On Thu, 1 Jan 2009, Eric Rucker wrote:
I've been thinking about stuff, and got to thinking... it'd be
interesting if there were a semi-modern, multitasking, graphical OS
for the IIGS - not necessarily backwards compatible with GS/OS. (The
semi-modern bit means... The Manager on GS/OS does NOT qualify. ;))
Anyway, I'm thinking that starting from scratch with the OS might just
be the best bet - unlike GNO/ME, which uses GS/OS for a lot of stuff.
That doesn't mean that I'd be shunning all of the built-in IIGS stuff
- the Toolbox would come in handy for the GUI. (FWIW, I think I know
how I'd handle the toolbox in a multitasking environment - simply
create a "virtual toolbox" that apps for this OS would make calls to,
and then pass those calls onto the real toolbox. As far as the real
toolbox is concerned, it's just one app with a bunch of windows, that
wants to change its menus. A lot. ;))
But, I suspect a modern multitasking kernel for all of this would be
more efficient. I know, there's no MMU. That never stopped Minix or
ELKS...
There was multitasking on 8bit computers. I seem to recall Microware
had it on the 6800, and there might have even been an article about
a multitasking monitor or kernel in Kilobaud (I can sort of picture it).
Then of course, Microware did come out with OS-9 for the 6809, which
admittedly is fancier than the 6502.
The concept of multitasking was fairly easy, there was a book about the
68000 that had a monitor or kernel that multitasked. Dr. Dobbs probably
ran some stuff on that too.
It just really depends on what you want. In the old days, the operating
systems were pretty simple, indeed some times it was just a matter of
running two programs that stood alone, the multitasking just being a
switch between the two. An obvious example was a print spooler, sharing
the CPU to send the characters to the printer in the background. Those
were described back then too.
Even Unix was simple to begin with, the PDP-11 that it was originally
run on did not have memory management. Of course, Unix was far more
than the kernel, it was the utilities and the applications that made
it useful, not so much the kernel.
Minix of course was designed to teach about operating systems, so one
might more properly be thinking about Minix in what it can teach about
the concepts, rather than a source to
You really have to decide what you are trying to do. Do some background
tasking, or a full blown OS? A completely new system that runs on
the 65816 (or even 6502?), or something that does multitasking but
allows existing programs to run on top of it? That last is likely
the most useful, since then you have things to actually do with
this OS, but is also likely the hardest since one has existing
specifications to meet.
Michael
Speaking of Minix, I'm almost wondering if some heavily-modified Minix
derived kernel would do the trick. The stock Minix memory manager can
only handle 64k of code and 64k of data per application on a 16-bit
CPU (I think that's a word-length restriction,) but maybe that could
be fixed? Binary compatibility with Minix would be unnecessary, so...
And, IIRC, it has installable file systems, and stuff like that, which
would work nicely in the IIGS ecosystem.
But, Minix is just an idea, and isn't necessarily the best one. It's
just something to think about.
Is anyone interested in such an OS? Either using it, developing it, or
developing for it?