This blog entry is the best info I've found:
https://newastrocity.wordpress.com/2013/07/21/cave-conversions/
it lists which games can be used as donors but it's unclear if you can use MAME ROMs or if the ROMs need to be patched to bypass security.
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LATEST UPDATE: 2019-15-01
Since this thread has become so huge I've created a list of every IGS PCB Number I can find and if a successful conversion has been documented on it....
PCBs marked with:
* are suitable donor PCBs with successful documented conversions
+ are thought to be potential donors but have no documented conversions yet
- are thought to not be suitable for conversion
~IGS PCB NO-0133-2 (Main board) [the main board of the mobo]
-IGS PCB NO-0134-1 (PRG) - Oriental Legend
-IGS PCB NO-0135 (GFX) - Dragon World II, Oriental Legend, Oriental Legend Super
~IGS PCB NO-0136 (Riser) [cart port on the mobo]
-IGS PCB NO-0162 (PRG) - Dragon World II
+IGS PCB NO-0179 (PRG) - Killing Blade +Espgaluda +Ketsui
*IGS PCB NO-0179-2 (PRG) - Killing Blade *Espgaluda +Ketsui
Conversion 1 Conversion 2
*IGS PCB NO-0178 (GFX) - Killing Blade, Dragon World 3, Dragon World 3 EX *Espgaluda +Ketsui
Conversion 1
-IGS PCB NO-0189 (PRG) - Dragon World 3
-IGS PCB NO-0189-1 (PRG) - Dragon World 3 EX
-IGS PCB NO-0191-1 (PRG) - Oriental Legend Super
+IGS PCB NO-0212-1 (PRG) - Knights of Valour +DDP DOJ
*
IGS PCB NO-0213 (GFX) - Knights of Valour Plus *DDP DOJ
conversion 1
+IGS PCB NO-0213T (GFX) - Knights of Valour +DDP DOJ
-IGS PCB NO-0220 (PRG) - Photo Y2K
-IGS PCB NO-0221 (GFX) - Photo Y2K
+IGS PCB NO-0222 (PRG) - Knights of Valour, Knights of Valour Plus +DDP DOJ
*
IGS PCB NO-0222-1 (PRG) -Knights of Valour Plus *DDP DOJ
conversion 1
-IGS PCB NO-T0236 (PRG) - Puzzle Star
-IGS PCB NO-T0237 (GFX) - Puzzle Star
*
IGS PCB NO-0256-1 (GFX) - Knights of Valour Super Heroes *DDP DOJ
conversion 1 conversion 2
+IGS PCB NO-0257 (PGR) - Knights of Valour Super Heroes +DDP DOJ
*
IGS PCB No-0257-1 (PRG) - Knights of Valour Super Heroes *DDP DOJ
conversion 1 conversion 2
-IGS PCB NO-0258 (GFX) - Puzzli 2
-IGS PCB NO-0259 (PRG) - Puzzli 2
+IGS PCB-0292-00 (GFX) - Martial Masters +Espgaluida +Ketsui
+IGS PCB-0293-01 (PRG) - Martial Masters +Espgaluida +Ketsui
-IGS PCB-0313-00T (PRG) - Photo Y2K2
-IGS PCB-0314-00 (GFX) - Photo Y2K2
+IGS PCB-0333-00 (PRG) - Knights of Valour 2 +Espgaluda +Ketsui
*IGS PCB-0333-01-FT (PRG) - Knights of Valour 2 +Espgaluda +Ketsui
Conversion 1
+IGS PCB-0333-02-FI (PRG) - Knights of Valour 2 +Espgaluda +Ketsui
*
IGS PCB-0333-03-FI (PRG) - Knights of Valour 2 *Ketsui *Espgaluda
Conversion 1 Conversion 2 Conversion 3 Conversion 4
+IGS PCB-0333-09-FI (PRG) - Knights of Valour 2 +Espgaluida +Ketsui
*
IGS PCB-0334-00 (GFX) - Knights of Valour 2 *Ketsui *Espgaluda
Conversion 1 Conversion 2 Conversion 3 Conversion 4
-IGS PCB-0349-01-FL (PRG) - Dragon World 2001
-IGS PCB-0350-00T-FL-A (GFX) - Dragon World 2001
+IGS PCB-0354-01-FN (PRG) - DoDonPachi 2 +Espgaluida +Ketsui
+IGS PCB-0355-00T-FN-A (GFX) - DoDonPachi 2 +Espgaluida +Ketsui
+IGS PCB-0387-02-FV (PRG) - Demon Front +Espgaluida +Ketsui
+IGS PCB-0390-00-FV-A (GFX) - Demon Front +Espgaluida +Ketsui
*
IGS PCB-0490-00-GZ (PRG) - Knights of Valour Super Heroes *DDP DOJ Conversion 1
(info) (pics)
*
IGS PCB-0568-00-GZ-B (GFX) - Knights of Valour Super Heroes *DDP DOJ Conversion 1
(info) (pics)
---------------------------
These are the ROM files to use:
Do Don Pachi Dai Ou Jou
-Program ROM (Black Label Only): ddpdojblkbl
-Program ROM (white Label Only): [unavailable]
-Program ROM (Dual Boot): [undumped]
-All other ROMs: ddp3
Espgaluda
-Program ROM: espgalbl
-All other ROMs: espgal
Ketsui
-Program ROM (Original Only): ketbl
-Program ROM (Arrange Only):
Any PGM Conversion info out there?
-Program ROM (Dual Boot):
Any PGM Conversion info out there?
-All other ROMs: ket
---------------------------
Other useful threads:
Ketsui Trap Arrange ROM:
Any PGM Conversion info out there?
Ketsui dual boot ROM:
Any PGM Conversion info out there?
Ketsui dual boot switch wiring:
Any PGM Conversion info out there?
Ketsui dual boot switch mounting:
Any PGM Conversion info out there?
non-board specific PAL Modification Instructions for Ketsui and Espgaluda
Any PGM Conversion info out there?
program ROM PCB mapping
Any PGM Conversion info out there?