Here's the continuation of this newspost!

VDU is an MSX "videocard" made out of 4x 9958 chips, thus 4 multilayer scrolls of high-color screens, 4x sprites etc. etc.

send me a vdu (for free) and i'll continue the debate :-)

well if it could be made on large quantities (example like manuel pazos's megaflash or sunrise cf adapter of v9990 cards) then it should be ok,otherwise it is just an interesting experiment for me.

Well, it can be made. I recently found a vendor with several v9990 - they probably should have some v9958 too.

The rest, as far as I know are implemented in FPGA, so it shouldnt be hard to make. Problem is the cost, besides the FPGA board, 3 v9958 wouldnt be something very cheap...

Oazem just made it "for the fun", but I bet if enough people show interest on this, he would make them... for now he is still thinking on what to do to make it even better (like adding more memory for at least one vdp, and/or making vdp access faster)

Another thing I just thought, this could be used to improve the EVA player -- since it uses the VRAM as a buffer, and with VDU we have 4x 128kb...

SymbOS maybe could benefit from it... imagine a wallpaper on SCR12 not interfering with anything else in the OS!

Hmmm... not even re-programming needed, just load a SCR12 image on VDP1, set VDP0 to be written to, and put a wallpaper on SymbOS with color 0,0,0 all over... and it's done

But ehm, if you're combining VDP's anyway, why not combine V9958 with V9990? That's also lots of power. In principle, the V9990 can be superimposed with the V9958.

Oazem is thinking about it... but first he has to get a V9990 to start experimenting

@Slotman: *EDIT* Cool chip search page, didn't know it before. I am interested in that, too.
In general wouldn't it be possible to build the 9958 or 9990 in current not too expensive FPGA chips?

Okay, sounds cool but...

What will the price be? Don't need exact prices (yet), but are we talking 100 or 300 euro's for example?

http://v99.isocomponents.com/part/V9958

IMHO the price for bulks of 8-10chips should be c.a. 16$/chip

I don't think relying on an FPGA would be good for the price. Maybe a small CPLD for some control logic or something. But even for those there are probably cheaper solutions.

hmm..implementing this in the OCM should not be that hard I gues...If enough gates are available on the FPGA. :-)

OCM couldnt even emulate one MSX2+ VDP, how do you expect it to do 4 of them?!?

What makes you so sure it can't emulate a v9958?

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OCM couldnt even emulate one MSX2+ VDP, how do you expect it to do 4 of them?!?

You're right, I forgot it has only V9938 implementation. What I ment was, that is should be a small step if the vdp is available in VHDL.

hmm..now I think about it, my expectation was some time ago that we would see regular upgrades for OCM.

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hmm..now I think about it, my expectation was some time ago that we would see regular upgrades for OCM.

*Cough!*Which OCM?*Cough!*