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ASR43 TAU Help

NeXT

Veteran Member
Joined
Oct 22, 2008
Messages
8,143
Location
Kamloops, BC, Canada
I have a model 43 teletype which someone previously pulled the Terminal Auxiliary Unit (the thing that converts the line in to CMOS digital levels) and kludged in a current loop adapter. I want to add support for both current loop and serial again but while I can find the diagrams for the board they list the components with Teletype part numbers. Does anyone have a cross reference or will I need to do a bit of reverse engineering of their numbering?

TAU1_b.png

TAU1_a.png


474032 - 74LS32 - Quad 2-input OR gate?
474008 - 74LS08 - Quad 2-input AND gate?
 
Okay I think I figured that parts list out by guessing what it might be.

474032 - 74LS32
474008 - 74LS08
404049 - CD4049
335529 - MC1489
335528 - MC1488
335522 - 4N33
326800 - 4N33

Technically the optoisolators are something entirely different but you can sub in 4N33's and you should be fine. The only other one I was a bit hung up on was the MC1489. It's an EIA-232 receiver, the pinout of the chip matches the schematic but it has "Response Control". Presumably it's for noise filtering or setting the threshold so I'm not sure if those pins were omitted from the schematic or this isn't the correct part.
 
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