// license:BSD-3-Clause // copyright-holders:Curt Coder /********************************************************************** Luxor ABC 1600 Memory Access Controller emulation Copyright MESS Team. Visit http://mamedev.org for licensing and usage restrictions. **********************************************************************/ /* TODO: - segment/page RAM addresses are not correctly decoded, "sas/format/format" can't find the SASI interface because of this forcetask0 1 t0 0 t1 0 t2 0 t3 0 sega19 0 task 0 sega 000 segd 00 pga 008 pgd 4058 virtual 02c730 (should be 004730) */ #include "abc1600mac.h" //************************************************************************** // MACROS / CONSTANTS //************************************************************************** #define LOG 0 #define A0 BIT(offset, 0) #define A1 BIT(offset, 1) #define A2 BIT(offset, 2) #define A4 BIT(offset, 4) #define A7 BIT(offset, 7) #define A8 BIT(offset, 8) #define X11 BIT(offset, 11) #define X12 BIT(offset, 12) #define A17 BIT(offset, 17) #define A18 BIT(offset, 18) #define A19 BIT(offset, 19) #define A10_A9_A8 ((offset >> 8) & 0x07) #define A2_A1_A0 (offset & 0x07) #define A1_A2 ((A1 << 1) | A2) #define A2_A1 ((offset >> 1) & 0x03) #define FC0 BIT(fc, 0) #define FC1 BIT(fc, 1) #define FC2 BIT(fc, 2) #define PAGE_WP BIT(page_data, 14) #define PAGE_NONX BIT(page_data, 15) #define BOOTE BIT(m_task, 6) #define MAGIC BIT(m_task, 7) #define READ_MAGIC !MAGIC //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** const device_type ABC1600_MAC = &device_creator; DEVICE_ADDRESS_MAP_START( map, 8, abc1600_mac_device ) AM_RANGE(0x00000, 0xfffff) AM_READWRITE(read, write) ADDRESS_MAP_END static ADDRESS_MAP_START( program_map, AS_PROGRAM, 8, abc1600_mac_device ) ADDRESS_MAP_END //------------------------------------------------- // ROM( abc1600_mac ) //------------------------------------------------- ROM_START( abc1600_mac ) ROM_REGION( 0x4000, "boot", 0 ) ROM_LOAD( "boot 6490356-04.1f", 0x0000, 0x4000, CRC(9372f6f2) SHA1(86f0681f7ef8dd190b49eda5e781881582e0c2a4) ) ROM_REGION( 0x104, "plds", 0 ) ROM_LOAD( "1022 6490351-01.17e", 0x000, 0x104, CRC(5dd00d43) SHA1(a3871f0d796bea9df8f25d41b3169dd4b8ef65ab) ) // MAC register address decoder ROM_END //------------------------------------------------- // rom_region - device-specific ROM region //------------------------------------------------- const rom_entry *abc1600_mac_device::device_rom_region() const { return ROM_NAME( abc1600_mac ); } //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // abc1600_mac_device - constructor //------------------------------------------------- abc1600_mac_device::abc1600_mac_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : device_t(mconfig, ABC1600_MAC, "ABC 1600 MAC", tag, owner, clock, "abc1600mac", __FILE__), device_memory_interface(mconfig, *this), m_space_config("program", ENDIANNESS_LITTLE, 8, 22, 0, *ADDRESS_MAP_NAME(program_map)), m_rom(*this, "boot"), m_segment_ram(*this, "segment_ram"), m_page_ram(*this, "page_ram") { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void abc1600_mac_device::device_start() { // get the CPU device m_cpu = machine().device(m_cpu_tag); assert(m_cpu != NULL); // allocate memory m_segment_ram.allocate(0x400); m_page_ram.allocate(0x400); // HACK fill segment RAM or abcenix won't boot memset(m_segment_ram, 0xcd, 0x400); // state saving save_item(NAME(m_ifc2)); save_item(NAME(m_task)); save_item(NAME(m_dmamap)); save_item(NAME(m_cause)); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void abc1600_mac_device::device_reset() { // clear task register m_task = 0; } //------------------------------------------------- // memory_space_config - return a description of // any address spaces owned by this device //------------------------------------------------- const address_space_config *abc1600_mac_device::memory_space_config(address_spacenum spacenum) const { return (spacenum == AS_PROGRAM) ? &m_space_config : NULL; } //------------------------------------------------- // get_current_task - //------------------------------------------------- int abc1600_mac_device::get_current_task(offs_t offset) { int force_task0 = !(m_ifc2 || A19); int t0 = !(BIT(m_task, 0) || force_task0); int t1 = !(BIT(m_task, 1) || force_task0); int t2 = !(BIT(m_task, 2) || force_task0); int t3 = !