diff options
Diffstat (limited to 'src/devices/bus/a2bus/a2hsscsi.c')
-rw-r--r-- | src/devices/bus/a2bus/a2hsscsi.c | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/src/devices/bus/a2bus/a2hsscsi.c b/src/devices/bus/a2bus/a2hsscsi.c new file mode 100644 index 00000000000..a292eba7410 --- /dev/null +++ b/src/devices/bus/a2bus/a2hsscsi.c @@ -0,0 +1,323 @@ +// 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 "a2hsscsi.h" +#include "includes/apple2.h" +#include "machine/nscsi_cd.h" +#include "machine/nscsi_hd.h" + +/*************************************************************************** + PARAMETERS +***************************************************************************/ + +//************************************************************************** +// GLOBAL VARIABLES +//************************************************************************** + +const device_type A2BUS_HSSCSI = &device_creator<a2bus_hsscsi_device>; + +#define SCSI_ROM_REGION "scsi_rom" +#define SCSI_BUS_TAG "scsibus" +#define SCSI_5380_TAG "scsibus:7:ncr5380" + +static MACHINE_CONFIG_FRAGMENT( ncr5380 ) + MCFG_DEVICE_CLOCK(10000000) + MCFG_NCR5380N_DRQ_HANDLER(DEVWRITELINE("^^", a2bus_hsscsi_device, drq_w)) +MACHINE_CONFIG_END + +static SLOT_INTERFACE_START( hsscsi_devices ) + SLOT_INTERFACE("cdrom", NSCSI_CDROM) + SLOT_INTERFACE("harddisk", NSCSI_HARDDISK) + SLOT_INTERFACE_INTERNAL("ncr5380", NCR5380N) +SLOT_INTERFACE_END + +static MACHINE_CONFIG_FRAGMENT( hsscsi ) + MCFG_NSCSI_BUS_ADD(SCSI_BUS_TAG) + MCFG_NSCSI_ADD("scsibus:0", hsscsi_devices, 0, false) + MCFG_NSCSI_ADD("scsibus:1", hsscsi_devices, 0, false) + MCFG_NSCSI_ADD("scsibus:2", hsscsi_devices, 0, false) + MCFG_NSCSI_ADD("scsibus:3", hsscsi_devices, 0, false) + MCFG_NSCSI_ADD("scsibus:4", hsscsi_devices, 0, false) + MCFG_NSCSI_ADD("scsibus:5", hsscsi_devices, 0, false) + MCFG_NSCSI_ADD("scsibus:6", hsscsi_devices, "harddisk", false) + MCFG_NSCSI_ADD("scsibus:7", hsscsi_devices, "ncr5380", true) + MCFG_DEVICE_CARD_MACHINE_CONFIG("ncr5380", ncr5380) +MACHINE_CONFIG_END + +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 +***************************************************************************/ + +//------------------------------------------------- +// machine_config_additions - device-specific +// machine configurations +//------------------------------------------------- + +machine_config_constructor a2bus_hsscsi_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( hsscsi ); +} + +//------------------------------------------------- +// rom_region - device-specific ROM region +//------------------------------------------------- + +const 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 *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_ncr5380(*this, SCSI_5380_TAG), + m_scsibus(*this, SCSI_BUS_TAG) +{ +} + +a2bus_hsscsi_device::a2bus_hsscsi_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, A2BUS_HSSCSI, "Apple II High-Speed SCSI Card", tag, owner, clock, "a2hsscsi", __FILE__), + device_a2bus_card_interface(mconfig, *this), + m_ncr5380(*this, SCSI_5380_TAG), + m_scsibus(*this, SCSI_BUS_TAG) +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void a2bus_hsscsi_device::device_start() +{ + // set_a2bus_device makes m_slot valid + set_a2bus_device(); + + m_rom = device().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 a2bus_hsscsi_device::read_c0nx(address_space &space, UINT8 offset) +{ + switch (offset) + { + case 0: + case 1: + case 2: + case 3: + case 4: + case 5: + case 6: + case 7: +// printf("Read 5380 @ %x\n", offset); + return m_ncr5380->read(space, 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: + printf("Read c0n%x (PC=%x)\n", offset, space.device().safe_pc()); + break; + } + + return 0xff; +} + + +/*------------------------------------------------- + write_c0nx - called for writes to this card's c0nx space +-------------------------------------------------*/ + +void a2bus_hsscsi_device::write_c0nx(address_space &space, UINT8 offset, UINT8 data) +{ + switch (offset) + { + case 0: + case 1: + case 2: + case 3: + case 4: + case 5: + case 6: + case 7: +// printf("%02x to 5380 reg %x\n", data, offset); + m_ncr5380->write(space, 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 + printf("%02x to DMA enable/reset\n", data); + if (data & 0x2) + { + // printf("Resetting SCSI: %02x at %x\n", data, space.device().safe_pc()); + m_ncr5380->reset(); + } + break; + + case 0xe: + m_c0ne = data; + m_rombank = (data & 0x1f) * 0x400; + printf("c0ne to %x (ROM bank %x)\n", data & 0x1f, m_rombank); + break; + + case 0xf: + m_c0nf = data; + m_rambank = (data & 0x7) * 0x400; + printf("c0nf to %x (RAM bank %x)\n", data & 0x7, m_rambank); + break; + + default: + printf("Write %02x to c0n%x (PC=%x)\n", data, offset, space.device().safe_pc()); + break; + } +} + +/*------------------------------------------------- + read_cnxx - called for reads from this card's cnxx space +-------------------------------------------------*/ + +UINT8 a2bus_hsscsi_device::read_cnxx(address_space &space, UINT8 offset) +{ + // one slot image at the start of the ROM, it appears + return m_rom[offset]; +} + +void a2bus_hsscsi_device::write_cnxx(address_space &space, UINT8 offset, UINT8 data) +{ +// printf("Write %02x to cn%02x (PC=%x)\n", data, offset, space.device().safe_pc()); +} + +/*------------------------------------------------- + read_c800 - called for reads from this card's c800 space +-------------------------------------------------*/ + +UINT8 a2bus_hsscsi_device::read_c800(address_space &space, UINT16 offset) +{ + // bankswitched RAM at c800-cbff + // bankswitched ROM at cc00-cfff + if (offset < 0x400) + { +// printf("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(address_space &space, UINT16 offset, UINT8 data) +{ + if (offset < 0x400) + { +// printf("%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); +} |