Computers with ports coming out the front?

From: Feldman, Robert <>
Date: Tue Dec 17 08:16:00 2002

Yes, pin 7 of the modem port is for +12V. The pinout of the DE-9P (except
for some early boards with a female DE-9) is:

1 Gnd
3 (not used)
4 MSB (Modem Status Bit)
7 +12V
8 MCB (Modem Control Bit)
9 RI

The Tech manual goes on to say all signals are TTL, and the interface is
"extremely vulnerable to damage through misuse." Also, some modems with
RS-232C connectors need an external adapter box so that the OI isn't

modem port Bob

-----Original Message-----
From: Gary Hildebrand []
Sent: Monday, December 16, 2002 11:33 PM
Subject: Re: Computers with ports coming out the front?

Lawrence Walker wrote:
> Yup, the whole shebang. External Battery, keyboard, printer, video,
> serial RS232 and Modem. BTW what was the difference between the
> modem and RS232 ports ?
> Lawrence

Besides number of pins . . . .

I think the 9 pin Modem port was for the accessory modem and has DC
feeding the box that fits in the disk bay. The RS232 could be
configured to drive a serial printer which was the common interface back
then, especially on daisywheels.

Gary Hildebrand
St. Joseph, MO
Received on Tue Dec 17 2002 - 08:16:00 GMT

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