11-01-2021, 01:09 PM
Okay, I've identified the modifications I should do on this Microbee 32:
[1] Revised cassette interface
[2] Removing white flickers - ground pin 4 of IC16
[3] Stopping noise on the RS232 RXD line - add 18kΩ resistor
[4] RS232 output circuit TXD - change 3.3kΩ to 18kΩ
[5] Modify NET ROM from 2532 to 2732 and add Pascal (if I have a 2732 handy)
For [1], it says to move C23 to TP8/9 ... I don't see any TPs labelled on the board ... can I just put it in parallel with R24?
Going to skip the 13.5MHz and dual font ROM changes.
[1] Revised cassette interface
[2] Removing white flickers - ground pin 4 of IC16
[3] Stopping noise on the RS232 RXD line - add 18kΩ resistor
[4] RS232 output circuit TXD - change 3.3kΩ to 18kΩ
[5] Modify NET ROM from 2532 to 2732 and add Pascal (if I have a 2732 handy)
For [1], it says to move C23 to TP8/9 ... I don't see any TPs labelled on the board ... can I just put it in parallel with R24?
Going to skip the 13.5MHz and dual font ROM changes.