16 Apr
2011
16 Apr
'11
9:31 p.m.
On 4/16/11 5:59 PM, B Degnan wrote:
I have been able to get my PDP 11/05 to print
"hello world" by entering
a short program into the toggle switches. I can simultaneously get the
punch to print if I enable it. The text is actually garbled
(TE]HJVYRTD), but I assume I just have to make an adjustment to the
parity/stop bits or related. At least it's consistent.
Excellent!
But the reason I am writing is to see if I can help
with the reader.
When I load and run the bootstrap loader the reader does not attempt to
read a bootstrap tape either automatically or by pressing start. I think
that's because the reader is not getting power.
I can't get it to do anything in local mode or line mode.
I have painstakingly traced the wires to get a good idea of the
modifications made to the reader control. It appears that two of the
wires coming from the reader are diverted to run through a 24V
transformer (?) with a 0.5 uF 47 on top that is part of the reader
control mod, and then exit the teletype .
...
I must be close. I read that there was a power supply
for the reader on
some asr 33's, Do I need a 24V power source for the reader?
The power supply for the reader in an ASR-33 is in the base, mounted
near the top. A good picture of it can be seen here:
http://www.pdp8.net/asr33/pics/old_rdr_power.shtml
I gather from your pics that you're running your ASR-33 baseless?
-Dave
--
Dave McGuire
Port Charlotte, FL