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-rw-r--r--src/devices/bus/c64/multiscreen.cpp226
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diff --git a/src/devices/bus/c64/multiscreen.cpp b/src/devices/bus/c64/multiscreen.cpp
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+++ b/src/devices/bus/c64/multiscreen.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Curt Coder
+/**********************************************************************
+
+ Multiscreen cartridge emulation
+
+**********************************************************************/
+
+/*
+
+ PCB Layout
+ ----------
+
+ |===================|
+ | ROM6 |
+ | MC14066 |
+ | |
+ |===============| ROM5 |
+ |=| |
+ |=| |
+ |=| RAM BAT ROM4 |
+ |=| |
+ |=| |
+ |=| ROM0 ROM3 |
+ |=| |
+ |=| |
+ |===============| LS138 ROM2 |
+ | LS138 |
+ | LS174 |
+ | LS133 ROM1 |
+ |===================|
+
+ BAT - BR2325 lithium battery
+ RAM - ? 8Kx8 RAM
+ ROM0 - ? 16Kx8 EPROM
+ ROM1 - ? 32Kx8 EPROM
+ ROM2 - ? 32Kx8 EPROM
+ ROM3 - ? 32Kx8 EPROM
+ ROM4 - not populated
+ ROM5 - not populated
+ ROM6 - not populated
+
+*/
+
+/*
+
+ TODO:
+
+ - M6802 board
+ - crashes on boot
+
+ 805A: lda $01
+ 805C: and #$FE
+ 805E: sta $01
+ 8060: m6502_brk#$00 <-- BOOM!
+
+*/
+
+#include "multiscreen.h"
+
+
+
+//**************************************************************************
+// MACROS/CONSTANTS
+//**************************************************************************
+
+#define MC6802P_TAG "m6802"
+#define MC6821P_0_TAG "m6821_0"
+#define MC6821P_1_TAG "m6821_1"
+
+
+#define BANK_RAM 0x0d
+
+
+
+//**************************************************************************
+// DEVICE DEFINITIONS
+//**************************************************************************
+
+const device_type C64_MULTISCREEN = &device_creator<c64_multiscreen_cartridge_device>;
+
+
+//-------------------------------------------------
+// ROM( c64_multiscreen )
+//-------------------------------------------------
+
+ROM_START( c64_multiscreen )
+ ROM_REGION( 0x2000, MC6802P_TAG, 0 )
+ ROM_LOAD( "1", 0x0000, 0x1000, CRC(35be02a8) SHA1(5912bc3d8e0c0949c1e66c19116d6b71c7574e46) )
+ ROM_LOAD( "2 cr", 0x1000, 0x1000, CRC(76a9ac6d) SHA1(87e7335e626bdb73498b46c28c7baab72df38d1f) )
+ROM_END
+
+
+//-------------------------------------------------
+// rom_region - device-specific ROM region
+//-------------------------------------------------
+
+const rom_entry *c64_multiscreen_cartridge_device::device_rom_region() const
+{
+ return ROM_NAME( c64_multiscreen );
+}
+
+
+static ADDRESS_MAP_START( multiscreen_mem, AS_PROGRAM, 8, c64_multiscreen_cartridge_device )
+ AM_RANGE(0x0000, 0x1fff) AM_ROM AM_REGION(MC6802P_TAG, 0)
+ADDRESS_MAP_END
+
+
+//-------------------------------------------------
+// MACHINE_CONFIG_FRAGMENT( c64_multiscreen )
+//-------------------------------------------------
+
+static MACHINE_CONFIG_FRAGMENT( c64_multiscreen )
+ MCFG_CPU_ADD(MC6802P_TAG, M6802, XTAL_4MHz)
+ MCFG_CPU_PROGRAM_MAP(multiscreen_mem)
+
+ MCFG_DEVICE_ADD(MC6821P_0_TAG, PIA6821, 0)
+ MCFG_DEVICE_ADD(MC6821P_1_TAG, PIA6821, 0)
+MACHINE_CONFIG_END
+
+
+//-------------------------------------------------
+// machine_config_additions - device-specific
+// machine configurations
+//-------------------------------------------------
+
+machine_config_constructor c64_multiscreen_cartridge_device::device_mconfig_additions() const
+{
+ return MACHINE_CONFIG_NAME( c64_multiscreen );
+}
+
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// c64_multiscreen_cartridge_device - constructor
+//-------------------------------------------------
+
+c64_multiscreen_cartridge_device::c64_multiscreen_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+ device_t(mconfig, C64_MULTISCREEN, "C64 Multiscreen cartridge", tag, owner, clock, "c64_mscr", __FILE__),
+ device_c64_expansion_card_interface(mconfig, *this)
+{
+}
+
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void c64_multiscreen_cartridge_device::device_start()
+{
+ // state saving
+ save_item(NAME(m_bank));
+}
+
+
+//-------------------------------------------------
+// device_reset - device-specific reset
+//-------------------------------------------------
+
+void c64_multiscreen_cartridge_device::device_reset()
+{
+ m_bank = 0;
+}
+
+
+//-------------------------------------------------
+// c64_cd_r - cartridge data read
+//-------------------------------------------------
+
+UINT8 c64_multiscreen_cartridge_device::c64_cd_r(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2)
+{
+ if (!roml)
+ {
+ int bank = m_bank & 0x0f;
+
+ if (bank == BANK_RAM)
+ {
+ data = m_nvram[offset & 0x1fff];
+ }
+ else
+ {
+ data = m_roml[(bank << 14) | (offset & 0x3fff)];
+ }
+ }
+ else if (!romh)
+ {
+ int bank = m_bank & 0x0f;
+
+ if (bank == BANK_RAM)
+ {
+ data = m_roml[offset & 0x3fff];
+ }
+ else
+ {
+ data = m_roml[(bank << 14) | (offset & 0x3fff)];
+ }
+ }
+
+ return data;
+}
+
+
+//-------------------------------------------------
+// c64_cd_w - cartridge data write
+//-------------------------------------------------
+
+void c64_multiscreen_cartridge_device::c64_cd_w(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2)
+{
+ if (offset >= 0x8000 && offset < 0xa000)
+ {
+ int bank = m_bank & 0x0f;
+
+ if (bank == BANK_RAM)
+ {
+ m_nvram[offset & 0x1fff] = data;
+ }
+ }
+ else if (!io2)
+ {
+ m_bank = data;
+ }
+}