31 Oct
2004
31 Oct
'04
12:28 a.m.
Hi Scott,
Nice pictures. I'm in the process of creating a photogrpahic catalog of
all the Multibus cards that I can get my hands on. Do you mind if I use
your pictures and dscriptions? I have so many loose cards to do that I
never got around to taking the cards out of my MDS 235 and photographing
them. More below.
At 12:02 AM 10/31/04 -0500, you wrote:
This weekend I had the time to pull open the Intel MDS
system I
mentioned last week, and record info and photograph all the Multibus
cards. I've put the info up on some personal web space. All are
invited to comment on and advise me on what I've got.
The URL is: http://sasteven.multics.org/MDS/Intel_MDS_Cards.html
Here's the 'text' of the page, which includes board numbers, etc. (go
to web page for a photo of each board)
----------------
64k is correct. It sounds like you have a model 225 with the Integrated
Processor Card with the 8085 CPU. The 225, 226 and 227 models came with an
IPC (Integrated Processor Card). It has a 4 MHz 8085A-2 CPU and 4 K of ROM
and 64K of RAM. All other (22x) models came with the IPB (Integrated
Processor Board). It has a 2.6 MHz 8080A-2 and 4K of ROM and 32K of RAM.
See <http://www.classiccmp.org/hp/mds.htm>.
These boards are out of my MDS system. It was
targeted as an ICE for
the 8051 microcontroller. The emulator POD plugs into one of the board
sets below.
This page is organized to document the boards as they are installed in
the Multibus cage from the bottom going up.
---------------------------------
Bottom Board on Rack-
Floppy Disk Interface
Double Density
PWA 123857-002
S/N 023767
This board has a cable plugged into it's top edge connector.
---------------------------------
Next Board Up
Floppy Disk Controller Channel
PWA 10000457-05
(may have copied down one extra 'zero' in above part number)
This board does not have a cable plugged into the 'top' edge connector.
Edge connector shows 'weathering' from not having connector on it.
---------------------------------
Next Board Up
Trace Board
PWA 162249-001
S/N 13904
J10 and J11 headers which are brought out to the Emulator Pod.
---------------------------------
Next Board Up
Controller Board
PWA 162380-005 Rev M
This board has an 8080A Processor on it.
The Multibus P2 board edge is 'bridged' to Trace Board (above) on a
two-slot interconnect board.
Has header on it brought out to Emulator pod and also power header to
emulator pod.
---------------------------------
Open Slot, second from top.
---------------------------------
Top Board
I.P.C. board
PWA 123192-003
S/N 084111
This board has an 8085 Processor and array of memory chips.
Also has two 8251 and two 8259 chips.
Board has row of buttons to generate interrupts that faces out to front
of system.
It appears I have here an 8085 based system. Is this correct. It
also appears that there's an 8080 controller as part of the emulation
system. I'm assuming (?) the system would run with the Emulator
boards (Trace Board and Controller Board) not installed.
Some questions:
1. Is the memory array on the top board (board with 8085 processor)
the main system memory. It looks like four rows of 4116x8, for a
total 64K.
2. The system has a built in CRT display, and a keyboard input.
Where is the video generated and keyboard I/O circuitry?
On the IOC (I/O Controller) board that stands vertically in the back of
the machine. It handles all the system IO except for the Interrupt, Run and
Reset Switches which are on the front panel and plug directly into the CPU
card and the interface to the ICE and Trace pods.
Joe
Any and all insights into this system are welcomed. Probably I'll add
in any info I receive into the HTML for the page.
Thanks,
Scott