diff options
Diffstat (limited to 'src/devices/bus/a2bus/a2pic.c')
-rw-r--r-- | src/devices/bus/a2bus/a2pic.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/src/devices/bus/a2bus/a2pic.c b/src/devices/bus/a2bus/a2pic.c new file mode 100644 index 00000000000..daede92b119 --- /dev/null +++ b/src/devices/bus/a2bus/a2pic.c @@ -0,0 +1,290 @@ +// license:BSD-3-Clause +// copyright-holders:R. Belmont +/********************************************************************* + + a2pic.c + + Apple II Parallel Interface Card (670-0021) + +*********************************************************************/ + +#include "a2pic.h" + +/*************************************************************************** + PARAMETERS +***************************************************************************/ + +//************************************************************************** +// GLOBAL VARIABLES +//************************************************************************** + +const device_type A2BUS_PIC = &device_creator<a2bus_pic_device>; + +#define PIC_ROM_REGION "pic_rom" +#define PIC_CENTRONICS_TAG "pic_ctx" + +MACHINE_CONFIG_FRAGMENT( pic ) + MCFG_CENTRONICS_ADD(PIC_CENTRONICS_TAG, centronics_devices, "printer") + MCFG_CENTRONICS_DATA_INPUT_BUFFER("ctx_data_in") + MCFG_CENTRONICS_ACK_HANDLER(WRITELINE(a2bus_pic_device, ack_w)) + + MCFG_DEVICE_ADD("ctx_data_in", INPUT_BUFFER, 0) + MCFG_CENTRONICS_OUTPUT_LATCH_ADD("ctx_data_out", PIC_CENTRONICS_TAG) +MACHINE_CONFIG_END + +ROM_START( pic ) + ROM_REGION(0x000200, PIC_ROM_REGION, 0) + ROM_LOAD( "341-0057.bin", 0x000000, 0x000200, CRC(0d2d84ee) SHA1(bfc5b863d37e59875a6159528eb0f2b6082063b5) ) +ROM_END + +static INPUT_PORTS_START( pic ) + PORT_START("DSW1") + PORT_DIPNAME( 0x07, 0x00, "Strobe length (SW1-3)" ) + PORT_DIPSETTING( 0x00, "1 microsecond" ) + PORT_DIPSETTING( 0x01, "3 microseconds" ) + PORT_DIPSETTING( 0x02, "5 microseconds" ) + PORT_DIPSETTING( 0x03, "7 microseconds" ) + PORT_DIPSETTING( 0x04, "9 microseconds" ) + PORT_DIPSETTING( 0x05, "11 microseconds" ) + PORT_DIPSETTING( 0x06, "13 microseconds" ) + PORT_DIPSETTING( 0x07, "15 microseconds" ) + + PORT_DIPNAME( 0x08, 0x00, "Strobe polarity (SW4)" ) + PORT_DIPSETTING( 0x00, "Positive" ) + PORT_DIPSETTING( 0x08, "Negative" ) + + PORT_DIPNAME( 0x10, 0x00, "Acknowledge polarity (SW5)" ) + PORT_DIPSETTING( 0x00, "Positive" ) + PORT_DIPSETTING( 0x10, "Negative" ) + + PORT_DIPNAME( 0x20, 0x20, "Firmware (SW6)" ) + PORT_DIPSETTING( 0x00, "Parallel Printer (341-0005)" ) + PORT_DIPSETTING( 0x20, "Centronics (341-0019)" ) + + PORT_DIPNAME( 0x40, 0x00, "Use interrupts (SW7)" ) + PORT_DIPSETTING( 0x00, "Off" ) + PORT_DIPSETTING( 0x40, "On" ) +INPUT_PORTS_END + +//------------------------------------------------- +// input_ports - device-specific input ports +//------------------------------------------------- + +ioport_constructor a2bus_pic_device::device_input_ports() const +{ + return INPUT_PORTS_NAME( pic ); +} + +//------------------------------------------------- +// machine_config_additions - device-specific +// machine configurations +//------------------------------------------------- + +machine_config_constructor a2bus_pic_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( pic ); +} + +//------------------------------------------------- +// rom_region - device-specific ROM region +//------------------------------------------------- + +const rom_entry *a2bus_pic_device::device_rom_region() const +{ + return ROM_NAME( pic ); +} + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +a2bus_pic_device::a2bus_pic_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, A2BUS_PIC, "Apple Parallel Interface Card", tag, owner, clock, "a2pic", __FILE__), + device_a2bus_card_interface(mconfig, *this), + m_dsw1(*this, "DSW1"), + m_ctx(*this, PIC_CENTRONICS_TAG), + m_ctx_data_in(*this, "ctx_data_in"), + m_ctx_data_out(*this, "ctx_data_out"), + m_started(false) +{ +} + +a2bus_pic_device::a2bus_pic_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source) : + device_t(mconfig, type, name, tag, owner, clock, shortname, source), + device_a2bus_card_interface(mconfig, *this), + m_dsw1(*this, "DSW1"), + m_ctx(*this, PIC_CENTRONICS_TAG), + m_ctx_data_in(*this, "ctx_data_in"), + m_ctx_data_out(*this, "ctx_data_out"), + m_started(false) +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void a2bus_pic_device::device_start() +{ + // set_a2bus_device makes m_slot valid + set_a2bus_device(); + + m_rom = device().machine().root_device().memregion(this->subtag(PIC_ROM_REGION).c_str())->base(); + + m_timer = timer_alloc(0, NULL); + m_timer->adjust(attotime::never); + + save_item(NAME(m_ack)); + save_item(NAME(m_irqenable)); + save_item(NAME(m_autostrobe)); +} + +void a2bus_pic_device::device_reset() +{ + m_started = true; + m_ack = 0; + m_irqenable = false; + m_autostrobe = false; + lower_slot_irq(); + m_timer->adjust(attotime::never); + + // set initial state of the strobe line depending on the dipswitch + clear_strobe(); +} + +void a2bus_pic_device::device_timer(emu_timer &timer, device_timer_id tid, int param, void *ptr) +{ + clear_strobe(); + + m_timer->adjust(attotime::never); +} + +/*------------------------------------------------- + read_cnxx - called for reads from this card's cnxx space +-------------------------------------------------*/ + +UINT8 a2bus_pic_device::read_cnxx(address_space &space, UINT8 offset) +{ + m_autostrobe = true; + + if (m_dsw1->read() & 0x20) + { + return m_rom[(offset&0xff) | 0x100]; + } + + return m_rom[(offset&0xff)]; +} + +/*------------------------------------------------- + read_c0nx - called for reads from this card's c0nx space +-------------------------------------------------*/ + +UINT8 a2bus_pic_device::read_c0nx(address_space &space, UINT8 offset) +{ + switch (offset) + { + case 3: + return m_ctx_data_in->read(); + + case 4: + return m_ack; + + case 6: // does reading this really work? + m_irqenable = true; + break; + + case 7: + m_irqenable = false; + m_autostrobe = false; + lower_slot_irq(); + break; + + } + + return 0; +} + +/*------------------------------------------------- + write_c0nx - called for writes to this card's c0nx space +-------------------------------------------------*/ + +void a2bus_pic_device::write_c0nx(address_space &space, UINT8 offset, UINT8 data) +{ + switch (offset) + { + case 0: // set data out and send a strobe + m_ctx_data_out->write(data); + + if (m_autostrobe) + { + start_strobe(); + } + break; + + case 2: // send a strobe + start_strobe(); + break; + + case 6: // enable interrupt on ACK + m_irqenable = true; + break; + + case 7: // disable and acknowledge IRQ, reset ACK flip-flop, disable autostrobe + m_irqenable = false; + m_autostrobe = false; + lower_slot_irq(); + break; + } +} + +WRITE_LINE_MEMBER( a2bus_pic_device::ack_w ) +{ + if (m_started) + { + UINT8 dsw1 = m_dsw1->read(); + + if (dsw1 & 0x10) // negative polarity + { + m_ack = (state == ASSERT_LINE) ? 0x00 : 0x80; + } + else + { + m_ack = (state == ASSERT_LINE) ? 0x80 : 0x00; + } + + m_ack |= 0x40; // set ACK flip-flop + + if ((dsw1 & 0x40) && (m_irqenable)) + { + raise_slot_irq(); + } + } +} + +void a2bus_pic_device::start_strobe() +{ + int usec = ((m_dsw1->read() & 7) * 2) + 1; // strobe length in microseconds + + if (m_dsw1->read() & 0x8) // negative polarity + { + m_ctx->write_strobe(CLEAR_LINE); + } + else + { + m_ctx->write_strobe(ASSERT_LINE); + } + + m_timer->adjust(attotime::from_usec(usec), 0, attotime::never); +} + +void a2bus_pic_device::clear_strobe() +{ + if (m_dsw1->read() & 0x8) // negative polarity + { + m_ctx->write_strobe(ASSERT_LINE); + } + else + { + m_ctx->write_strobe(CLEAR_LINE); + } +} |