🚀 go-pugleaf

Can anybody help with information about a National
Semiconductor memory board for a PDP-11?
It's a hex-height MUD-slot 1/4-megabyte module, 
with one parity bit per byte. It's currently populated to 
64k. It appears to support 22-bit addressing. 
The DRAMs are 4116s.

There are about 20 jumpers and 3 8-way dip-switches.
There are also 2 LEDs at the front (handle) edge of
the board: one red, one yellow.

I've managed to suss out a certain amount about it
by track-tracing, but the board is multi-layer, and it's
murder on the eyes. The following numbers appear on the
board (some of these are hand-written in what looks like
tippex fluid, so I may not have read them exactly right):

	[component side]
	Assembly No. 98010 3841-D07 REV J
	     	1042 [might be 1D42]
	S/N PL001-054

	[solder side]
	PCB 551103841-001 

Date-codes on the chips suggest that it was made around
1982. 

Essentially, I'm looking for any information about setting
the jumpers/dip-switches, though a full circuit diagram
would be ideal.

I've tried getting in touch with Nat Semi: apparently,
the division of the company that made these boards was sold
off to Hitachi, who claim never to have heard of it.

I'd be very grateful for any help with this! Email me with
anything you've got.

James
-- 

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James Lothian        |      "It's life, Jim, 
james@uk.ac.ed.caad  |   but not as we know it"