Re: A86: Re: Timings
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Re: A86: Re: Timings
You also need to remember that your program doesn't get to use all 6 mil cycles
unless you disable interrupts - the 'software' interrupt runs approx. 174 times
per second (or so I've heard). The easiest way to count off a second,
therefore, is probably to install a user interrupt that counts down from 174:
seconds:
.db 0
.org _user_int_ram
user_int:
push af
ld a,(counter)
dec a
jr nz,notyet
ld a,{seconds)
inc a
ld (seconds),a
ld a,174
notyet:
ld (counter),a
pop af
ret
counter:
.db 174
.end
David Phillips wrote:
> The Z80 in the 86 runs at 6Mhz, or 6,000,000 clock cycles per second. An
> instruction is measured in t-states, or time states. A 4 t-state
> instruction, such as NOP, would execute 1.5 million times in a second
> (though I have heard this is not exact, can anyone confirm?).
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