The SC/MP... it lives!
stanb at dial.pipex.com
Sun Mar 27 02:17:24 CST 2005
> I've got a few old SC/MP-II chips and I decided to try and do something with them.
> It appears that only 2 of the chips actually work, but I've just proto-typed a small
> system with 4K ROM, 4K RAM, an 8251 USART and an 8255 PPI. I got the
> comms going yesterday and the PPI is fine. Excellent old vintage stuff.
Excellent! I've a soft spot for the old SC/MP, and I still have my old
Science of Cambridge (Sinclair) Mk14, which still works. Before that
I had a home-brew system based on a board produced by a local firm here.
This was about 1976/7
> I forgot how cumbersome the SC/MP instruction set was, but it's fun trying
> code around its deficiencies. I've got a listing of the original KITBUG for
> SC/MP, but I'm going to expand on it to provide more functionality. I'll
> try and
> base the monitor off the old Intel 8080 SBC monitor.
The instruction set has an elegant simplicity :-)
It makes position independent code easy though, and I wrote an operating
system for the Mk14 that allowed me to load numbered programs from tape,
with auto-run if required, multiple resident programs (in 1K ram!), and
would recover the memory vacated by deleted programs. Good fun...
I did start to write an emulator, the basics of which I prototyped
and it works, but other projects got in the way. Not sure where the
code is now.
Stan Barr stanb at dial.pipex.com
The future was never like this!
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