The SC/MP is finally alive!

Allison ajp166 at
Tue Apr 5 12:47:33 CDT 2005

>Subject: Re: The SC/MP is finally alive!
>   From: Wai-Sun Chia <waisun.chia at>

>After having looked it up, the literature says that one of the unique
>feature of the SC/MP was/is the ability to share the system bus with
>other peers, therefore was designed for multiprocessing embedded

Yes.  I used one of the later 8073 (SC/MP-II in Nmos) running Nibble
Basic and used a second SC/MP-I (oldest pmos part) in an arrangement 
so the basic one did IO via the second using a shared bit of ram.
It was impressive then (1980).

>The site further acknowledged that this feature alone makes th SC/MP
>II one of the most advanced design of its time.

it was a little used but unique feature.  However, it was also over 
rated as it took trivial TTL logic to get the same functionality 
when using 8085 or Z80s in multiples.

>So anybody is planning to build a cluster of these babies? :-)

Not likely. As micros go it was slow and if that much cpu was 
needed to share/multiprocessor an application people move up to 
Z80 or 8088.

>p.s. do you have pics of your SC/MP system? I would love to have a
>look at them...

Yes, slides really.  I only just got a digital camera so I have to dig 
stuff out and take pics, someday.

[keeper of old compuers, SBCs, S100, DEC PDP-8, PDP-11 and VAX]

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