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Note that the EPCS4 might be too small to store both the ROMs and the Cyclone-II image (haven't tried compressing a 2C20 .SOF).

I tried, it is 239kB at the moment. So it fits, but it leaves not very much room for extension. But on the board there is also a parallel flash. It shouldn't be too hard to put the roms in there.

I'd like to know what the other segments of the hex file are? I'm assuming there are some character ROMs in there somewhere? Kanji??? I'm wondering whether you can do away with half of the 256KB ROM under certain circumstances so it only takes up 1/4 of the EPCS4???

I'm not sure how much magic poking around the IPL ROM does during startup, but if there's not a lot to it then it would be almost trivial to load the ROMs from parallel flash - just a matter of twiddling mappers really and copying blocks of memory around.

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I'd like to know what the other segments of the hex file are? I'm assuming there are some character ROMs in there somewhere? Kanji??? I'm wondering whether you can do away with half of the 256KB ROM under certain circumstances so it only takes up 1/4 of the EPCS4???

offset size function
0x40000 64kB DOS2 (including modified MEGA-SCSI rom)
0x50000 32kB Main-rom
0x58000 16kB Sub-rom
0x5C000 16kB FM-PAC rom
0x60000 128kB Kanji rom

I wrote a little perl-script to extract the binaries from the .PLD file:
http://home.versatel.nl/timmarianne/pld2bin.zip

So if jou can live without the Kanji rom (I can), then only 128kB is required for the roms.

I made some pictures of my own clone:

http://home.versatel.nl/timmarianne/OcmClone1.jpg
http://home.versatel.nl/timmarianne/OcmClone2.jpg

Unfortunately I had to remove the YM2413 because my FPGA is not big enough, for the rest it is fully functional.

Nicely done!

Is your design public? I'd be interested in seeing your IPL ROM code to see what the bare minimum is to configure the core correctly.

I don't have an SD/MMC slot on my hardware, but given the number of pins required, and the fact that I have dozens of free pins, it would be trivial for me to wire one up - I should look at doing that so I can actually play some of these games...

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Nicely done! Is your design public? I'd be interested in seeing your IPL ROM code to see what the bare minimum is to configure the core correctly.

I think not much people are interested in the source code because it is for very specific hardware, so I won't put it on the internet, but I will send it to you by e-mail (if someone else is interrested, send me an e-mail). The bare minimum for the IPL ROM is just to set the pallete registers correctly. I in a real V9938 the pallette is set to default values after reset, in the OCM code it is set to all 0's -> black screen. I also used it to test the functionality step-by-step in the beginning, when the thing did not work. Because in my case the init-code is not in the gateware itself I was able to reprogram it without having to compile the whole FPGA, which speeds up development a lot.

Here we go: another OCM clone.

I'd like you, guys, to work together, you can advance faster then !

Any news about those projects??? I'm losing my hope in Bazix and the OCM...

Caro's project for Altera DE1 (sorry, the discussion is in Russian only) is fully functional from August, and misses only cartridge slots, which also can be connected to the devboard.

Here is the recent topic written by Caro about OCM on the English forum, so you can try to contact him there.

Great news, Cax! Thanx