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BGPierce / VCC

Tandy Color Computer 3 Emulator
GNU General Public License v3.0
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32KB cartridge images - format? #7

Open tcdev42 opened 8 years ago

tcdev42 commented 8 years ago

Seems there is an incompatibility between Vcc and MAME/MESS for 32KB ROM images.

MAME/MESS want a naturally-ordered ($8000-$FFFF) 32KB block whereas Vcc requires that the top and bottom 16KB blocks are switched ($C000-$FFFF,$8000-$BFFF).

Whilst archives on the net tend to be in the swapped format (Vcc) and therefore incompatible with MAME/MESS, it's worth noting that this swapped format is also unsuitable for burning to FLASH/EPROM.

I would argue that the naturally-ordered format is easier to produce for developers, compatible with MAME/MESS and FLASH/EPROM burners. Should we also change Vcc to use this format?

BGPierce commented 8 years ago

Mark, I never noticed that myself. In Joes original code, the ROMs were built in, so this has been done during conversion. In fact, I thought the same roms were being used as in Mess/Mame.

Bill Pierce "Charlie stole the handle, and the train it won't stop going, no way to slow down!" - Ian Anderson - Jethro Tull

tcdev42 commented 8 years ago

Apologies Bill, I wasn't clear enough in my description.

I'm talking about cartridge ROMs, not ECB/DECB internal ROMs!

Luis46coco commented 7 years ago

In the program I can not see that, just load the whole block and activate it I will review more

BGPierce commented 4 years ago

Since there's actually been activity in the VCC development lately, I've been going through this list and seeing what can actually be fixed in the next revision.

My question would be, in what format is a "real" coco cart stored? VCC style or mame style? How many hundereds of carts would this break if this is changed?