3 Feb
2004
3 Feb
'04
1:04 p.m.
Hi,
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
http://pdp8.de/download/HPtty.pdf
(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.
TIA
Gerold (pdp8.de)