// license:BSD-3-Clause // copyright-holders:Curt Coder /********************************************************************** SilverRock Productions cartridge emulation Copyright MESS Team. Visit http://mamedev.org for licensing and usage restrictions. **********************************************************************/ /* PCB Layout ---------- e9048 |=============| |=| LS00 | |=| LS273| |=| | |=| | |=| ROM | |=| | |=| | |=| | |=============| ROM - Atmel AT27C010-25PC 128Kx8 OTP EPROM "HUGO 2012" */ #include "silverrock.h" //************************************************************************** // MACROS/CONSTANTS //************************************************************************** #define UNSCRAMBLE_ADDRESS(_offset) \ BITSWAP16(_offset,15,14,13,12,1,0,2,3,11,10,9,8,7,6,5,4) #define UNSCRAMBLE_DATA(_data) \ BITSWAP8(_data,7,6,5,4,0,1,2,3) //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** const device_type C64_SILVERROCK = &device_creator; //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // c64_silverrock_cartridge_device - constructor //------------------------------------------------- c64_silverrock_cartridge_device::c64_silverrock_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : device_t(mconfig, C64_SILVERROCK, "C64 SilverRock cartridge", tag, owner, clock, "c64_silverrock", __FILE__), device_c64_expansion_card_interface(mconfig, *this) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void c64_silverrock_cartridge_device::device_start() { // state saving save_item(NAME(m_bank)); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void c64_silverrock_cartridge_device::device_reset() { m_bank = 0; } //------------------------------------------------- // c64_cd_r - cartridge data read //------------------------------------------------- UINT8 c64_silverrock_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) { offs_t addr = (m_bank << 13) | (offset & 0x1fff); addr = (addr & 0x10000) | UNSCRAMBLE_ADDRESS(addr); data = UNSCRAMBLE_DATA(m_roml[addr]); } return data; } //------------------------------------------------- // c64_cd_w - cartridge data write //------------------------------------------------- void c64_silverrock_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 (!io1) { /* bit description 0 1 2 3 4 A14 5 A15 6 A16 7 A13 */ m_bank = ((data >> 3) & 0x0e) | BIT(data, 7); } }