Re: LZ: INTZS


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Re: LZ: INTZS



> Ed Plese, Jr. wrote:
> > 
> > I have yet another question.  In interrupt mode 1, where does the CPU
> > jump too?  The code for the interrupt demo and grayscale routines
> > both look as though it jumps to the memory location pointed to by the
> > bytes in the graph mem.  Can someone explain this?
> > 
> > Thanks
> > 
> > -Ed
> 
> Interrupt mode 1 makes a RST 38h. That's way you see a jp $38 at the
> end of the grayscale routine. But I don't have a clue what IM 0 does.
> Anyone who knows?
> it get's a byte off teh data bus and executes it... this is left 
over from the 8080, in which peripherals put out RST instructions on 
teh data bus...


Rob Taylor MAIL - mailto:rtaylor@ticalc.org 
           WEB  - http://www.u-net.com/~rtaylor/    


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