// 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; #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, std::string 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_rom(nullptr), m_started(false), m_ack(0), m_irqenable(false), m_autostrobe(false), m_timer(nullptr) { } a2bus_pic_device::a2bus_pic_device(const machine_config &mconfig, device_type type, const char *name, std::string 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_rom(nullptr), m_started(false), m_ack(0), m_irqenable(false), m_autostrobe(false), m_timer(nullptr) { } //------------------------------------------------- // 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, nullptr); 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); } }