Hey, Obtained a slightly broken AT Games, handheld... With the 20 built in generic list of a few gems, with the added extra of an SD card slot...
Thinking this is exactly the same as everything other handheld, I assume its the same pinout to add the cartridge slot... also, would it not be cheaper to recreate 68000 PU rather than an entirely cheaper and more offcut emulation core which the sound and lack of VDP remove the support.. Plus i miss carrying around my nomad.. That sadly is dying!!, LCD keeps flashing every so offten then needs turning off for a few hour...
How is everyone doing? Just lost pretty much 6 years of my life's data from mega hard drive corruption,
Looking for a project to keep me occupied till i can stomach whats just happened....
Anyway thanks!
Blaze/ATGames Ultimate Megadrive Handheld... GOAC Cart mod
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Blaze/ATGames Ultimate Megadrive Handheld... GOAC Cart mod
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I'm not sure if it's an emulator or a genesis on a chip. But, It appears to be similar in concept to the VT 03 NES system on a chip. It supports the normal VDP registers and seems to offer additional modes.slobu wrote:Isn't the AT Games stuff emulation on a 32 bit chip of some sort? "Firecore" or whatever?
I downloaded the roms from the AtGames site (http://www.mugaatgames.net/Free_Trial.html) and they load up and output music in Fusion and MESS. They show a flash, but then it's a blank screen.
I want to look through the VDP register settings, and see if they're using some illegal bit combinations to allow for an 8 bit graphics pattern, and a larger palette. Sparkling Truffle has too many colors for a normal Genesis display.
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Those are emulator clones, not GOAC. I did a quick disassembly of one those games... it looks like it assumes things like the rom being writable - look at this
The code at 3E2 is a 32bx32b signed multiply. See how it assumes $378 is writable? Who knows what else they assume about the emulation.
Also, for these roms to even start on a TMSS Genesis, you'd need to put 'SEGA' at offset $100. It DOES use the standard startup, including setting the TMSS register to 'SEGA'.
Code: Select all
lbW000378 dw $D94B
00037A dw $A852
00037C MOVE.L (lbW000378,PC),D0
000380 TST.L D0
000382 BNE.W lbC000396
000386 MOVEQ #$10,D1
000388 LSL.L D1,D0
00038A OR.L ($FF8944),D0
000390 MOVE.L D0,($378)
lbC000396 PUSH #$BB40E62D
00039C PUSH (lbW000378,PC)
0003A0 BSR.W lbC0003E2
0003A4 ADDQ.W #8,SP
0003A6 ADDQ.L #1,D0
0003A8 MOVE.L D0,($378)
0003AE LSR.L #8,D0
0003B0 ANDI.L #$FFFFFF,D0
0003B6 RTS
Also, for these roms to even start on a TMSS Genesis, you'd need to put 'SEGA' at offset $100. It DOES use the standard startup, including setting the TMSS register to 'SEGA'.