TRH9000: an Open Source video card based on the original GFX-9000 | By MSXALL
The V9990 was once pointed as the new VDP chip of choice that should have been released together with the MSX Turbo-R in 1991. Yet today, it is uncertain if it is actually true, but the fact the MSX Turbo-R was released with a VDP no other than the very same used in its predecessor, the V9958; and based on the fact the V9990 is not exactly retro-compatible with it, but in fact some sort of "complementary upscale" chip, the story makes a lot of sense. Stories apart, the point is: it is not possible to replace the V9958 by the V9990 and have a functional MSX as it is somewhat possible with the V9938 and V9958 (the VDPs of the MSX 2 and MSX 2+ respectively). The V9990 can surely operate as an additional power module for its predecessors and even other VDP's, but for it to be possible an entire video card circuit must be implemented to integrate the chip features to the equipment and allow a functional MSX machine to operate with it. The first successful cartridge that manage