swapd0 Posted March 31, 2021 Share Posted March 31, 2021 (edited) I'm trying to copy the roar sample from the boot rom to ram and play it with u235se, but I get a weird sound. Maybe I can't access the Boot ROM because I got a Skunkboard inserted? The sample (11025Hz) is located at Boot ROM offset 0xc1b4 to 0x127f4. Edited March 31, 2021 by swapd0 Quote Link to comment Share on other sites More sharing options...
Zerosquare Posted April 1, 2021 Share Posted April 1, 2021 The boot ROM is 8-bit wide with 10 cycles access time. The Skunboard Flash memory is 16-bit wide with 5 cycles access time. The settings in MEMCON1 affect both, so if you want to read the boot ROM, you need to change the value of this register (from code running in RAM, of course, otherwise it'll crash) and restore it after you're done. Keep in mind that accessing the boot ROM will make your game incompatible with the BJL ROM. 1 Quote Link to comment Share on other sites More sharing options...
swapd0 Posted April 1, 2021 Author Share Posted April 1, 2021 (edited) Ok, now I read the data properly but it looks that there are sightly differences in the Boot ROM, because I get some glitches at the start, but if I cut the jagbios.rom from 0xc1b4 to 0x127f4 and play it in Audacity it works... Also I've dumped the values that I'm reading and they are part of the bitmap that is located before the sample. Edited April 1, 2021 by swapd0 Quote Link to comment Share on other sites More sharing options...
SCPCD Posted April 1, 2021 Share Posted April 1, 2021 Not all jaguar have the same bios. There is some different version depending of the revision/manufactured unit : you can't rely on an offset. 2 Quote Link to comment Share on other sites More sharing options...
swapd0 Posted April 1, 2021 Author Share Posted April 1, 2021 1 hour ago, SCPCD said: Not all jaguar have the same bios. There is some different version depending of the revision/manufactured unit : you can't rely on an offset. If you think about it, it's logical but I didn't realize. Quote Link to comment Share on other sites More sharing options...
DEATH Posted April 25, 2021 Share Posted April 25, 2021 As far as I can remember there is only 2 BIOS version. One for M models and one for K models. I seem to remember that one of these versions can work on the K and M models, while the other version can only work on one model. It seems to me that the subject had already been approached, maybe in another forum, maybe by myself... And the difference between the 2 BIOS was the initialization startup, of the video I believe. Quote Link to comment Share on other sites More sharing options...
Zerosquare Posted April 25, 2021 Share Posted April 25, 2021 Yes. The "M" ROM appears to work fine on both the K and M models, while the "K" ROM doesn't always boot correctly on M models. And the video init is indeed different (but I don't know if this is the only difference). Quote Link to comment Share on other sites More sharing options...
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