At 11:02 AM 5/20/99 +0200, you wrote:
>However, one problemo...
>When I set the adjust while a VDP-command is executing, there appear some
>'noise'-pixels on the screen.
Are you sure it's related to the adjust? Simply executing copies to a
visible page will give noise, even if you don't tough the adjust. If you're
copying to a visible page, always make sure that you time the copy so that
the area copied is never the same as the area sent to the monitor at that
time.
For example, if you copy an area from line 16 to 32, start the copy on line
32 or later (but not too late). If you copy an area from line 128 to 144,
start the copy on line 144 or later.
What will probably work is to devide the screen into a top and bottom part
and put a line interrupt around line 128+NY, where NY is the size of the
block you copy (for example 16). Copies for the top part are started by the
line interrupt, copies for the bottom part are started on the VBLANK
interrupt.
By the way, if any of you ever wondered why the cursor in GraphSaurus
blinks when it moves in the top region of the screen... its copy command is
issued on the VBLANK interrupt and may not be finished when the scan
reaches the top of the screen!
>For example, during the screensplit I disable the screen, and at the end I
>enable it again. This however gave a white line at the lowest (second) line
>of the screensplit. I was able to solve this problem by making sure the
>screen was enabled during the H_BLANK-period...
What do you mean by "during the screensplit"? Do you mean "when the VDP is
loaded with the new settings after a line interrupt occurs" or "the time
the scanner takes to reach the next line interrupt point"?
Bye,
Maarten
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