15 Nov
2014
15 Nov
'14
9 p.m.
On Sat, 15 Nov 2014, tony duell wrote:
Yup, I was thinking 1488 and 1489. I guess there wouldn't be a 1489 on
there if they were using a 1458 as a level converter.
It sounds like
you've just about got it figured out though. If you have
the datasheet for the 1458 (aren't there 1459s on the board too?) then
you can follow the signals through the level converters back to the
UART, and its datasheet should then tell you exactly which signals are
which.
Are you not thinking of the 1488 and 1489 (commonly used RS232 driver
and receiver chips)? The 1458 is a dual op-amp.
Op amps were often used as level shifters in older RS232 devices. I
guess that's what is happening here.