// license:BSD-3-Clause // copyright-holders:R. Belmont /********************************************************************* a2hsscsi.c Implementation of the Apple II High Speed SCSI Card This uses an ASIC called "Sandwich II"; the card itself is sometimes known as "Cocoon". Notes: C0n0-C0n7 = NCR5380 registers in normal order C0n8 = DMA address low C0n9 = DMA address high C0nA = DMA count low C0nB = DMA count high C0nC = DMA control C0nD = Enable DMA / reset 5380 C0nE = Priority (read bits 5-7) / Fire watchdog (write bit 7) / RAM bank (write bits 0-3) C0nF = DMA speed (bit 7 = 0 for fast, 1 for slow) / ROM bank (write bits 0-4) DMA control register (C0nC): 0x01 = pseudo-DMA enable 0x02 = DMA enable 0x04 = test mode 0x08 = disable stop-DMA-on-IRQ 0x10 = DMA direction (read only) 0x20 = 5380 IRQ enable 0x40 = system DMA status (read only) 0x80 = DMA stopped due to IRQ Enable DMA / reset 5380 register (C0nD): 0x01 = Resume DMA after rollover or IRQ 0x02 = Reset the 5380 0x40 = Clear test mode 0x80 = Set test mode *********************************************************************/ #include "emu.h" #include "a2hsscsi.h" #include "bus/nscsi/devices.h" /*************************************************************************** PARAMETERS ***************************************************************************/ //************************************************************************** // GLOBAL VARIABLES //************************************************************************** DEFINE_DEVICE_TYPE(A2BUS_HSSCSI, a2bus_hsscsi_device, "a2hsscsi", "Apple II High-Speed SCSI Card") #define SCSI_ROM_REGION "scsi_rom" #define SCSI_BUS_TAG "scsibus" #define SCSI_5380_TAG "scsibus:7:ncr5380" ROM_START( hsscsi ) ROM_REGION(0x8000, SCSI_ROM_REGION, 0) ROM_LOAD( "341-0803.bin", 0x0000, 0x8000, CRC(2c15618b) SHA1(7d32227299933bfc1b7f8bc2062906fdfe530674) ) ROM_END /*************************************************************************** FUNCTION PROTOTYPES ***************************************************************************/ //------------------------------------------------- // device_add_mconfig - add device configuration //------------------------------------------------- void a2bus_hsscsi_device::device_add_mconfig(machine_config &config) { NSCSI_BUS(config, m_scsibus); NSCSI_CONNECTOR(config, "scsibus:0", default_scsi_devices, nullptr, false); NSCSI_CONNECTOR(config, "scsibus:1", default_scsi_devices, nullptr, false); NSCSI_CONNECTOR(config, "scsibus:2", default_scsi_devices, nullptr, false); NSCSI_CONNECTOR(config, "scsibus:3", default_scsi_devices, nullptr, false); NSCSI_CONNECTOR(config, "scsibus:4", default_scsi_devices, nullptr, false); NSCSI_CONNECTOR(config, "scsibus:5", default_scsi_devices, nullptr, false); NSCSI_CONNECTOR(config, "scsibus:6", default_scsi_devices, "harddisk", false); NSCSI_CONNECTOR(config, "scsibus:7").option_set("ncr5380", NCR53C80).machine_config([this](device_t *device) { downcast(*device).drq_handler().set(*this, FUNC(a2bus_hsscsi_device::drq_w)); }); } //------------------------------------------------- // rom_region - device-specific ROM region //------------------------------------------------- const tiny_rom_entry *a2bus_hsscsi_device::device_rom_region() const { return ROM_NAME( hsscsi ); } //************************************************************************** // LIVE DEVICE //************************************************************************** a2bus_hsscsi_device::a2bus_hsscsi_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, type, tag, owner, clock), device_a2bus_card_interface(mconfig, *this), m_ncr5380(*this, SCSI_5380_TAG), m_scsibus(*this, SCSI_BUS_TAG), m_rom(nullptr), m_rambank(0), m_rombank(0), m_drq(0), m_bank(0), m_816block(false), m_c0ne(0), m_c0nf(0) { } a2bus_hsscsi_device::a2bus_hsscsi_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : