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-rw-r--r--src/devices/bus/a2bus/a2pic.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/src/devices/bus/a2bus/a2pic.c b/src/devices/bus/a2bus/a2pic.c
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index 00000000000..daede92b119
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+++ b/src/devices/bus/a2bus/a2pic.c
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+// 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);
+ }
+}