 PSU (I am
being ably assisted by a member of the list, so don't worry). As this is for
occasional use only I can't justify spending a lot of money. From previous
postings on the list I think I need a minimum spec of dual trace and 20MHz
bandwidth.
Does anyone have any recommendations for what to buy? I suspect it would be
better to get a higher quality used one than a cheaper new one. Perhaps
someone in the UK on this list has one they want to sell?
Regards
Rob
The RetroComputing Society of Rhode Island is doing some
housecleaning, as we need to make room for a new machine (a Cray J). I
will probably offer up some goodies here and on Ebay over the next few
weeks. I might even throw some of the Joe Heck stuff in as well.
We have a couple of MDB Qbus chassis - no cards. Pretty basic 3rd
party DEC stuff. These are rack mount, and are roughly equivalent to a
PDP-11/23.
We would like to get anything over shipping for these. Additionally, I
could probably deliver to any of the NY area hamfests, or even at our
open houses in Providence, RI (generally 3rd Saturday of the month).
We will also have a massive triage of u-fixum VT100s soon. Those will
likely be pickup only.
All proceeds over shipping will go to RCS.
--
Will, in 10512
