Systems Enhancement Corporation Power Administrator 800

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Fri Jun 6 17:13:09 2003

> Of course there is no "standard" 9-pin serial connector, except what has
> become standard just by virtue of mass usage on the PC. The original IBM PC

Agreed. Around the time of the PC/AT, several other manufacturers used
DE9s for the (cut-down) RS232 port. Often, pins 2-8 had the same
functions as on the DB25, with pins 1 and 9 of the DE9 being DTR and RI
in some order.

The HP110 ('Portable') and Portable+ do this -- here's the wirelist of
the serial cable I made up for my machines ..

HP110 RS232 DTE
DE9-P DB25-P

     Shield-------------o 1 Prot Gnd
1 o---------Br----------o 20 DTR
2 o---------R-----------o 2 TxD
3 o---------O-----------o 3 RxD
4 o---------Y-----------o 4 RTS
5 o---------Gn----------o 5 CTS
6 o---------Bu----------o 6 DSR
7 o---------Pu----------o 7 Sig Gnd
8 o---------Gy----------o 8 CD
9 o---------Bk----------o 22 RI


> which the PC didn't have (as far as I'm aware). I've never seen an RS232
> comms link fully populated and used to the standard though!

Nor have I. And also most manufactures totally abuse the handshake lines
-- you're not supposed to use them for flow control, for example. Watch
out for manufacturers who attempt to adhere to the standard here -- their
devices work with almost nothing else :-). And I'd love to know what the
designer of the HP82164 was thinking of -- some of the features of that
device are plain _crazy_!

-tony
Received on Fri Jun 06 2003 - 17:13:09 BST