9 Oct
2003
9 Oct
'03
2:07 a.m.
Hello,
as for the "Line or Local" issue, you stated that the local side worked
fine. As in when
you type on the keys it prints what you type.
A rather simple test is to take a "fresh" 9 volt battery, find the two "RX
lines and connect
them to the battery, with the TTY in line mode the basket should quiet, if
it does, then
connect the keyboard leads between one side of the battery and the "RX" line
and try
typing again. If that works then your interface is lacking in the ability to
provide the
20/60 MA required by the TTY.
Jim
WB2FCN
----- Original Message -----
From: "David Gesswein" <djg(a)pdp8online.com>
To: <cctech(a)classiccmp.org>
Sent: Monday, October 06, 2003 9:51 PM
Subject: Re: ASR33 Teletype interfacing
From: Ian Primus <ian_primus(a)yahoo.com>
since I
One problem is that I don't know
what the Teletype is _supposed_ to do. I have never seen one
operational
Did you see my teletype page? It has movies of an operating teletype
http://www.pdp8.net/asr33/asr33.shtml Not too different than operation
in local mode.
I have been attempting to get my ASR33 teletype
connected to something
and communicating, but so far I have not been successful. I have built
the interface here :
http://www.daedalus.co.nz/~don/computing/20mahack.html
It looks pretty marginal, a lot of serial ports aren't going to have the
drive. I made a converter with optoisolators & rs-232 chips etc
which is a lot more complex than needed and also was a little strange made it before I got that degree. If nobody has
pointed you to a better
one
I can scan my schematic, >15 years ago radio shack
had the parts.
David Gesswein
http://www.pdp8.net/ -- Run an old computer with blinkenlights
Have any PDP-8 stuff you're willing to part with?