Help needed: AS33 understanding Reader Run Control

From: Gerold Pauler <>
Date: Tue Feb 3 21:04:44 2004


in the process of restoring one of my teletypes I decided
to connect it to a PC. Send and receive work fine, but the
tape reader does NOT work in line mode (local is no problem).

It is an ASR33 relabeled by HP and has a HP Reader Run Control Card.
I have put a schematic of this card online
(Couldn't figure out the types of T1 and D1 - so these can be a pnp or
a zener diode also. Polarities of reader run signals (RDR+/RDR-) can
also be wrong.)

But I am too dump to understand how to connect the reader run signals.
I'm not even sure what levels they should have.
I just thought that a circuit identical to TX (on PC side aka RX on
teletype) should do.

If you need additional infos to help please let me know.

        Gerold (
Received on Tue Feb 03 2004 - 21:04:44 GMT

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