d.4) The stupid line-216 feature to disable the lower priority sprites should never had existed. Not only this feature isn't useful on the MSX2, as it causes problems to the vertical scrolling games.
I fully agree. It is one of the most crappy and stupid VDP feature. even on TMS. worse on V9938. And an example of following some stupid design original ideas born on TMS
Vertical scrolling is best that on most other platforms, because it is circular, allowing lighter cpu load.
Horizontal scrolling is not on v9938
on TMS there is nothing.
Is it really true though that horizontal scrolling is necessarily not circular? I seem to remember on the SMS it kind of is, and in some old 8bit arcades it definitely is.
That said, I've always been amazed with some MSX1 games actually having a good smooth scrolling (even horizontal). Probably using cheap tricks, but nevertheless it looked good. And what was the name of that japanese MSX2 platformer that had good scrolling?
the problem with v9938 is that had to be compatible with crappy msx1 vdp.
sprites with limitations in colors are the perfect example of this.
Sega Master System's VDP was based on the TMS9918 (although not compatible), and that had proper sprites and scrolling.
Based?
in the sense it is compatible. the sms vdp is another beast, electronically and from the point of view of architecture.
SEGA revised heavily the SMS VDP, mode 4 and sprites are a clear example of this.
Like I said before, I'm not a hardware guy so I wouldn't know about the inner architecture of the SMS VDP. It being compatible with the TMS9918, I sort of saw it as like a TMS9918 with SMS's display mode bolted on top, but I'm sure that's probably just my overly simplified view
I sort of saw it as like a TMS9918 with SMS's display mode bolted on top, but I'm sure that's probably just my overly simplified view
Because that's exactly what it is. The point was keeping it 100% compatible with the older games SEGA had already released for the SG-1000 and SC-3000 products.