[GreenKeys] Interfacing to the HP 2752A (ASR33)...

[Clay Archer]

I have a Teletype ASR33 that has the HP 2752A modifications.   Has
anyone had any experience connecting one of these?    With some research
and tracing out the modifications, it looks like HP added a circuit
board (part number 02752-6001) which adds a "Read Command" to start the
tape reader with a remote signal.  I found a document showing the I/O
pins for the 2752A which has "Input Data Bit, +12V, -12V, Output Data
Bit, Read Command, and Ground".   The current loop Input + (Terminal
strip 3) and Current Loop Output + (Terminal strip 7) are fed to the I/O
connector as "Input Data Bit" and Output Data Bit", however the Current
Loop Input - (TS 4) connects to the +12V input, and the Current Loop
Output - (TS6) connects to "Ground".   I'm not sure what if any other
modifications have been made to the ASR33.

 

Can I just connect it as though it's a standard current loop interface,
should I remove the HP modifications, or should I adapt or create an
interface that supplies the +/- 12V supply?   Just trying to avoid some
smoke...;-)

 

Clay Archer

 

 

 

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