diff options
Diffstat (limited to 'src/emu/bus/nes/act53.c')
-rw-r--r-- | src/emu/bus/nes/act53.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/src/emu/bus/nes/act53.c b/src/emu/bus/nes/act53.c index 5ee6293ac68..6914d1137df 100644 --- a/src/emu/bus/nes/act53.c +++ b/src/emu/bus/nes/act53.c @@ -7,7 +7,7 @@ Visit http://mamedev.org for licensing and usage restrictions. - Here we emulate the Multi-Discrete PCB designed by Tepples for + Here we emulate the Multi-Discrete PCB designed by Tepples for this homebew multicart [mapper 28] ***********************************************************************************************************/ @@ -67,23 +67,23 @@ void nes_action53_device::pcb_reset() Board ACTION 53 - In MESS: *VERY* preliminary support. - + In MESS: *VERY* preliminary support. + This board uses 4 registers (reg is selected by writes to 0x5xxx) Info from nesdev wiki - + R:$00: [...M ..CC] C = CHR Reg M = Mirroring This bit overwrites bit 0 of R:$80, but only if bit 1 of R:$80 is clear - + R:$01: [...M PPPP] P = PRG Reg M = Mirroring This bit overwrites bit 0 of R:$80, but only if bit 1 of R:$80 is clear - + R:$80: [..GG PSMM] G = Game Size (0=32K, 1=64K, 2=128K, 3=256K) P = PRG Size (0=32k mode, 1=16k mode) @@ -106,9 +106,9 @@ void nes_action53_device::pcb_reset() void nes_action53_device::update_prg() { UINT8 prg_lo = 0, prg_hi = 0, helper = 0; - UINT8 out = (m_reg[3] & 0x3f) << 1; // Outer PRG reg - UINT8 size = (m_reg[2] & 0x30) >> 4; // Game size - UINT8 mask = (1 << (size + 1)) - 1; // Bits to be taken from PRG reg + UINT8 out = (m_reg[3] & 0x3f) << 1; // Outer PRG reg + UINT8 size = (m_reg[2] & 0x30) >> 4; // Game size + UINT8 mask = (1 << (size + 1)) - 1; // Bits to be taken from PRG reg if (!BIT(m_reg[2], 3)) { @@ -134,7 +134,7 @@ void nes_action53_device::update_prg() } } -// printf("banks : 0x%2X - 0x%2X\n", prg_lo, prg_hi); +// printf("banks : 0x%2X - 0x%2X\n", prg_lo, prg_hi); prg16_89ab(prg_lo); prg16_cdef(prg_hi); } |