Since the analysis of BIOS of SORD M68MX was settled, I burned a handy monitor to ROM and ran it.
zBug is a monitor program for the "68k Single Board Computer" developed by Wichit Sirichote.
To this program, kanpapa added the ability to read S1 type S-record, and made various modifications, resulting in V1.0.1. The source code is on GitHub and is in the Easy68K assembler syntax.
In porting the SORD M68MX, I just modified the ACIA address. Originally, it was necessary to modify the address of the RAM stack, but it worked without modification.
A former SORD development staff member told me on Twitter that the RAM is simply placed from 0x0. So, it seems that there is no need to be too cautious if the program is only a monitor.
When I got my M68MX, it came with no keyboard or monitor, just the main unit. So far, I could only look at the curt boot screen, but now I can let the M68MX execute various commands.
In the truest sense of the word, I feel like I have acquired a SORD M68MX. I'm very impressed.
I'm going to write a program to control the floppy disks, and eventually, I'd like to boot the CP/M-68K.
zBug command list.
