Currently, the limits on accessing the VRAM in the V99x8’s MSX1 modes are not emulated.
As I understand it this information is available from the openMSX team’s V9938 measurements, just not interpreted and implemented yet.
<wouterv> kanima, grauw: (very preliminary results) i started looking at some (old) logic-analyzer measurements we took on a v9938, more specifically for the msx1 modes (i mostly ignores those for my VDP VRAM timing article) ..
<wouterv> .. it seems that on v9938 both text1 and text2 follow exactly the same vram access pattern
<wouterv> so text1 is doing the same number of vram reads as text2, but more than half of them are dummy reads
<wouterv> similarly all character modes use the exact same access pattern. So even though multi-color mode (screen 3) doesn't really need a color table, it still fetches dummy data at those moments in time
Implemented in commit 7f52e8691b340a1f85de5805113cfd5f33ee0772 by Wouter. Thanks!
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