TRS-80 Model 100: Phone port pinout

From: Tony Duell <>
Date: Fri Feb 4 19:16:43 2005

> Does anybody have a pinout for the phone port on a TRS-80 Model 100?


It apperas this is an 8 pin 'offset' DIN socket. And from the PCB layout,
it appwears the pin numbering is :

Round the outside (clockwise from the keyway) 7 1 4 2 5 3 8, with 6 in
the centre (this is _NOT_ the same as the normal 8 pin 'circular' pinout)

The signals (from the schematic) are :

1) One side of Telephone
2) Ground
3) Other side of telephone _and_ line
4) Rx signal inout from accoustic cups
5) Tx signal output to accoustic cups
6) Vdd (+5V power for accoustic cups)
7) One side of line
8) RP (general purpose input, maybe for a ring detector that never existed)

Assuming you're wantign to direcectly connect it to a phone line, connect
the line between 3 and 7, the phone between 1 and 3. There was a socket
that shorted 1 and 7 that yuo connected in place of the M100 when the
latter was removed so you could still use the phone.

Received on Fri Feb 04 2005 - 19:16:43 GMT

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