(BIT(m_task, 3) || force_task0); return (t3 << 3) | (t2 << 2) | (t1 << 1) | t0; } //------------------------------------------------- // get_segment_address - //------------------------------------------------- offs_t abc1600_mac_device::get_segment_address(offs_t offset) { int sega19 = !(!(A8 || m_ifc2) || !A19); int task = get_current_task(offset); return (task << 5) | (sega19 << 4) | ((offset >> 15) & 0x0f); } //------------------------------------------------- // get_page_address - //------------------------------------------------- offs_t abc1600_mac_device::get_page_address(offs_t offset, UINT8 segd) { return ((segd & 0x3f) << 4) | ((offset >> 11) & 0x0f); } //------------------------------------------------- // translate_address - //------------------------------------------------- offs_t abc1600_mac_device::translate_address(offs_t offset, int *nonx, int *wp) { // segment offs_t sega = get_segment_address(offset); UINT8 segd = m_segment_ram[sega]; // page offs_t pga = get_page_address(offset, segd); UINT16 page_data = m_page_ram[pga]; offs_t virtual_offset = ((page_data & 0x3ff) << 11) | (offset & 0x7ff); if (PAGE_NONX) { //logerror("Bus error %06x : %06x\n", offset, virtual_offset); //m_cpu->set_input_line(M68K_LINE_BUSERROR, ASSERT_LINE); //m_cpu->set_input_line(M68K_LINE_BUSERROR, CLEAR_LINE); } *nonx = PAGE_NONX; *wp = PAGE_WP; return virtual_offset; } //------------------------------------------------- // read_user_memory - //------------------------------------------------- UINT8 abc1600_mac_device::read_user_memory(offs_t offset) { int nonx = 0, wp = 0; offs_t virtual_offset = translate_address(offset, &nonx, &wp); return space().read_byte(virtual_offset); } //------------------------------------------------- // write_user_memory - //------------------------------------------------- void abc1600_mac_device::write_user_memory(offs_t offset, UINT8 data) { int nonx = 0, wp = 0; offs_t virtual_offset = translate_address(offset, &nonx, &wp); //if (nonx || !wp) return; space().write_byte(virtual_offset, data); } //------------------------------------------------- // read_supervisor_memory - //------------------------------------------------- UINT8 abc1600_mac_device::read_supervisor_memory(address_space &space, offs_t offset) { UINT8 data = 0; if (!A2 && !A1) { // _EP data = page_r(space, offset); } else if (!A2 && A1 && A0) { // _ES data = segment_r(space, offset); } else if (A2 && A1 && A0) { // _CAUSE data = cause_r(space, offset); } return data; } //------------------------------------------------- // write_supervisor_memory - //------------------------------------------------- void abc1600_mac_device::write_supervisor_memory(address_space &space, offs_t offset, UINT8 data) { if (!A2 && !A1) { // _WEP page_w(space, offset, data); } else if (!A2 && A1 && A0) { // _WES segment_w(space, offset, data); } else if (A2 && !A1 && A0) { // W(C) task_w(space, offset, data); } } //------------------------------------------------- // get_fc - //------------------------------------------------- int abc1600_mac_device::get_fc() { UINT16 fc = m68k_get_fc(m_cpu); m_ifc2 = !(!(MAGIC || FC0) || FC2); return fc; } //------------------------------------------------- // read - //------------------------------------------------- READ8_MEMBER( abc1600_mac_device::read ) { int fc = get_fc(); UINT8 data = 0; if (!BOOTE && !A19 && !A18 && !A17) { // _BOOTCE data = m_rom->base()[offset & 0x3fff]; } else if (A19 && !m_ifc2 && !FC1) { data = read_supervisor_memory(space, offset); } else { data = read_user_memory(offset); } return data; } //------------------------------------------------- // write - //------------------------------------------------- WRITE8_MEMBER( abc1600_mac_device::write ) { int fc = get_fc(); if (A19 && !m_ifc2 && !FC1) { write_supervisor_memory(space, offset, data); } else { write_user_memory(offset, data); } } //------------------------------------------------- // cause_r - //------------------------------------------------- READ8_MEMBER( abc1600_mac_device::cause_r ) { /* bit description 0 RSTBUT 1 1 2 DMAOK 3 X16 4 X17 5 X18 6 X19 7 X20 */ UINT8 data = 0x02; // DMA status data |= m_cause; machine().watchdog_reset(); return data; } //------------------------------------------------- // task_w - //------------------------------------------------- WRITE8_MEMBER( abc1600_mac_device::task_w ) { /* bit description 0 TASKD0* (inverted SEGA5) 1 TASKD1* (inverted SEGA6) 