According to the game code, this is not a bug :

Code:


	0E5D1: 8A 1E 28 05               mov         bl,byte ptr [528h]
	0E5D5: 3A 1E 34 05               cmp         bl,byte ptr [534h]
	0E5D9: 75 09                     jne         0E5E4h
	0E5DB: 80 FB 02                  cmp         bl,2h
	0E5DE: 76 0E                     jbe         0E5EEh
	0E5E0: B3 02                     mov         bl,2h
	0E5E2: EB 02                     jmp         0E5E6h
	0E5E4: 32 DB                     xor         bl,bl
	0E5E6: 88 1E 28 05               mov         byte ptr [528h],bl
	0E5EA: 88 1E 34 05               mov         byte ptr [534h],bl
	0E5EE: A0 29 05                  mov         al,[529h]



This means that if you have 2 credits or less in NVRAM, nothing is changed when you launch or reset the game; and if you have more than 2 credits, this number of credits will be changed to 2 ...

Now the question is why there are more than 2 credits the first time you launch the game ... This is because the NVRAM handler defaults all values to 0xff when the .nv file doesn't exist :

Code:


static MACHINE_DRIVER_START( gottlieb )
	...
	MDRV_NVRAM_HANDLER(generic_1fill)
	...
MACHINE_DRIVER_END



Can this be told a bug ? I don't have the reply here ...


Note that the behaviour is the same with the clone 'mplanuk' (even if the addresses are slightly different) :

Code:


	0E5D1: 8A 1E 28 05               mov         bl,byte ptr [528h]
	0E5D5: 3A 1E 3E 05               cmp         bl,byte ptr [53Eh]
	0E5D9: 75 09                     jne         0E5E4h
	0E5DB: 80 FB 02                  cmp         bl,2h
	0E5DE: 76 0E                     jbe         0E5EEh
	0E5E0: B3 02                     mov         bl,2h
	0E5E2: EB 02                     jmp         0E5E6h
	0E5E4: 32 DB                     xor         bl,bl
	0E5E6: 88 1E 28 05               mov         byte ptr [528h],bl
	0E5EA: 88 1E 3E 05               mov         byte ptr [53Eh],bl
	0E5EE: A0 29 05                  mov         al,[529h]