BCC: Rod - see Sc/MP alarm dialler comment. / Harvey :-)

>
http://files.righto.com/calculator/sinclair_scientific_simulator.html

>
The code surely doesn't translate directly into PIC assembly, but quite
> impressive.

In 'the early days' a friend used a NatSemi SC/MP with 256 bytes of fusible
link PROM (or was it the large 512 byte version?) to control a basketball
scoring system. This ran a main timer, timeout timer multidigit 7 segment
score displays in 2 locations and more. It's easy to forget how powerful a
few macjine language instructions can be.

The SC/MP had 16 internal 8 bit registers (AFAIR) and one company here
implemented an alarm dialer with no external RAM and the 16 registers as
the sole RAM in the system. After all, RAM was EXPENSIVE. A friend
subsequently was given the job of extending the system's capabilities, and
the lack of RAM proved a major headache.

I made an 8 bit reel-to-reel mag tape reader with a 6802. RAM was not a
problem - I may even have had about 8 kB, but processing speed (at 4 Mhz
clock) was. Fast enough only by pushing data to the stack in a tight loop.
I can't remember how it "delooped" -- may have used an interupt timer once
block read started. Worked well.


          Russell
--=20
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