9 Dec
2012
9 Dec
'12
9:05 p.m.
On Sun, Dec 02, 2012 at 10:46:30AM -0500, Michael Thompson wrote:
I am not sure if this configuration can be duplicated on one of the
emulators. If someone could try the monitor installation and
subsequent loading of programs from a real "Teletype" it would be
interesting to see if it works. If it does work, then maybe we need to
add the reader control circuitry to the 20mA/RS-232 converter that we
are using to connect a PC to the PDP-8/I.
This may be OBE but I finally got time to test and to fix the PDP8
so I could test. The first attempt corrupted my DF32.
I tried using the DMS load command sending pip from PC to a DF32. It
failed if I turned off hardare flow control. I have a board which converts
the current loop to RS-232 and the reader run into CTS. I was running at
9600 baud.
I wasn't sure if the DF32 could complete a write in the 100ms between
teltype characters so used the higher baud rate.
The common USB serial devices do flow control fine but won't do 110 baud.
Real 16550 will do 110 but the flow control is in software so the fifos
have to be disabled. With vista it seemed to need a reboot after
disabling the fifo in device manager before it took effect. I haven't
figured how to disable them under a recent linux.
FYI: I have made a version of my dump and restore that may work with
TC01/TC08. The person I made it for hasn't had time to try after I made it.
Its only been tested with an emulator since I don't have a TC01. If you have
a use for it it's here. See readme.txt. The TC01 files are in tc08.zip.
http://www.pdp8online.com/ftp/software/dumprest/
At 110 baud it may not be too useful. I stick a TTY clock card with the
cap value changed in my 8/I to run at a faster baud rate.