2 TASKD2* (inverted SEGA7) 3 TASKD3* (inverted SEGA8) 4 5 6 BOOTE* 7 MAGIC* */ m_task = data ^ 0xff; if (LOG) logerror("%s: %06x Task %u BOOTE %u MAGIC %u\n", machine().describe_context(), offset, get_current_task(offset), BOOTE, MAGIC); } //------------------------------------------------- // segment_r - //------------------------------------------------- READ8_MEMBER( abc1600_mac_device::segment_r ) { /* bit description 0 SEGD0 1 SEGD1 2 SEGD2 3 SEGD3 4 SEGD4 5 SEGD5 6 SEGD6 7 READ_MAGIC */ offs_t sega = get_segment_address(offset); UINT8 segd = m_segment_ram[sega]; return (READ_MAGIC << 7) | (segd & 0x7f); } //------------------------------------------------- // segment_w - //------------------------------------------------- WRITE8_MEMBER( abc1600_mac_device::segment_w ) { /* bit description 0 SEGD0 1 SEGD1 2 SEGD2 3 SEGD3 4 SEGD4 5 SEGD5 6 SEGD6 7 0 */ offs_t sega = get_segment_address(offset); m_segment_ram[sega] = data & 0x7f; if (LOG) logerror("%s: %06x Task %u Segment %03x : %02x\n", machine().describe_context(), offset, get_current_task(offset), sega, data); } //------------------------------------------------- // page_r - //------------------------------------------------- READ8_MEMBER( abc1600_mac_device::page_r ) { /* bit description 0 X11 1 X12 2 X13 3 X14 4 X15 5 X16 6 X17 7 X18 8 X19 9 X20 10 X20 11 X20 12 X20 13 X20 14 _WP 15 NONX */ // segment offs_t sega = get_segment_address(offset); UINT8 segd = m_segment_ram[sega]; // page offs_t pga = get_page_address(offset, segd); UINT16 pgd = m_page_ram[pga]; UINT8 data = 0; if (A0) { data = pgd & 0xff; } else { int x20 = BIT(pgd, 9); data = (pgd >> 8) | (x20 << 2) | (x20 << 3) | (x20 << 4) | (x20 << 5); } return data; } //------------------------------------------------- // page_w - //------------------------------------------------- WRITE8_MEMBER( abc1600_mac_device::page_w ) { /* bit description 0 X11 1 X12 2 X13 3 X14 4 X15 5 X16 6 X17 7 X18 8 X19 9 X20 10 11 12 13 14 _WP 15 NONX */ // segment offs_t sega = get_segment_address(offset); UINT8 segd = m_segment_ram[sega]; // page offs_t pga = get_page_address(offset, segd); if (A0) { m_page_ram[pga] = (m_page_ram[pga] & 0xff00) | data; } else { m_page_ram[pga] = ((data & 0xc3) << 8) | (m_page_ram[pga] & 0xff); } if (LOG) logerror("%s: %06x Task %u Segment %03x Page %03x : %02x -> %04x\n", machine().describe_context(), offset, get_current_task(offset), sega, pga, data, m_page_ram[pga]); } //------------------------------------------------- // get_dma_address - //------------------------------------------------- offs_t abc1600_mac_device::get_dma_address(int index, UINT16 offset) { // A0 = DMA15, A1 = BA1, A2 = BA2 UINT8 dmamap_addr = index | BIT(offset, 15); UINT8 dmamap = m_dmamap[dmamap_addr]; m_cause = (dmamap & 0x1f) << 3; return ((dmamap & 0x1f) << 16) | offset; } //------------------------------------------------- // dma_mreq_r - DMA memory read //------------------------------------------------- UINT8 abc1600_mac_device::dma_mreq_r(int index, UINT16 offset) { offs_t virtual_offset = get_dma_address(index, offset); return space().read_byte(virtual_offset); } //------------------------------------------------- // dma_mreq_w - DMA memory write //------------------------------------------------- void abc1600_mac_device::dma_mreq_w(int index, UINT16 offset, UINT8 data) { offs_t virtual_offset = get_dma_address(index, offset); space().write_byte(virtual_offset, data); } //------------------------------------------------- // dma_iorq_r - DMA I/O read //------------------------------------------------- UINT8 abc1600_mac_device::dma_iorq_r(int index, UINT16 offset) { offs_t virtual_offset = 0x1fe000 | get_dma_address(index, offset); return space().read_byte(virtual_offset); } //------------------------------------------------- // dma_iorq_w - DMA I/O write //------------------------------------------------- void abc1600_mac_device::dma_iorq_w(int index, UINT16 offset, UINT8 data) { offs_t virtual_offset = 0x1fe000 | get_dma_address(index, offset); space().write_byte(virtual_offset, data); } //------------------------------------------------- // dmamap_w - DMA map write //------------------------------------------------- WRITE8_MEMBER( abc1600_mac_device::dmamap_w ) { /* bit description 0 X16 1 X17 2 X18 3 X19 4 X20 5 6 7 _R/W */ if (LOG) logerror("DMAMAP %u %02x\n", offset & 7, data); m_dmamap[offset & 7] = data; }