Re: Multithreading OS for the C64

[csbruce@ccnga.uwaterloo.ca (Craig Bruce)]

In article <Dtvnp8.9p3@inter.NL.net>,
Maarten Ruigrok <M.Ruigrok@inter.nl.net> wrote:

>fs1@aixterm2.urz.uni-heidelberg.de (Andre Fachat) wrote:
>> - preemptive multitasking/multithreading
>how did you make it pre-emptive when the 6502 processor itself has no way to
>check for boundaries or anything (so called trap errors coming from the
>processor itself (in pc systems btw)). In what way can the operating system
>take back and control software running under it?. Maybe someone from 
>microsoft could implement it in their own products ;-).

Um, Timer Interrupts (IRQ).  They have been around for a long time.  I
personally have implemented them to implement multitasking in my VIC-20
and in my course-project Real-Time 486 multitasking OS.  It's not that
hard.  PC-industry OS developers just don't know what they're doing. :-)

Keep on Hackin'!

-Craig Bruce
csbruce@ccnga.uwaterloo.ca
"Never underestimate the power of a simple tool."

C=256,64K-VDC,REU,RL16,HD200,FD4000,SL,USR28.8,C=128,1581,1571,C=64C,1541,VIC20