diff options
Diffstat (limited to 'src/devices/bus/c64/ieee488.cpp')
-rw-r--r-- | src/devices/bus/c64/ieee488.cpp | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/src/devices/bus/c64/ieee488.cpp b/src/devices/bus/c64/ieee488.cpp new file mode 100644 index 00000000000..4b41417b42d --- /dev/null +++ b/src/devices/bus/c64/ieee488.cpp @@ -0,0 +1,249 @@ +// license:BSD-3-Clause +// copyright-holders:Curt Coder +/********************************************************************** + + Commodore IEEE-488 cartridge emulation + +**********************************************************************/ + +#include "ieee488.h" + + + +//************************************************************************** +// MACROS/CONSTANTS +//************************************************************************** + +#define MOS6525_TAG "u3" + + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +const device_type C64_IEEE488 = &device_creator<c64_ieee488_device>; + + +//------------------------------------------------- +// tpi6525_interface tpi_intf +//------------------------------------------------- + +READ8_MEMBER( c64_ieee488_device::tpi_pa_r ) +{ + /* + + bit description + + PA0 + PA1 + PA2 REN + PA3 ATN + PA4 DAV + PA5 EOI + PA6 NDAC + PA7 NRFD + + */ + + UINT8 data = 0; + + data |= m_bus->ren_r() << 2; + data |= m_bus->atn_r() << 3; + data |= m_bus->dav_r() << 4; + data |= m_bus->eoi_r() << 5; + data |= m_bus->ndac_r() << 6; + data |= m_bus->nrfd_r() << 7; + + return data; +} + +WRITE8_MEMBER( c64_ieee488_device::tpi_pa_w ) +{ + /* + + bit description + + PA0 U4 DC + PA1 U4/U5 TE + PA2 REN + PA3 ATN + PA4 DAV + PA5 EOI + PA6 NDAC + PA7 NRFD + + */ + + m_bus->ren_w(BIT(data, 2)); + m_bus->atn_w(BIT(data, 3)); + m_bus->dav_w(BIT(data, 4)); + m_bus->eoi_w(BIT(data, 5)); + m_bus->ndac_w(BIT(data, 6)); + m_bus->nrfd_w(BIT(data, 7)); +} + +READ8_MEMBER( c64_ieee488_device::tpi_pc_r ) +{ + /* + + bit description + + PC0 IFC + PC1 SRQ + PC2 + PC3 + PC4 + PC5 + PC6 + PC7 slot _EXROM + + */ + + UINT8 data = 0; + + data |= m_bus->ifc_r(); + data |= m_bus->srq_r() << 1; + + data |= m_exp->exrom_r(offset, 1, 1, 1, 0) << 7; + + return data; +} + +WRITE8_MEMBER( c64_ieee488_device::tpi_pc_w ) +{ + /* + + bit description + + PC0 IFC + PC1 SRQ + PC2 + PC3 C64 _EXROM + PC4 _ROML select + PC5 + PC6 + PC7 + + */ + + m_bus->ifc_w(BIT(data, 0)); + m_bus->srq_w(BIT(data, 1)); + + m_exrom = !BIT(data, 3); + + m_roml_sel = BIT(data, 4); +} + +//------------------------------------------------- +// MACHINE_CONFIG_FRAGMENT( c64_ieee488 ) +//------------------------------------------------- + +static MACHINE_CONFIG_FRAGMENT( c64_ieee488 ) + MCFG_DEVICE_ADD(MOS6525_TAG, TPI6525, 0) + MCFG_TPI6525_IN_PA_CB(READ8(c64_ieee488_device, tpi_pa_r)) + MCFG_TPI6525_OUT_PA_CB(WRITE8(c64_ieee488_device, tpi_pa_w)) + MCFG_TPI6525_IN_PB_CB(DEVREAD8(IEEE488_TAG, ieee488_device, dio_r)) + MCFG_TPI6525_OUT_PB_CB(DEVWRITE8(IEEE488_TAG, ieee488_device, dio_w)) + MCFG_TPI6525_IN_PC_CB(READ8(c64_ieee488_device, tpi_pc_r)) + MCFG_TPI6525_OUT_PC_CB(WRITE8(c64_ieee488_device, tpi_pc_w)) + + MCFG_CBM_IEEE488_ADD(NULL) + MCFG_C64_PASSTHRU_EXPANSION_SLOT_ADD() +MACHINE_CONFIG_END + + +//------------------------------------------------- +// machine_config_additions - device-specific +// machine configurations +//------------------------------------------------- + +machine_config_constructor c64_ieee488_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( c64_ieee488 ); +} + + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// c64_ieee488_device - constructor +//------------------------------------------------- + +c64_ieee488_device::c64_ieee488_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, C64_IEEE488, "IEEE-488", tag, owner, clock, "c64_ieee488", __FILE__), + device_c64_expansion_card_interface(mconfig, *this), + m_tpi(*this, MOS6525_TAG), + m_bus(*this, IEEE488_TAG), + m_exp(*this, C64_EXPANSION_SLOT_TAG), + m_roml_sel(1) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void c64_ieee488_device::device_start() +{ +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void c64_ieee488_device::device_reset() +{ + m_exrom = 0; +} + + +//------------------------------------------------- +// c64_cd_r - cartridge data read +//------------------------------------------------- + +UINT8 c64_ieee488_device::c64_cd_r(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2) +{ + data = m_exp->cd_r(space, offset, data, sphi2, ba, roml, romh, io1, io2); + + if (!roml && m_roml_sel) + { + data = m_roml[offset & 0xfff]; + } + else if (!io2) + { + data = m_tpi->read(space, offset & 0x07); + } + + return data; +} + + +//------------------------------------------------- +// c64_cd_w - cartridge data write +//------------------------------------------------- + +void c64_ieee488_device::c64_cd_w(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2) +{ + if (!io2) + { + m_tpi->write(space, offset & 0x07, data); + } + + m_exp->cd_w(space, offset, data, sphi2, ba, roml, romh, io1, io2); +} + + +//------------------------------------------------- +// c64_game_r - GAME read +//------------------------------------------------- + +int c64_ieee488_device::c64_game_r(offs_t offset, int sphi2, int ba, int rw) +{ + return m_exp->game_r(offset, sphi2, ba, rw, m_slot->hiram()); +} |