a2bus_hsscsi_device(mconfig, A2BUS_HSSCSI, tag, owner, clock) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void a2bus_hsscsi_device::device_start() { m_rom = machine().root_device().memregion(this->subtag(SCSI_ROM_REGION).c_str())->base(); memset(m_ram, 0, 8192); save_item(NAME(m_ram)); save_item(NAME(m_rambank)); save_item(NAME(m_rombank)); save_item(NAME(m_bank)); save_item(NAME(m_drq)); save_item(NAME(m_816block)); } void a2bus_hsscsi_device::device_reset() { m_rambank = 0; m_rombank = 0; m_c0ne = m_c0nf = 0; m_816block = false; } /*------------------------------------------------- read_c0nx - called for reads from this card's c0nx space -------------------------------------------------*/ uint8_t a2bus_hsscsi_device::read_c0nx(uint8_t offset) { switch (offset) { case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: // logerror("Read 5380 @ %x\n", offset); return m_ncr5380->read(offset); case 0xc: return 0x00; // indicate watchdog? case 0xe: // code at cf32 wants to RMW this without killing the ROM bank return m_c0ne; case 0xf: return m_c0nf; default: logerror("Read c0n%x (%s)\n", offset, machine().describe_context()); break; } return 0xff; } /*------------------------------------------------- write_c0nx - called for writes to this card's c0nx space -------------------------------------------------*/ void a2bus_hsscsi_device::write_c0nx(uint8_t offset, uint8_t data) { switch (offset) { case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: // logerror("%02x to 5380 reg %x\n", data, offset); m_ncr5380->write(offset, data); break; #if 0 case 8: // DMA address low break; case 9: // DMA address high break; case 0xa: // DMA count low break; case 0xb: // DMA count high break; case 0xc: // DMA control break; #endif case 0xd: // DMA enable / reset logerror("%02x to DMA enable/reset\n", data); if (data & 0x2) { // logerror("Resetting SCSI: %02x at %s\n", data, machine().describe_context()); m_ncr5380->reset(); } break; case 0xe: m_c0ne = data; m_rombank = (data & 0x1f) * 0x400; logerror("c0ne to %x (ROM bank %x)\n", data & 0x1f, m_rombank); break; case 0xf: m_c0nf = data; m_rambank = (data & 0x7) * 0x400; logerror("c0nf to %x (RAM bank %x)\n", data & 0x7, m_rambank); break; default: logerror("Write %02x to c0n%x (%s)\n", data, offset, machine().describe_context()); break; } } /*------------------------------------------------- read_cnxx - called for reads from this card's cnxx space -------------------------------------------------*/ uint8_t a2bus_hsscsi_device::read_cnxx(uint8_t offset) { // one slot image at the start of the ROM, it appears return m_rom[offset]; } void a2bus_hsscsi_device::write_cnxx(uint8_t offset, uint8_t data) { // logerror("Write %02x to cn%02x (PC=%x)\n", data, offset, machine().describe_context()); } /*------------------------------------------------- read_c800 - called for reads from this card's c800 space -------------------------------------------------*/ uint8_t a2bus_hsscsi_device::read_c800(uint16_t offset) { // bankswitched RAM at c800-cbff // bankswitched ROM at cc00-cfff if (offset < 0x400) { // logerror("Read RAM at %x = %02x\n", offset+m_rambank, m_ram[offset + m_rambank]); if (m_816block) { return m_ncr5380->dma_r(); } return m_ram[offset + m_rambank]; } else { return m_rom[(offset-0x400) + m_rombank]; } } /*------------------------------------------------- write_c800 - called for writes to this card's c800 space -------------------------------------------------*/ void a2bus_hsscsi_device::write_c800(uint16_t offset, uint8_t data) { if (offset < 0x400) { // logerror("%02x to RAM at %x\n", data, offset+m_rambank); if (m_816block) { m_ncr5380->dma_w(data); } else { m_ram[offset + m_rambank] = data; } } } WRITE_LINE_MEMBER( a2bus_hsscsi_device::drq_w ) { m_drq = (state ? 0x80 : 0x00); }