This is impressive considering the lack of technical info available about the machine. I'm currently adding M23 emulation to MAME, with ROMs (Ver.27B and character generator) recently dumped from a M23F. Could you attach your dump of Ver.24B so that I can support that too?Off-topic, but I have a little news to share: a SORD M23 Emulator has been released. This emulator can read and run the M23 BASIC disk image from the Internet Archive without any problem. BIOS data is required to run this program, but it works without FONT data.
My emulation is currently failing to read the BASIC disk image, reads a few tracks into RAM then gets stuck, likely interrupt issues according to your blog. My CTC clocks match your source so am struggling to understand what I've missed, any clues?