timing interrupt routine

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zx81user
Posts: 54
Joined: Mon Mar 25, 2013 3:14 am

Re: timing interrupt routine

Post by zx81user »

dr beep wrote:This should work!

Code: Select all

in your mainprogram

       LD   IX,mycode

mycode CALL #281	; the normal IX routine
       
myprog NOP

end    CALL #292
       CALL #220
       LD   IX,mycode
       JP   #2A4

I don't follow this reasoning completely.
Since the interrupt routine is called twice, I need to know in my routine if I need to call address #281 or #28F. In your example it will always call #281, right? I would expect some examination of the AF register, or FRAMES to determine which one of the 2 addresses to choose.
Or are you handling the complete screen, basically omitting the second interrupt?
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