Questions about TRS-80 Expansion Interface

From: Louis Schulman <>
Date: Thu Jan 18 16:59:37 2001

Well, there is no RS-232C port with the basic interface. This requires
a card to be installed in the bay on top of the interface. If you have
this card installed, the signals appear at the "Expansion Board Card
Edge" which is in the middle of the front of the interface.

The card edge is 40 pin. The following are the main signals an pins:
18-TD; 20-SGND; 22-RD; 30-CD; 32-CTS; 34-DTR; 36-RTS; 38-RI; 40-DSR.


On Thu, 18 Jan 2001 10:21:23 -0800 (PST), Vintage Computer Festival

*I need to know where the serial port connector is on a TRS-80
*Interface. I have two of them. One has its ports labeled, and one of
*ports is labeled "MODEM" but it is simply an edge connector. Is this
*serial port? If so, what's the pinout?
*Any help would be greatly appreciated. Thanks!
*Sellam Ismail Vintage Computer
*International Man of Intrigue and Danger
Received on Thu Jan 18 2001 - 16:59:37 GMT

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