Soft-HIRES Issue

If you want to ask questions about how the machine works, peculiar details, the differences between models, here it is !
How to program the oric hardware (VIA, FDC, ...) is also welcome.
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Twilighte
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Soft-HIRES Issue

Post by Twilighte »

As part of the current project, i must use my own set of routines outside the ROM. To this end i have written a routine to place the oric from text into HIRES mode.
The process is fairly straightforward, but with strange potential results.

Whats weird is that technically the generation of Soft-HIRES may not
always be reliable without a 20K cycle delay between setting and
clearing.

I write Code 28 to $BFDF to tell hardware to flick to full HIRES.
I then clear memory from $A000 to $BF3F with 64.
Finally i overwrite BFDF with the last 3 lines of text.

Surely if the raster is currently top of screen it may not reach BFDF
before i erase it again?
Seems ok in Euphoric though :P

Am i missing something obvious?