12/27/2022 0 Comments Tekken advance spritesThat rewrites valid data in the EEPROM, at least for the earlier versions. This was already noted in the driver comments.īasically through key combinations (not officially documented, I imagine) it's possible to trigger a Write ID message Otherwise only few sets would have worked with the available EEPROM dumps. The 6 th step was investigating if it was possible to generate valid EEPROM data for all the software revisions. The slightly more tedious work was to attain correct colors as they're handled differently than in the bootleg: (all registers are set to 0) and resorts to a separate tilemap chip (the ST-0009, probably). In the end I found the ST-0020 is capable of handling 4 tilemaps, yet curiously the Gundam game does not use any of them a possibility quickly debunked as its video registers were untouched. They came from the ST-0016 which has sprites as well. So the 4 th step was to have a second look at the ST-0020 as it probably could produce some scrolling layers. Sprites + tilemap arrangement (or does it? I have to revisit that assumption), provides an handy reference of what should be going on here the bootleg, which runs on a more traditional This got me in-game but there actually were no backgrounds. I only had to adapt the handlers for a 32-bit bus (jclub2 uses a 68EC020). (latches and a status register) and its rom banking from another driver. Easy, as I could lift the communication with the sound CPU Past the Broken ID message lied.ģ rd step was thus hooking up the ST-0016. I tackled the ST-0020 + ST-0016 hardware first, since both the video and sound chip are already emulated. The program jumps to the updated code at boot when it finds the magic "JC2X" string at offset 0x3fc in their ROM. The board has an empty socket near the main program for this Versions ending with an X were supplied by Seta as smaller upgrade ROMs. It turns out we have roms for 10 (!) versions of the game, including a prototype (Release Candidate): To the software version so an earlier revision won't be able to boot with an EEPROM from a newer game version. Thus the 2 nd step was to split the existing sets properly, by hardware and software revisions. So the 1 st thing I did was to add support for this variant with the help of the datasheet, which fixed the EEPROM check For the older PCB, though, I found there was another problem,Ī subtle difference between the Seiko S29290 EEPROM chip used and a standard 93C46-compatible serial EEPROM. Most will not boot since the dumped ID is from a later game version. Now, we do have dumps of the EEPROMs from both PCB revisions from two specific game versions. The latter chip in fact holds programmable non-volatile data such as the game configuration.īut, as a form of protection, it must also contain an ID string supported by the software for it to boot. What those messages actually mean though,īy looking at the code, is that the software is not happy with the data found in the EEPROM. (jclub2o, jclub2ob) and with Broken Configuration on the new hardware (jclub2). Up to now you were greeted with an ID Error message when running either of the two existing sets on the older hardware the horses are pre-rendered at each size in the graphics, as Dark Horse shows. This game not so much, zooming isn't actually used i.e. The ST-0020/ST-0032 provides some nice zooming sprites, which the Gundam game above uses extensively (see gdfs in ssv.cpp). Thus doing without the ST-0016 and reducing the cost. The newer PCB instead used an ST-0032 chip, an updated version of the ST-0020 that includes sound capabilities, Older PCB: ST-0020 (under the heatsink) + ST-0016
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |