On Aug 31, 18:59, Erik S. Klein wrote:
> I just received one of William's ASR33s and it appears to be in good
> working order. I am not at all familiar with these machines so I have a
> few questions about their operation and interfacing.
>
> First off, when I power on this unit the "main" motor doesn't run. It
> turns when moved manually, but it won't move by itself. Depending on
> the motor position at power-up (I think) I sometimes hear what sounds
> like a warning buzzer. Is there something I'm doing wrong? How would I
> run this machine in "local" mode?
Sounds vaguely similar to a problem I have (occasionally) with mine.
Sometimes the motor noise starts to rise and fall slightly, as if the
motor is struggling; eventually it blows the fuse. In my case, I suspect
the problem is something binding (needing adjustment) and/or needing
correct lubrication. There are lots of parts that need lubrication, and
it's definitely NOT a case of oiling or greasing everything in sight!
There should be a knob on the front right. Turn left for online, centre
off, right for local.
> Once I figure out that this machine is working (I assume the problems
> are mine and not the machines) I'd like to hook it up to my Altair
> (which is now running great thanks to Dwight!). How would I go about
> doing this? I'm guessing I'll need some sort of box to interface
> between the TTY and RS232, but I haven't yet found any information on
> that. Can anyone point me to an article, website or some other source
> of information on this?
You'll need a couple of RS232-to-20mA current loop converter circuits, one
for the Tx line and one for Rx. Usually a small power supply, a couple of
opto-isolators, and just a few other components.
> What am I missing? Is there anything else I should know?
Probably ;-) But I'd get the machine working in local mode before you
start worring about interfacing it. David Gesswein's excellent site at
www.pdp8.net has the ASR33 manuals in the document archive.
--
Pete Peter Turnbull
Network Manager
University of York
Received on Sun Sep 01 2002 - 03:59:00 BST