What's a Xerox 83D?

From: Lawrence Walker <lwalker_at_mail.interlog.com>
Date: Thu Feb 12 01:00:11 1998

On 15 Feb 98 at 19:14, Tony Duell wrote:

> I went to a radio rally (hamfest today), and I got a machine that I know
> nothing about :-). The other stuff I got isn't really appropriate for
> this list.
> Anyway....
> The machine is a Xerox 83D (or at least that's what it says on the
> nameplate) - I can find no other markings on it, and it appears to be a
> workstation of some sort.
> It's a brown plastic tower case, a little larger than a large PC tower.
> It's _very_ modular. On the back there are 5 blanking plates the full
> height of the cabinet, with 5 slots behind them. They contain, from the
> left :
> Module C1 - DCM (Display Control/Memory?). This board contains 1Mbyte of
> parity memory, some TTL chips to support it, 18 off MB8266 (video
> memory?), 3 gate arrays (no idea), and 2 xtal oscillators. There's a 15
> pin D connector on the bracket that's labelled 'Display'
> Slot C2 is empty.
> Module C3 - MPB (Main Processor Board?). There's 4 off 7C901's
> (high-speed 2901 bit-slice ALUs), 12 MB8168s (control store RAM?), 2 more
> gate arrays (sequencer and something else?), 4 off AM9122 (register
> RAM?), some TTL glue, a 32MHz clock can, an 8254 counter/timer chip (!),
> sockets for more control store RAM, etc. On there bracket there's a
> DC37-P connector marked 'Bus Expansion' that seems to be linked to more
> empy sockets - probably for buffers.
> Module C4 - IOP (Input/Output Processor?). This one is full of random
> chips. There's an 80186 CPU, some EPROM, an 82586 ethernet chip, an 8272
> disk controller, an 8251 USART (keyboard port?), 3 off 8259 interrupt
> chips, a hard disk controller based on the 8X305 controller, a lot of
> TTL/buffers, etc. There's 5 connectors on the bracket - from the top :
> DA15-S 'ethernet', DC37-S 'floppy', DE9-S 'keyboard', and 2 DB25-S RS232
> ports (Comm and Printer).
> Module C5 contains a smaller PCB called an LPO (Laser? Line? Printer
> Output?). It's fot a few TTL chips and PALs on it, and a single DC37-S
> connector marked 'printer'.
> To the right of the cardcage there's a plastic door that folds down.
> Behind it are 2 more modules - C6 is the power supply (which goes through
> to the front of the case, and also carries the power switch), while C7
> is the hard disk. That's a standard 20Mbyte Seagate ST506-like unit (an
> ST225 or something) on a bracket.
> The monitor is monochrome, and about 17". It connects to the display
> connector on module C1 and also to the keyboard connector on C4. There's
> a 5 pin DIN socket on the base of the monitor for the keyboard (which I
> don't have). There's also a beeper in the monitor base.
> I've also got 2 modules that seem to stack on top of the unit, and
> connect to the 'floppy' connector. One contains a 5.25" floppy drive (no
> idea as to the density, etc). The other contains a QIC tape drive, which
> seems to have a floppy interface. I can provide module numbers of the
> mecahnisms if it would help.
> Any ideas as to what it is, and where to find a keyboard for it?
> -tony
 And I thought I had problems trying to get this TRS-80
model II with 8' disks working. :^)) Damnnnn. !
 Is confronting the problems one of the allures of collecting
old mchns. ??

ciao larry
Received on Thu Feb 12 1998 - 01:00:11 GMT

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