18 Jun
2013
18 Jun
'13
11:48 a.m.
Timely discussion - just last week Rob and I here in Vancouver got a
Model 28 teletype working and printing from a computer, in
preparation for a film production request.
The 28 teletype we are using has gears for 75 baud, so that's what we
needed to send (with 5 data bits and 1.5 (minimum) stop bits).
That's touvched a nerve with me. Almost all my 5-bit stuff is 50 baud
apart from my Creed 444 (aka 'Telperinter 15') which has 75 baud gears in
it. To convert it would be trivial if I could get the gears. But it looks
like I will ahve to cut them myself, and they are skew helical gears.
What fun...
Rob brought along 3 serial converters, 2 of them wouldn't work for
some reason or other, but one successfully drove the 28. It's a model
GUC232A, and appears to be still available from Iogear.
I just did some further tests of the serial converter, observed on a
scope with the following outcome:
Requested Result
BPS
--------- ------
300 - good
150 - good
134 - produces 9600
110 - produces 9600
75 - good
50 - invalid-value error at runtime
Thers's a nice little project for somebody (given that USB is claimed to
be simple). Make a device with a USB port on one side (and which behaves
like a normal USB-RS23s converter) and which will do the slower baud
rates (it needn't go above 9600), including 110 and 45.45 baud.
-tony