STAGE TWO VBLANK
At location VVBLKI (546,547), we discussed the various stages of VBLANK and I promised a list of things that were done during stage two. This is that list.
The following hardware registers are updated with the values in their shadow registers (listed in the order they are updated):
|PCOLR0-3||COLPM0-3 (Colors are first adjusted for the|
|COLOR0-3||COLPF0-3 attract mode.)|
The following shadow registers are updated with the values in the corresponding hardware registers:
In addition to all this, the following timers are decremented, and the appropriate actions taken if they reach zero:
Note that the last two timers deal with the keyboard debounce and repeat, respectively, and are only decremented if necessary. CDTMV1 is taken care of in stage one.
Finally, the last thing stage two does is jump through VVBLKD (548,549).
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