Hi Guys
I have a pair of Commodore Amiga CD32 retro consoles, So that makes me cool right there
I noticed tonight making a serial cable (for receive only) to debug a microcontroller project,
there is voltage between the serial Rx pin and Ground pin whether the serial port is open in software or not.
The port does work as expected, but the Rx pin can light an LED quite well via a 470R current limiting resistor.
Then I tried my other identical console and it was the same!
Does anyone have an explanation for this? I have to have the pins correct because data is received on the Rx pin fine.
The console can run the normal OS like other Amigas, and I use terminal software often for debugging micro projects.
It’s a 5 Volt port, not RS232, or any negative levels. Transmit from the console is simply on & off.
Cheers
EDIT,,, There’d be a better section for this, but I couldn’t delete it myself.
Edit again,,,
Maybe it should be moved to the beginner section.
Hmm, why would you want to normally hold a pin high to stop it floating low and getting noise on it...