Ithaca Audio and friends

From: Doug Yowza <yowza_at_yowza.com>
Date: Fri Mar 27 01:44:00 1998

On Thu, 26 Mar 1998, Tony Duell wrote:

> At a guess, the 50 pin ones are parallel I/O ports and the 26 pin one is a
> serial port (you mentioned the 8251, which is a USART chip). Try tracing
> grounds and then signals (maybe to 1488's and 1489's)- you may find that a
> straight IDC cable will link the 26 pin connector to a 25 pin serial port.
> Don't plug it in without checking, though.

Your guesses seem correct about the function of the connectors, but I'm
not so sure about the mapping of the 26-pin connector -- they seem like
they might be reversed from what I would expect. Here are a few I buzzed:

26 - gnd
25 - transistor Q1
24 - 1488.1 (Vee)
14 - 1489.4 (2A)
13 - 1488.2 (1A), 1489.14 (Vcc)
5 - 1488.6 (2Y)
4 - N/C
3 - 1489.13 (4A)
2 - N/C

This means very little to me, other than I vaguely recall that the 1488
and 1489 are drivers (and I found a pin-out for them on the web), and I
expect ground, TX, and RX on the first three pins.

-- Doug
Received on Fri Mar 27 1998 - 01:44:00 GMT