9 Jun
2005
9 Jun
'05
6:57 p.m.
To get it short: I went, and finally got two HP PSI
-> X.21 cables, 5 m
each. Issue solved. Now to learn something about X.21, and/or communications
standards in general... Any good sources Google won't turn up likely?
I know nothing about it,and the offiical atandard is likely to be
expensive :-(
Somewhere I have something called a TAXER, which appears to be a bit
error rate tester for an X21 link. It's a rather nice portable instrument
with a 64180 processor in the middle of it (got it at a radio rally for
not very much...) I also have some kind of comms bridge. It's got a 68K
processor IIRC, a floppy drive on the front, and X21, X25 (at RS232
levels) and Ethernet connectors on the back. They're on separate plug-in
boards that connect to the main logic board, there's a 48 pin socket on
the mainboard associated with each comms card that holds a 8390 ethernet
chip for the ethernet interface and a specially-pinned-out (I suspect)
COM5025 (?) serial chip for the other 2 interfaces.
You've just reminded me to dig this stuff out and have a play...
-tony