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Re: Apple IIc+ modem connector

Subject: Re: Apple IIc+ modem connector
From: "David Wilson" <mcs6502@gmail.com>
Date: 24 May 2006 07:40:49 -0700
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Michael J. Mahon wrote:
> Modems require both polarity supplies to do RS-232 signalling.  I'm
> sure you'll find +5v on the connector, too.

No, according to the Tech Ref Manual (page 406) the signals on that
connector are:

1 -5V
2 RxD
3 TxD
4 DCD
5 DTR
6 DSR
7 GND

Note: All signals except -5V and GND are TTL levels.

Even the circuit diagram (sheet 7) lists it as -5V (generated on sheet
2 from the -12V supply via a 200 ohm resistor and pin 7 of the VID
HYBRID circuit).

Follow-Ups:
- Re: Apple IIc+ modem connector
  - From: "Michael J. Mahon" <mjmahon@aol.com>

References:
- Apple IIc+ modem connector
  - From: rg.jones@rogers.com
- Re: Apple IIc+ modem connector
  - From: "Michael J. Mahon" <mjmahon@aol.com>

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