NCR model 3401 class 5451

From: R. D. Davis <>
Date: Sun Jun 18 11:20:40 2000

Greetings, is anyone here familiar with an NCR model 3401, class 5451
"application processor"? On a hand-written label on the front of the
machine there's a description of the memory in it: 8MB, 145ns. This
box has the following switches on the front panel, in addition to the
power switch:

Station ID (two thumbwheels)
Load options:
   primary OS/alt OS
BCD restart/system reset
diag port: on/off
mode: normal/diagnostic
ps margin: +5%/normal/-5%

On the back of the machine are the following connectors:

LS link (low speed link?): pos 0, pos1, pos2 (9-pin)
Diagostic port (25-pin - RS232 port?)
System bus: channel A, channel B (9-pin)
HS link (high speed linl?): pos 4, pos 5, pos6, pos7 (9-pin)

One interesting thing about this system is a board labeled "writeable
control store" - does anyone know it this is user microprogrammable?
On this board are about 45 AMD (I think) 8648 ICs and about 27 8651
ICs, in addition to what I think may be EEPROMs (Fairchild MB7142H),
as well as morotola 8644A, 8644B, 8648 and 8649 chips and a few other
ICs. Attached to this board is a other board that is apparently the
main part of the CPU with about 6 (from what I recall) square ICs,
about 1" square, with heat-sinks that I haven't figured out how to
remove yet to see the part numbers.

Did anyone here purchase the machine like this that was listed on

Another apparently related NCR box that appeas to connect to the SMD
drive only has the following indentification on it: "class
H6830-STD1-01-46." Coming out the back are three cables: one that
looks like it's got about 50 conductors in it, and two that appear to
have about 20 to 25 conductors (these are just my guesses, haven't
counted them). There are also two 50-pin connectors. I think this
connects to the hard disk, but I can't figure out how, or if, it
connects to the model 3401.

Is anyone here familiar with the above equipment?

R. D. Davis             
R. D. Davis             
Received on Sun Jun 18 2000 - 11:20:40 BST

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