diff options
author | 2021-06-10 09:23:47 -0800 | |
---|---|---|
committer | 2021-06-10 13:23:47 -0400 | |
commit | ad3e1a29c39557b116ed4b868d3e8ed877aa5af5 (patch) | |
tree | 850a46b7ca6c9a2471711d2af6d40b045e803ae8 /src/devices/bus/nes/act53.cpp | |
parent | a2d5ae4e97d160e13b9cd950f55b74ee75c5db89 (diff) |
nes.xml: add Action 53 based games (#8158)
* nes.xml: add Action 53 based games
New working software list additions
-----------------------------------
Streemerz - Action 53 Function 16 Volume 1 (R.C.#2) [Damian Yerrick, NESDev]
Double Action 53 Volume 2 (R.C.#2) [Damian Yerrick, NESDev]
Action 53 Vol. 3 - Revenge of the Twins [Damian Yerrick, NESDev]
action53.cpp:
* on start up point prg to correct final bank based on cart size
* allow full 9-bit bank select per the spec
* switch to shorter type names, u8 etc
Co-authored-by: 0kmg <0kmg@users.noreply.github.com>
Diffstat (limited to 'src/devices/bus/nes/act53.cpp')
-rw-r--r-- | src/devices/bus/nes/act53.cpp | 66 |
1 files changed, 28 insertions, 38 deletions
diff --git a/src/devices/bus/nes/act53.cpp b/src/devices/bus/nes/act53.cpp index 2a441c36153..0576f36a06c 100644 --- a/src/devices/bus/nes/act53.cpp +++ b/src/devices/bus/nes/act53.cpp @@ -32,7 +32,7 @@ DEFINE_DEVICE_TYPE(NES_ACTION53, nes_action53_device, "nes_action53", "NES Cart Action 53 PCB") -nes_action53_device::nes_action53_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) +nes_action53_device::nes_action53_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) : nes_nrom_device(mconfig, NES_ACTION53, tag, owner, clock) , m_sel(0) { @@ -45,17 +45,21 @@ void nes_action53_device::device_start() common_start(); save_item(NAME(m_sel)); save_item(NAME(m_reg)); - m_reg[0] = 0x00; - m_reg[1] = 0x0f; - m_reg[2] = 0x00; - m_reg[3] = 0x3f; +} + +void nes_action53_device::pcb_start(running_machine &machine, u8 *ciram_ptr, bool cart_mounted) +{ + device_nes_cart_interface::pcb_start(machine, ciram_ptr, cart_mounted); + // at power on last 16K of ROM is mapped to $C000-$FFFF + m_reg[0] = m_reg[1] = m_reg[2] = 0; + m_reg[3] = (m_prg_chunks - 1) >> 1; + update_prg(); } void nes_action53_device::pcb_reset() { m_chr_source = m_vrom_chunks ? CHRROM : CHRRAM; // register content is not touched by reset - update_prg(); } @@ -79,7 +83,7 @@ void nes_action53_device::pcb_reset() R:$80 is clear R:$01: [...M PPPP] - P = PRG Reg + P = Inner PRG Reg M = Mirroring This bit overwrites bit 0 of R:$80, but only if bit 1 of R:$80 is clear @@ -97,7 +101,7 @@ void nes_action53_device::pcb_reset() %10 = Vert %11 = Horz - R:$81: [..BB BBBB] + R:$81: [BBBB BBBB] Outer PRG Reg @@ -105,34 +109,20 @@ void nes_action53_device::pcb_reset() void nes_action53_device::update_prg() { - uint8_t prg_lo, prg_hi, helper; - uint8_t out = (m_reg[3] & 0x3f) << 1; // Outer PRG reg - uint8_t size = (m_reg[2] & 0x30) >> 4; // Game size - uint8_t mask = (1 << (size + 1)) - 1; // Bits to be taken from PRG reg - - if (!BIT(m_reg[2], 3)) - { - helper = (out & ~mask) | ((m_reg[1] << 1) & mask); - //32K mode - prg_lo = (helper & 0xfe); - prg_hi = (helper | 0x01); - } - else - { - helper = (out & ~mask) | (m_reg[1] & mask); - if (BIT(m_reg[2], 2)) - { - //16K mode with fixed HI - prg_lo = helper; - prg_hi = (out | 0x01); - } - else - { - //16K mode with fixed LO - prg_lo = (out & 0xfe); - prg_hi = helper; - } - } + u16 prg_lo, prg_hi; + u8 size = (m_reg[2] & 0x30) >> 4; // Game size + u16 mask = ~0 << (size + 1); // Bits to be taken from PRG regs + u8 b32k = !BIT(m_reg[2], 3); // 32K mode bit + u16 outer = m_reg[3] << 1; // Outer PRG reg bits + u8 inner = (m_reg[1] << b32k) & ~mask; // Inner PRG reg bits + + prg_hi = prg_lo = (outer & mask) | inner; + if (b32k) // 32K mode + prg_hi++; + else if (BIT(m_reg[2], 2)) // 16K mode with fixed HI + prg_hi = ++outer; + else // 16K mode with fixed LO + prg_lo = outer; // printf("banks : 0x%2X - 0x%2X\n", prg_lo, prg_hi); prg16_89ab(prg_lo); @@ -158,7 +148,7 @@ void nes_action53_device::update_mirr() } } -void nes_action53_device::write_l(offs_t offset, uint8_t data) +void nes_action53_device::write_l(offs_t offset, u8 data) { LOG_MMC(("action 53 write_l, offset: %04x, data: %02x\n", offset, data)); offset += 0x100; @@ -167,7 +157,7 @@ void nes_action53_device::write_l(offs_t offset, uint8_t data) } -void nes_action53_device::write_h(offs_t offset, uint8_t data) +void nes_action53_device::write_h(offs_t offset, u8 data) { LOG_MMC(("action 53 write_h, offset: %04x, data: %02x\n", offset, data)); |