Boot monitor with software-only xmodem and sd card loader

[tius]

I wish you all a happy new year, especially with good health!

I just released bootmon65 on github (https://github.com/tius/bootmon65). It's a small bootmonitor designed for a minimal 65c02 system (tiny65). However, some parts of it might be useful for other systems as well.

• - Fast software-only serial interface (57600 baud @ 1 MHz CPU clock) with full XMODEM support.
  - Minimal SD card loader for FAT32 formatted SDHC cards (up to 6 KByte/s @ 1 MHz CPU clock).
  - Simple monitor program with the usual commands for memory and register access.

The hardware requirements for the basic functionality are minimal. Only a few free I/O lines are needed for the serial interface and the optional SD card interface.

A lot of know-how gathered on 6502.org has been incorporated into the code. Many thanks to all those who have contributed and continue to contribute! Bug reports, comments and improvements are very welcome.

[BigEd]

Excellent! Thanks for sharing. I do like bit banged serial.

[tius]

BigEd wrote:

Excellent! Thanks for sharing. I do like bit banged serial.

Thank you very much @BigEd!

I would like to emphasize at this point that some of the optimizations there are based on the ideas of other developers. I'm sorry if, after many years, I sometimes can't remember where I first saw one trick or another.