Allison J Parent wrote:
>
> <One of the smallest multitasking systems I've seen was the I/O processor
> <on the PERQ 2's. It was a Z80 with 4K ROM and 16K RAM, but said ROM
> <contained essentially a cooperatively multitasking kernel. Some tasks
> <were in ROM, others were loaded into RAM. OK, so the user never realised
> <what was going on, but that doesn't alter the fact that it was there :-)
>
> The smallest I've seen run on 8080 and fits in some 100 or so bytes. It
> was published in Kilobaud April 1978 page 102 and yes it was real.
>
> To multitask on most anything all you need is an interrupt and save the
> context of the current task and start some new task... the order, where
> the tasks are and memory allocation can be somewhat tricky but, for
> small tasks its pretty trivial. I've done it in 8048 MCUs where the
> resources were 64byts of ram and 1k of rom and the tasks were keyscan,
> display, serial IO and code conversion. The timer provided the
> interrupt.
Change of topic -- Allison, you're the first I've seen mention owning
Kilobaud Mag of that era, I _really, really_ want copies of two
articles from the magazine. One is from (i think) about August 1978,
"Is there Intelligent Life in Your Computer Room" [humorous], the
other is (i think) from about November 1979 "Amazing Mazes" [code, in
BASIC]. If you've got them, I'll accept photocopies in almost any
condition or I'll stop off and borrow them for ten minutes and get them
copied since that's the best reason I can think of to up to go to New
England and expose myself to my 25th high school reunion in Laconia NH
in July.
(Well, if I needed another reason, my hairline is still where it was
back when I was 18, and I suspect that some of the former jocks have
toupees that can be casually pocketed while I'm shaking their hands).
--
Ward Griffiths
They say that politics makes strange bedfellows.
Of course, the main reason they cuddle up is to screw somebody else.
Michael Flynn, _Rogue Star_
Received on Wed Jun 10 1998 - 22:50:00 BST