Re: 6502 Multitasking OS announce

[ralph.mason@liffe.com (Ralph Mason)]

Michael Ellis <michael@anest4.anest.ufl.edu> wrote:

>holger@deep.hb.provi.de (Holger Bruns) wrote:

>>An operating system for the 6502 should have some of the properties of CPM. 
>>Parameters could be passed into registers and some zeropage locations. 

>   The way to get around this is to pass all parameters on the stack, and use separate
>   stacks for the separate tasks.


All well & good BUT the 6502 does not have a relocatable stack pointer
so your kinda left with a bit of a problem when it commes to
multitasking, ie you cant give each process it's own stack without
copying the whole stack ( maybe just to the current sp value? )during
each context switch. 

-Ralph Mason