Re: Multi-Tasking on Apple IIgs?

[et472@FreeNet.Carleton.CA (Michael Black)]

"Michael J. Mahon" (mjmahon@aol.com) writes:
> The Wizard of Oz wrote:
>> On Thu, 10 Mar 2005 18:57:51 +0000, Bryan Parkoff wrote:
>> 
>> 
>>>    Is there a way to write assembly language that can run two applications 
>>>at same time as multi-tasking?  It has to run first application and then 
>>>switch to run second application at the same time.  It may be the Program 
>>>Counter register that it can be modified.  I don't know how like Intel did.
>>>
>>>Bryan Parkoff
>> 
>> 
>> 	I was going to ignore this thread until I thought about the possibility
>> of co-processor cards. If a co-processor card could be active the same
>> time as the GS processor then you could get true multi-tasking as opposed
>> to the time slice mechanism everyone else is suggesting.
> 
> And, again, the software conventions assumed by most coprocessor cards
> and the hardware assumptions for sharing memory (like nearly stopping
> the main processor) make it very unlikely for any general multi-
> processor scheme to be implemented--unless you do it all yourself,
> that is.
> 
The cheap way to multitask is to get more than one computer.  Sort
of doable back then, if you were doing serious enough work that 
could warrant the price tag.  More doable as the hardware became cheap.
Have two separate computers next to each other (or three or four if
you've got the room) and roll your chair between them.  Remember how
much time printing took back then, and if you had a spare computer to do
it you could be doing other computing things at the same time.

Rather than general solutions, there were sometimes fixed solutions
for shifting the load elsewhere.  A hardware print spooler, for instance,
meant that one could "print" something in no time, and the spooler
would then take care of the actual printing, allowing you get get
back to work.  I have a standalone spooler, I've never used it,
and it has all of 64K of memory, which would have been wonderful when
it was new and expensive.  But my laser printer has something like
16megs in it (and I think I could put more in there if I actually
needed it), and of course any computer nowadays has software spooling.

   Michael