Subject: Re: VT220 connector pinouts
To: Matt Thomas <matt@3am-software.com>
From: Robert D. Keys <bsdbob@seedlab1.cropsci.ncsu.edu>
List: port-vax
Date: 09/28/1998 14:48:50
> No he isn't.  VT220s have DB25 and 20ma current loop
> connectors.  No MMJ (like the VT320 or VT420).
> (As I said, I have one and I am using the DB25 port).

And for sure.... be careful not to get a 20ma loop on RS-232 lines.

Alas, I did that on my very first machine, and it blew the board
traces like fuselinks..... expensive ouch, 20 years ago.

After that I went strictly to 3 wire hookups since some manufacturers
used odd leftover pins on RS-232 lines as 20ma loop lines.  3 wire
RS-232 hookups are usually guaranteed to work, and don't have loop
voltages loose on the pins.

Good LUck......

RDK