Test ROM to find initial parameters for Gameboy games (in particular for Pokemon RNG manip searching). The ROM will output values that look like this:

1100 1500 0008 007C
Div: 2E
subDiv (/4): 1A
LY: 93
subLy (/4): 6C
Passed

All of these values should be for when the game gets control with PC = 0100. The first line is the registers: AF BC DE HL. After that are the values of the divider register and the number of (machine) cycles toward the next divider increment. To convert to a clock cycle number, multiply Div by 256 and subDiv by 4 before adding. So in this case, 0x2E * 256 + 0x1A * 4

Finally, there are the LY values, which work very similarly to the divider values, except that LY is on a 456 clock cycle pattern. So you want to multiply LY by 456 instead of 256. In this case: 0x93 * 456 + 0x6C * 4.

Note that the bootrom inspects the ROM header, so ensure that the header matches the game that you want parameters for.

Known Hardware Outputs

So far the RNG for 3DSVC and SGB has not been replicated with these parameters.

Pokemon Red

GBA

1100 1500 0008 007C
Div: 2E
subDiv (/4): 1A
LY: 93
subLY (/4): 6C
Passed

GBC

1180 1400 0008 007C
Div: 2E
subDiv (/4): 19
LY: 93
subLy (/4): 6B
Passed

DMG

0190 0013 00D8 014D
Div: AB
subDiv (/4): 33
LY: 99
subLy (/4): 64
Passed

MGB

FF90 0013 00D8 014D
Div: AB
subDiv (/4): 33
LY: 99
subLy (/4): 64
Passed

SGB

0100 0014 0000 C060
Div: D8
subDiv (/4): 13
LY: 99
subLY (/4): 25
Passed

3DS VC

01B0 0013 00D8 014D
Div: 26
subDiv (/4): 1C
LY: 93
subLY (/4): 70
Passed

Pokemon Blue

GBA

1100 6200 0008 007C
Div: 37
subDiv (/4): 1C
LY: 93
subLY (/4): 44
Passed

GBC

1180 6100 0008 007C
Div: 37
subDiv (/4): 1B
LY: 93
subLY (/4): 43
Passed

DMG

01B0 0013 00D8 014D
Div: AB
subDiv (/4): 33
LY: 99
subLY (/4): 64
Passed

MGB

FFB0 0013 00D8 014D
Div: AB
subDiv (/4): 33
LY: 99
subLY (/4): 64
Passed

SGB

0100 0014 0000 C060
Div: D8
subDiv (/4): 17
LY: 99
subLY (/4): 29
Passed

3DS VC

01B0 0013 00D8 014D
Div: 26
subDiv (/4): 1C
LY: 93
subLY (/4): 70
Passed