First up, the speed test. This displays a counter of the number of times a section of code is done, and the section of code is a pretty random cross section of SC/MP instructions , just enough thought to avoid crashes.
The purpose of this is to confirm that the replica can keep up with the software emulator, which it can.
Second up, a basic hardware test. This functions a bit like a teletype – whatever is typed in is displayed. At the same time, the lower three bits are sent to the sound system (system, seriously ?) to play the appropriate note.
This tests most of the hardware works as it should.
The exception is the cassette tape – as this is basically banging data out via SIO then I might code it, but there’s no real point in implementing it physically.
These two source files, plus the monitor (for the basic board, with 128 bytes of RAM and the video card, operated by the buttons a la Altair are in the software/miscellany directory.
These are assembled using Alfred Arnold's exceptional cross assembler AS, which as far as I know is the only SC/MP assembler except for my bodged TASM file of ten or more years ago.
I think the most up to date one is required as I have sent a couple of bug fixes in in the past.