The way the PS/2 keyboard is handled has always been something we were never quite happy with. The key points being: The PS/2 controller had no way of signalling that there has been a new keystroke, the buffer had to be polled via SPI. The PS/2 controller had no way of talking to the keyboard and had to rely for the keyboard to initialize itself properly. Also, typematic rate and delay could not be set, as couldn’t the states of the keyboard LEDs.
Frank van den Hoef, who is adapting the Steckschwein SPI & FAT32 code for his tiny65 machine made me aware of a classic mistake for a 6502 assembly coder to make. Namely in our sdcard driver, when waiting for the “proper” response from the card (which should have bit 7 cleared). The routine handling this looked like this: 1 sd_cmd_response_wait: 2 ldy #sd_cmd_response_retries 3 @l: dey 4 beq sd_block_cmd_timeout ; y already 0?