Quick update. I built a rudimental PET video mixer according to D'asaro schematics to test if the main board was working correctly. The discrete components I used don't match exactly the ones on the schematics (resistors and capacitors are a little off), so the result is that the external monochrome monitor I'm using as test is not syncing correctly on the video signal. Still, I'm able to see some output. When I turn on the CBM, I see a mostly green screen, followed by a black screen, followed by what seems to be a single line of text that is repeated multiple times on the screen and that keeps oscillating in a diagonal fashion. I'm not entirely sure of what I'm seeing, but this seems to suggest that the video generation circuitry on the main board is doing something, and that there is some processing going on (could it be the BASIC prompt?). I may try to build a better one in the next days if I can find the right components. I will now try to refresh the solder joints on the diode bridge, on the capacitor and on the LM7812 rectifier and see if I can get the heater of the internal monitor working (and/or if this leads to some difference in the measurements). -- Sent from: http://cbm-hackers.2304266.n4.nabble.com/ Message was sent through the cbm-hackers mailing listReceived on 2018-02-25 19:03:30
Archive generated by hypermail 2.2.0.