Re: Re[2]: A86: Dead list?
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Re: Re[2]: A86: Dead list?
You're close, it's port 0. Port 2 is contrast.
Mode 0 sucks? I don't know why you say that, but it isn't used on the
calculator. In mode 0, instructions place an instruction on the data bus to
be executed. If you set mode 0, random instructions would be executed, no
doubt causing the calc to crash.
Mode 1 isn't significantly slower, especially if you pop the return address
off the stack and reti to the program. The built in handler has a little
overhead, like calculating the checksum, but not enough to cause problems.
It has the advantage that it takes no extra memory, because there is 200
bytes allocated for it. If you call $01a1 (patched) during the interrupt,
then the difference between mode 1 and 2 becomes quite trivial.
Mode 2 is the fastest, but requires at least 300-400 bytes. If you
absolutely need the fastest interrupts, go with mode 2. But for other
situations, mode 1 works the best. Despite what the 86 Central grayscale
tutorial says, interrupt speed has _nothing_ to do with grayscale quality.
That's all in the mixing ratio. 1:2 will achieve flicker free grayscale
(flourescent lighting seems to make flicker noticable), no matter how slow
the interrupts (unless you start missing them...).
> No, you flip bit planes.
> aka, you change the area of ram use to display stuff.
> You'll have to write to port 2 I think (look at the help file) and set up
an
> interrupt.
> Mode 0 sucks, mode 1 is slower but easy to set up, but I like mode 2
because
> it's fast.
> Look in a tutorial or something.
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