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@ping: I think they're somewhere on ESE's site. I doubt they're 100% up to date, but I remember seeing at least some V9938 code there.

Can you give me the URL?

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Quote: @ping: I think they're somewhere on ESE's site. I doubt they're 100% up to date, but I remember seeing at least some V9938 code there. Can you give me the URL?

y00 lazy git!

oh, and here is the VDP code...

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oh, and here is the VDP code...

very thx!

And on www.hat.hi-ho.ne.jp/tujikawa/esepld/ you can find some pld code concerning MSX.
I hope this will useful too.

I am trying to port this code from ohanaka on the digilient board with a spartan 3S.
I have a problem because there is one SRAM on this board which access have to be shared
between cpu and VDP. I have some solutions but it always end up with strange video signal.
Though i can see the msx basic1 boots on the RTL I have . I am currently preparing my wedding
for the very next weeks so I will see this problem later on august.
I have Xess and digilent board with spartan 3S1000 , the vdp+z80+rom+psg+ppi fit in 40% of the core.
I recommend the Z80 core from fpga arcade, the one from opencores is buged.

which? the one z80 that can runs up to 250mhz?

is severals, which you means?

At first I had a version with VDP+Z80 and minimal rom of 2K all inside the fpga.
Actually a Z80 alone can run fast but with external sram this slows down.
For instance : there is a 10ns access sram on digilent board + I budget 10ns for pad/pcb delay => 20ns period = 50MHz Freq.
Moreover If this access is shared between VDP/CPU , the speed is around 50/2 = 25MHz.
In fact I use the same 21MHz clock for VDP and Z80.

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Moreover If this access is shared between VDP/CPU , the speed is around 50/2 = 25MHz. In fact I use the same 21MHz clock for VDP and Z80.

Do you mean that you have somewhat that emulates z80+vdp ready ? At stage of test?

Btw, you can download the complete source code of the CPC TREX core here:

http://www.symbos.de/download/cpctrex-quartussnapshot10.zip

The very interesting thing here could be the completely new Z80 implementation: It needs only half of the LEs of the OpenCore T80, is very fast and seems to be completely bug free. The only disadvantage is, that it's not commented.

PingPong : take a look at www.hat.hi-ho.ne.jp/tujikawa/esepld/ there are links to vhdl source of VDP

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PingPong : take a look at www.hat.hi-ho.ne.jp/tujikawa/esepld/ there are links to vhdl source of VDP

Thx, I already know this. I was thinking you had your own implementation...


Do you think it is possible to have a "turbo" VDP implementation?

(More quicker commands, more than 8 sprite per horiz. scan line? for example?)

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Do you think it is possible to have a "turbo" VDP implementation? (More quicker commands, more than 8 sprite per horiz. scan line? for example?)

This one could give you a start

dudes....

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Do you think it is possible to have a "turbo" VDP implementation? (More quicker commands, more than 8 sprite per horiz. scan line? for example?)

That should be fairly easy, a matter of a few values I suppose. This would of course decrease backwards compatibility unless it could be made 'switchable' which would be a bit more difficult I guess.