9 Nov
2020
9 Nov
'20
5:53 p.m.
On 11/9/20 5:36 PM, Joe Piche via cctalk wrote:
Hi All.
Hi,
The VT320 only has the DEC-423 MMJ, no RS-232.
I /thought/ that Modified Modular Jack was simply a physical thing and
completely independent of Recommended Standard 232.
Every MMJ that I've run into has had RS-232 run through it perfectly fine.
I found a number of guides that show how to wire up
the DEC-423
connector to a DB-9 RS-232, but so far I have struck out. It will
receive text from the remote computer, but I do not see anything on the
remote when I type on the VT-320.
Can you enable local-echo on the VT-320? If you can, do you see
anything appear there when you type?
I have loop backed the TX to RX on the VT-320
terminal, and it does
work. TX=RX Baud rate? in the VT320 settings, and the data bits, parity,
& stop bits match.
What, if any flow control is in use?
DEC-423 (lock tab bottom right, pin one on the left, 6
on the right)
1??? DTR
2??? TXD
3??? TXD-
4??? RXD-
5??? RXD
6??? DSR
For a cross over cable:
423 #2 goes to DB9 #2 (TX to RX)
423 #3 & #4 to DB9 #5 (TXD- and RXD- to GND)
423 #5 goes to DB9 #3 (RX to TX)
423 #1 to DB9 #6 (DTR to DSR)
423 #6 to DB9 #4 (DSR to DTR)
Does this look like it should work? It does leave DB9 RTS and CTS
unconnected.
That would likely be a problem for hardware flow control.
Thanks!
Good luck.
--
Grant. . . .
unix || die