Scrolling text in 80 column text mode

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Van hit9918

Prophet (2911)

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15-09-2016, 15:14

mhm 9600 is radical, is like asking 960 scrolls per second. asking some trick.
dont clear the line but go on printing. print with the cpu.
and then when the cursor leaves this line, at that point remember what rest is to be cleared and tell that the command engine.
and when that business doesnt finish then some old garbage is left.
but no garbage in the new incoming things, not missing escape sequences etc.

Van hit9918

Prophet (2911)

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15-09-2016, 15:19

on the other hand text mode could do tricks.
"if the UART buffer gauge is high then dont scroll but continue printing in the bottom border of vram".
and when the gauge is low enough to have a scroll then the scroll jumps multiple lines.
maybe this could go above 9600.

Van hit9918

Prophet (2911)

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15-09-2016, 15:34

another idea: 1920 bytes per console is no problem, you got 128k vram Big smile
store it somewhere in vram and then have some snail thread update it to visible vram.

Van hit9918

Prophet (2911)

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15-09-2016, 15:48

mhm to really write vram in a thread of multitasking would ask new platform wide policy
"not only VDP register writes but whole vram copies would need to be shielded with disable interrupt".
this doesnt work.

what I just called "snail thread"
and the copy loop to get things from the UART buffer to vram buffer
would need to be interleaved in one main app.

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