Question about vdp of msx2

By nikodr

Paladin (748)

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11-05-2011, 14:21

I have the following question :What is the maximum number of bytes a vdp9938 on msx2 can handle on a limited number of interrupts that is ?I am talking about a pal machine,is there a way to overcome that limit?Would it ever be possible for an msx2 machine to have dma transfers of data from vdp to cpu ?(and so be able to do other tasks or is this not available under msx ?)

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By PingPong

Prophet (4093)

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11-05-2011, 19:57

I have the following question :What is the maximum number of bytes a vdp9938 on msx2 can handle on a limited number of interrupts that is ?I am talking about a pal machine,is there a way to overcome that limit?Would it ever be possible for an msx2 machine to have dma transfers of data from vdp to cpu ?(and so be able to do other tasks or is this not available under msx ?)

about bytes manageable it depends on various situations.
about a true DMA (meaning the ability to move data between ram and vram without cpu attention, unfortunately there is no way on a standard msx2 vdp). If you are meaning the ability to move bytes regions around vram, instead, the answer is yes. the vdp can move region of vram data without cpu usage, concurrently and in parallel with the cpu work. But only between vram and vram. you can see an example of such thing using the LINE or COPY command in basic.

By Metalion

Paragon (1622)

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12-05-2011, 13:58