I was visiting a data-center-not-to-be-named and talked them out of an
item on the scrap heap - a CompuServe Tri-Node - it's a rackable box,
about 21" tall (twice as tall as an RX01, say), with *3* independent
Qbuses inside. The only cards I got were some CompuServe-branded
grant cards and one terminator each. I don't know how long ago it was
gutted, but it's been sitting on a pallet for months.
The front panel is in triplicate - three boot switches, three LTC
switches and three run switches. It has three power switches on
the back, and three watchdog boards inside.
*Dual* boot?!? Nay! Three OSes in one! I should have enough PDP-11
boards to have an RT-11, a 2BSD, and some thing else, all in the same
cabinet (external disks, naturally). I have plenty of LSI-11 and
KDF-11 boards, but not KDJ-11, unfortunately. If only there was a
DEC terminal with triple-session capability. Maybe I could rig up a
video switcher and use three VT240 bases?!? (I know I can switch the
RS-232 line, but that won't preserve screen contents of the other sessions)
... or perhaps three ports on a terminal server...
The only thing missing is the back door skin. It was apparently removed
some years ago, and none of the tri-nodes have them.
Should be a bunch of fun getting this guy running!
I have a photo copy of the AST I/O Plus II card user's manual. It is a
Serial Parallel, Clock and Game card. It is about 50 pages long and has
I will mail it to any one who needs it.
I was wondering, is all blank papertape media interchangeable?
I know that it can be made of paper or mylar,
and that it comes fanfolded and on spools,
but are there variations that would block interoperability,
like varying widths?
In particular, I'm wondering if any one can tell me if the
tape offered up on ebay at
will work in my friden flex-o-writer sps...
(for that matter, if anyone here can help me find sps user and
repair manuals, that'd be lovely... I'd like to know the pinouts on
the i/o ports on the side, and I need to repair one of the carriage
--thanks in advance
I've got a single EPROM file that I need to split into separate odd-byte/even-byte files for programming into two separate (smaller) EPROMs. I'm not able to figure out how to make the Unisite programmer do this, so I'm thinking a DOS or Windoze based splitting utility will do the trick.
Here's the problem; I've searched all over Google, and can't find anything that'll work.
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
ARS KC7GR (Formerly WD6EOS) since 12-77 -- kyrrin(a)bluefeathertech.com
"I'll get a life when someone demonstrates that it would be superior
to what I have now..." (Taki Kogoma, aka Gym Z. Quirk)
after checking in my IBM XT reference manual, the fact is that
they added a buffer to the normal data and address bus and sent
buffered these signals into J8. Also, they added a 14.318mhz
oscillator on the expansion chassis side because they did not
want pass this high of a frequency over the cable. This does
mean that the manin 14mhz and the expansion chassis 14mhz are
not in phase.
The added buffers make the timning in slot 8 a littl emore tight
because of the added delays through the additional chips. Slot
8 also had a requirement that it supply a card selected signal
back to make sure the card was really ready to be accessed.
The buffering from an engineering standpoint was done to increase
the drive on the cable to the expansion chassis as well as help
isolate the rest of the system bus from any added capacitance
and noise from the outside world.
best regards, Steve Thatcher
>--- Original Message ---
>From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
>Date: 4/2/03 12:36:58 PM
> > >But in the XT, one slot is different.
>> > Why?
>On Wed, 2 Apr 2003, Ethan Dicks wrote:
>> decided it was easier to give away a serial card than deal
>> customer-support issue of random 3rd-party cards not working
>Did they leave off the buffer chip BECAUSE the serial card didn't
>Or did they use the serial card to cover up a MISTAKE?
>Or did they have some OTHER plan for it, and used the serial
card as a
I managed to pick up a near-complete RS/6000 model 250 (7011-250) today,
complete with ram, disk, framebuffer, sound card, and video capture
card... A pretty neat thing to play with if it had a working power supply.
Does anyone have a spare that they would be willing to part with?
Purdue Universtiy ITAP/RCS
Information Technology at Purdue
Research Computing and Storage
>From: "Patrick Rigney" <patrick(a)evocative.com>
>> Old dry grease is quite common on these old drives, as
>> well as slight corrosion on the guide bars. You should
>> be able to relube and get it running, without changing
>> the stepper settings.
>> As I recall, the H89's came with one of the snail track
>> type positioners. The biggest problem would be the guides.
>Dwight, yes, the mechanism is very stiff, and I hope a little careful
>lub'ing may restore its health. Now that I think about, though, I wasn't
>very smart by trying as many diskettes as I did... hopefully I didn't
>strain/burn/damage the stepper during my experimentation.
You don't have to worry about the stepper. These draw almost
the same power if they are stalled or moving. Especially
at the slow speeds used for a disk drive.
>This drive is worm gear rather than snail track. It's one of the drives
>with the gigantic door that covers almost the entire face of the drive...
>Siemens FDD100-5. I think this is the drive that's original to these
>beasts, so I'd like to keep it alive if I can.
>From: "Patrick Rigney" <patrick(a)evocative.com>
>> [Tony wrote:]
>> Very odd...
>> You might try checkking the index monostables on the hard sector
>> controller (they only really do anything once per track, when the index
>> hole between the sector holes comes round), but I can't see why it would
>> then work for the first 4 cylinders.
>Well, as it turned out, the stepper motor on the drive was locking up. The
>further towards the inner tracks it got, the more it struggled, and it
>wasn't close to correctly centering over any track beyond the first few.
>I'll mess with that later. I was able to replace the drive with a spare,
>and I'm again up and running. I produced several good test boot disks, BUT,
>I don't know how well that new drive is aligned, it's straight off the shelf
>from the As-Is room at Wierd Stuff. Rotation speed is spot-on according to
>the internal diag, but I don't have a 5.25" alignment disk to check it
>otherwise. Anyone who receives a boot disk from me is, therefore, going to
>be my "canary in the mine." :-)
>Next task... get the soft-sectored controller running. Unfortunately I have
>no docs for this whatsoever, not even a schematic. I understand that it
>requires MTR-90, and possibly a certain HDOS software distribution as well.
>Does anyone know?
Old dry grease is quite common on these old drives, as
well as slight corrosion on the guide bars. You should
be able to relube and get it running, without changing
the stepper settings.
As I recall, the H89's came with one of the snail track
type positioners. The biggest problem would be the guides.