On Sat, 21 Nov 2015, Steven Hirsch wrote:
I purchased one of these units on eBay and it seems to be working - modulo a
few early-80s tantalum caps that went up in smoke.
The tester relies on an attached printer to record test results, which are
displayed only fleetingly on the front-panel display. Unfortunately it did
not come with the printer and I cannot find any information on line.
Does anyone have information on this? Is it serial? Parallel? The onnector
is a 20-pin, 0.1" DIP header on the rear panel. The tester supplies printer
power on a small 3-pin Molex connector.
I can probably trace this out on the internal logic board, but thought
perhaps another list member owns one of these and can elaborate.
I'm also trying to find the manual appropriate to a base Model 723 tester.
The one floating around on the net is for an upscale model (723-4M). While
there are a number of similarities, I'm running into just enough behavioral
difference to make it worth finding the correct docs. There's also a
programming and setup "worksheet" document that has not surfaced anywhere.
Update: With a bit of patience I have figured out the printer interface.
It uses a parallel printer and presents the following pinout on the 20-pin
rear-panel header:
1 Gnd
2 n/c
3 +15V Reg
4 Gnd
5 D6
6 D5
7 D4
8 D3
9 D2
10 D1
11 D0
12 Gnd
13 Strobe* (Out)
14 Gnd
15 Gnd
16 Gnd
17 n/c
18 n/c
19 Busy (In)
20 Gnd
I have no idea why there's a +15 supply. Note the 7-bit interface.
Maybe someone will find this useful.
Steve
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