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Old 07-28-2009, 11:19 PM
Geoff Harrison Geoff Harrison is offline
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Quote:
Originally Posted by TomL_12953 View Post
Does this mean my TTY would've worked???

Tom L
Well, with the diodes installed as per the silkscreen, no input signals were getting through to the UART. After I rotated them, the input was getting through,

but...

the pulses arriving at the UART are very messy (see the scope trace below) and I'm not sure why. The UART can't handle it. I'll play with it a while longer, but I think it makes most sense to convert it to RS232. As you said elsewhere, it will make for a more versatile interface.




The bottom trace is the input to IC K pin 9, which is supposed to be more or less TTL, the top trace is the output from IC K pin 8, which should be a clean TTL square wave.

Geoff.
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