diff options
Diffstat (limited to 'src/devices/bus/a2bus/q68.cpp')
-rw-r--r-- | src/devices/bus/a2bus/q68.cpp | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/src/devices/bus/a2bus/q68.cpp b/src/devices/bus/a2bus/q68.cpp new file mode 100644 index 00000000000..4729f450e4a --- /dev/null +++ b/src/devices/bus/a2bus/q68.cpp @@ -0,0 +1,247 @@ +// license:BSD-3-Clause +// copyright-holders:Rob Justice, R. Belmont +/********************************************************************* + + q68.cpp + + Implementation of the Stellation Q-68 68008 card + + Memory Map + 68008 0x00000-0x0ffff -> Apple II memory + 68008 0x10000-0x17fff -> Onboard EPROM, 8k (expandable to 32k) + 68008 0x18000-0x1ffff -> Onboard RAM, 8K (expandable to 32k?) + 68008 0x20000-0xfffff -> Open, for options via expansion connector + + Apple II Memory + 68008 0x00000-0x003ff -> 6502 0x0800-0x0bff + 68008 0x00400-0x007ff -> 6502 0x0400-0x07ff + 68008 0x00800-0x00bff -> 6502 0x0000-0x03ff + 68008 0x00c00-0x0ffff -> 6502 0x0c00-0xffff + + 0xc0n1 - Turn card on + 0xc0n3 - Interrupt card + 0xc0n0 - Turn card off + + Also includes the Q-68 plus version made by nanja.info + This has a full 1MB of ram on board and slight update to the memory map + Memory Map + 68008 0x00000-0x0ffff -> Apple II memory + 68008 0x10000-0x11fff -> Onboard EPROM, 8k + 68008 0x12000-0x1ffff -> Onboard RAM, ~1MB + + Todo: + Implement Watchdog timer. Only relevant to Q-68 and bus errors for nonexistent memory access + Speed of 6502 should be slower when 68008 is enabled and accessing AppleII memory space + Speed of 68008 should be slower when access the Apple II memory space + + (reference: http://mirrors.apple2.org.za/ftp.apple.asimov.net/unsorted/QPAK-68%20Users%20Guide.pdf ) + +*********************************************************************/ + +#include "emu.h" +#include "q68.h" + +#include "cpu/m68000/m68008.h" + + +/*************************************************************************** + PARAMETERS +***************************************************************************/ + +//************************************************************************** +// GLOBAL VARIABLES +//************************************************************************** + +DEFINE_DEVICE_TYPE(A2BUS_Q68, a2bus_q68_device, "a2q68", "Stellation Two Q-68") +DEFINE_DEVICE_TYPE(A2BUS_Q68PLUS, a2bus_q68plus_device, "a2q68plus", "Stellation Two Q-68 Plus") + +void a2bus_q68_device::m68008_mem(address_map &map) +{ + map(0x00000, 0x0ffff).rw(FUNC(a2bus_q68_device::dma_r), FUNC(a2bus_q68_device::dma_w)); + map(0x10000, 0x11fff).mirror(0x6000).rom(); // 8k debug rom + map(0x18000, 0x19fff).mirror(0x6000).ram(); // 8k of ram +} + +void a2bus_q68plus_device::m68008_mem(address_map &map) +{ + map(0x00000, 0x0ffff).rw(FUNC(a2bus_q68plus_device::dma_r), FUNC(a2bus_q68plus_device::dma_w)); + map(0x10000, 0x11fff).rom(); // 8k debug rom + map(0x12000, 0xfffff).ram(); // 1 MB of RAM +} + +ROM_START( q68 ) + ROM_REGION(0x100000, "m68008", 0) + ROM_LOAD( "debug1.04-caf4.bin", 0x10000, 0x02000, CRC(6bead126) SHA1(e46d5e8256faece3723e9040f78fd1c8edb3ee0e) ) +ROM_END + +/*************************************************************************** + FUNCTION PROTOTYPES +***************************************************************************/ + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void a2bus_q68_device::device_add_mconfig(machine_config &config) +{ + M68008(config, m_m68008, 1021800*7); // M68008 runs at 7.16 MHz + m_m68008->set_addrmap(AS_PROGRAM, &a2bus_q68_device::m68008_mem); +} + +void a2bus_q68plus_device::device_add_mconfig(machine_config &config) +{ + M68008(config, m_m68008, 1021800*7); // M68008 runs at 7.16 MHz + m_m68008->set_addrmap(AS_PROGRAM, &a2bus_q68plus_device::m68008_mem); +} + +//------------------------------------------------- +// device_rom_region - device-specific ROMs +//------------------------------------------------- + +const tiny_rom_entry *a2bus_68k_device::device_rom_region() const +{ + return ROM_NAME( q68 ); +} + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +a2bus_68k_device::a2bus_68k_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_m68008(*this, "m68008") + , m_bEnabled(false) +{ +} + +a2bus_q68_device::a2bus_q68_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : + a2bus_68k_device(mconfig, A2BUS_Q68, tag, owner, clock) +{ +} + +a2bus_q68plus_device::a2bus_q68plus_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : + a2bus_68k_device(mconfig, A2BUS_Q68PLUS, tag, owner, clock) +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void a2bus_68k_device::device_start() +{ + save_item(NAME(m_bEnabled)); +} + +void a2bus_68k_device::device_reset() +{ + m_m68008->set_input_line(INPUT_LINE_RESET, ASSERT_LINE); + m_m68008->set_input_line(INPUT_LINE_HALT, ASSERT_LINE); + m_bEnabled=false; +} + +uint8_t a2bus_68k_device::read_c0nx(uint8_t offset) +{ + switch (offset & 0x3) + { + case 0: + case 2: + m_m68008->set_input_line(INPUT_LINE_RESET, ASSERT_LINE); + m_m68008->set_input_line(INPUT_LINE_HALT, ASSERT_LINE); + m_bEnabled=false; + break; + + case 1: + m_m68008->set_input_line(INPUT_LINE_RESET, CLEAR_LINE); + m_m68008->set_input_line(INPUT_LINE_HALT, CLEAR_LINE); + m_bEnabled=true; + break; + + case 3: + m_m68008->set_input_line(INPUT_LINE_RESET, CLEAR_LINE); + m_m68008->set_input_line(INPUT_LINE_HALT, CLEAR_LINE); + m_bEnabled=true; + m_m68008->pulse_input_line(M68K_IRQ_7, attotime::zero); //work around, processor status lines + logic should clear nmi. + break; + } + return 0; +} + +void a2bus_68k_device::write_c0nx(uint8_t offset, uint8_t data) +{ + switch (offset & 0x3) + { + case 0: + case 2: + m_m68008->set_input_line(INPUT_LINE_RESET, ASSERT_LINE); + m_m68008->set_input_line(INPUT_LINE_HALT, ASSERT_LINE); + m_bEnabled=false; + break; + + case 1: + m_m68008->set_input_line(INPUT_LINE_RESET, CLEAR_LINE); + m_m68008->set_input_line(INPUT_LINE_HALT, CLEAR_LINE); + m_bEnabled=true; + break; + + case 3: + m_m68008->set_input_line(INPUT_LINE_RESET, CLEAR_LINE); + m_m68008->set_input_line(INPUT_LINE_HALT, CLEAR_LINE); + m_bEnabled=true; + m_m68008->pulse_input_line(M68K_IRQ_7, attotime::zero); //work around, processor status lines should clear nmi. + break; + } +} + +uint8_t a2bus_68k_device::dma_r(offs_t offset) +{ + if (m_bEnabled) + { + if (offset <= 0x03ff) //0x0000-0x03ff + { + return slot_dma_read(offset+0x800); + } + else if (offset <= 0x07ff) //0x0400-0x07ff + { + return slot_dma_read(offset); + } + else if (offset <= 0x0bff) //0x0800-0x0bff + { + return slot_dma_read(offset-0x800); + } + else if (offset <= 0xffff) //0x0c00-0xffff + { + return slot_dma_read(offset); + } + } + return 0xff; +} + + +//------------------------------------------------- +// dma_w - +//------------------------------------------------- + +void a2bus_68k_device::dma_w(offs_t offset, uint8_t data) +{ + if (m_bEnabled) + { + if (offset <= 0x03ff) //0x0000-0x03ff + { + return slot_dma_write(offset+0x800, data); + } + else if (offset <= 0x07ff) //0x0400-0x07ff + { + return slot_dma_write(offset, data); + } + else if (offset <= 0x0bff) //0x0800-0x0bff + { + return slot_dma_write(offset-0x800, data); + } + else if (offset <= 0xffff) //0x0c00-0xffff + { + return slot_dma_write(offset, data); + } + } +} |