diff options
Diffstat (limited to 'src/devices/bus/c64/c128_partner.c')
-rw-r--r-- | src/devices/bus/c64/c128_partner.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/src/devices/bus/c64/c128_partner.c b/src/devices/bus/c64/c128_partner.c new file mode 100644 index 00000000000..00f5a8e2cb9 --- /dev/null +++ b/src/devices/bus/c64/c128_partner.c @@ -0,0 +1,250 @@ +// license:BSD-3-Clause +// copyright-holders:Curt Coder +/********************************************************************** + + Timeworks PARTNER 128 cartridge emulation + +**********************************************************************/ + +/* + + PCB Layout + ---------- + + |---------------| + |LS74 SW * | + |LS09 LS273| + |LS139 RAM | + |LS133 | + | LS240 | + |LS33 ROM | + |LS09 | + ||||||||||||||| + + ROM - Toshiba TMM24128AP 16Kx8 EPROM (blank label) + RAM - Sony CXK5864PN-15L 8Kx8 SRAM + SW - push button switch + * - solder point for joystick port dongle + +*/ + +#include "c128_partner.h" + + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +const device_type C128_PARTNER = &device_creator<partner128_t>; + + +//------------------------------------------------- +// INPUT_PORTS( c128_partner ) +//------------------------------------------------- + +WRITE_LINE_MEMBER( partner128_t::nmi_w ) +{ + if (state) + { + m_ls74_q1 = 1; + } +} + +static INPUT_PORTS_START( c128_partner ) + PORT_START("NMI") + PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("Menu") PORT_CODE(KEYCODE_END) PORT_WRITE_LINE_DEVICE_MEMBER(DEVICE_SELF, partner128_t, nmi_w) +INPUT_PORTS_END + + +//------------------------------------------------- +// input_ports - device-specific input ports +//------------------------------------------------- + +ioport_constructor partner128_t::device_input_ports() const +{ + return INPUT_PORTS_NAME( c128_partner ); +} + + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// partner128_t - constructor +//------------------------------------------------- + +partner128_t::partner128_t(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, C128_PARTNER, "PARTNER 128", tag, owner, clock, "c128_partner", __FILE__), + device_c64_expansion_card_interface(mconfig, *this), + //device_vcs_control_port_interface(mconfig, *this), + m_ram(*this, "ram"), + m_ram_a12_a7(0), + m_ls74_cd(0), + m_ls74_q1(0), + m_ls74_q2(0), + m_joyb2(0) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void partner128_t::device_start() +{ + // allocate memory + m_ram.allocate(0x2000); + + // simulate the 16.7ms pulse from CIA1 PB2 that would arrive thru the joystick port dongle + t_joyb2 = timer_alloc(); + t_joyb2->adjust(attotime::from_msec(16), 0, attotime::from_msec(16)); + + // state saving + save_item(NAME(m_ram_a12_a7)); + save_item(NAME(m_ls74_cd)); + save_item(NAME(m_ls74_q1)); + save_item(NAME(m_ls74_q2)); + save_item(NAME(m_joyb2)); +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void partner128_t::device_reset() +{ + m_ram_a12_a7 = 0; + + m_ls74_cd = 0; + m_ls74_q1 = 0; + m_ls74_q2 = 0; + + nmi_w(CLEAR_LINE); +} + + +//------------------------------------------------- +// device_timer - +//------------------------------------------------- + +void partner128_t::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) +{ + if (m_ls74_cd) + { + m_ls74_q2 = m_ls74_q1; + + nmi_w(m_ls74_q2 ? ASSERT_LINE : CLEAR_LINE); + } +} + + +//------------------------------------------------- +// c64_cd_r - cartridge data read +//------------------------------------------------- + +UINT8 partner128_t::c64_cd_r(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2) +{ + if (!roml) + { + data = m_roml[offset & 0x3fff]; + } + + if (!io1) + { + if (BIT(offset, 7)) + { + data = m_roml[offset & 0x3fff]; + + if (m_ls74_cd) + { + m_ls74_q1 = 0; + } + } + else + { + data = m_ram[(m_ram_a12_a7 << 7) | (offset & 0x7f)]; + } + } + + if (m_ls74_q2 && ((offset & 0xfffa) == 0xfffa)) + { + // override the 8502 NMI/IRQ vectors with 0xdede + data = 0xde; + } + + return data; +} + + +//------------------------------------------------- +// c64_cd_w - cartridge data write +//------------------------------------------------- + +void partner128_t::c64_cd_w(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2) +{ + if (!io1) + { + if (BIT(offset, 7)) + { + /* + + bit description + + 0 RAM A7 + 1 RAM A8 + 2 RAM A9 + 3 RAM A10 + 4 RAM A11 + 5 RAM A12 + 6 LS74 1Cd,2Cd + 7 N/C + + */ + + m_ram_a12_a7 = data & 0x3f; + + m_ls74_cd = BIT(data, 6); + + if (!m_ls74_cd) + { + m_ls74_q1 = 0; + m_ls74_q2 = 0; + + nmi_w(CLEAR_LINE); + } + } + else + { + m_ram[(m_ram_a12_a7 << 7) | (offset & 0x7f)] = data; + } + } + + if (sphi2 && ((offset & 0xfff0) == 0xd600)) + { + m_ram[(m_ram_a12_a7 << 7) | (offset & 0x7f)] = data; + } +} + + +//------------------------------------------------- +// vcs_joy_w - joystick write +//------------------------------------------------- + +void partner128_t::vcs_joy_w(UINT8 data) +{ + int joyb2 = BIT(data, 2); + + if (!m_joyb2 && joyb2 && m_ls74_cd) + { + m_ls74_q2 = m_ls74_q1; + + nmi_w(m_ls74_q2 ? ASSERT_LINE : CLEAR_LINE); + } + + m_joyb2 = joyb2; +} |