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// license:BSD-3-Clause
// copyright-holders:Nigel Barnes
/**********************************************************************
Solidisk Twomeg 128K Shadow and Sideways ROM/RAM board
**********************************************************************/
#include "emu.h"
#include "stl2m128.h"
//**************************************************************************
// DEVICE DEFINITIONS
//**************************************************************************
DEFINE_DEVICE_TYPE(BBC_STL2M128, bbc_stl2m128_device, "bbc_stl2m128", "Solidisk Twomeg 128K RAM/ROM Expansion");
//-------------------------------------------------
// INPUT_PORTS( stl2m128 )
//-------------------------------------------------
static INPUT_PORTS_START(stl2m128)
PORT_START("wp")
PORT_CONFNAME(0x01, 0x00, "Write Protect Sideways RAM")
PORT_CONFSETTING(0x00, DEF_STR(No))
PORT_CONFSETTING(0x01, DEF_STR(Yes))
INPUT_PORTS_END
//-------------------------------------------------
// input_ports - device-specific input ports
//-------------------------------------------------
ioport_constructor bbc_stl2m128_device::device_input_ports() const
{
return INPUT_PORTS_NAME(stl2m128);
}
//-------------------------------------------------
// ROM( stl2m128 )
//-------------------------------------------------
ROM_START(stl2m128)
ROM_REGION(0x4000, "rom", ROMREGION_ERASEFF)
// ROM image usually distributed on floppy, to load into RAM
ROM_LOAD("manger128-1.00.rom", 0x0000, 0x102a, CRC(dbe84acb) SHA1(d170632b88d0ab276a919b0076dca305094a39b2))
ROM_END
//-------------------------------------------------
// device_add_mconfig - add device configuration
//-------------------------------------------------
void bbc_stl2m128_device::device_add_mconfig(machine_config &config)
{
BBC_ROMSLOT16(config, m_rom[4], bbc_rom_devices, "ram").set_fixed_ram(true);
BBC_ROMSLOT16(config, m_rom[5], bbc_rom_devices, "ram").set_fixed_ram(true);
BBC_ROMSLOT16(config, m_rom[6], bbc_rom_devices, "ram").set_fixed_ram(true);
BBC_ROMSLOT16(config, m_rom[7], bbc_rom_devices, "ram").set_fixed_ram(true);
BBC_ROMSLOT16(config, m_rom[8], bbc_rom_devices, nullptr);
BBC_ROMSLOT16(config, m_rom[9], bbc_rom_devices, nullptr);
BBC_ROMSLOT16(config, m_rom[10], bbc_rom_devices, nullptr);
BBC_ROMSLOT16(config, m_rom[11], bbc_rom_devices, nullptr);
BBC_ROMSLOT16(config, m_rom[12], bbc_rom_devices, "ram").set_fixed_ram(true);
BBC_ROMSLOT16(config, m_rom[13], bbc_rom_devices, "ram").set_fixed_ram(true);
BBC_ROMSLOT16(config, m_rom[14], bbc_rom_devices, "ram").set_fixed_ram(true);
BBC_ROMSLOT16(config, m_rom[15], bbc_rom_devices, "ram").set_fixed_ram(true);
}
//-------------------------------------------------
// rom_region - device-specific ROM region
//-------------------------------------------------
const tiny_rom_entry *bbc_stl2m128_device::device_rom_region() const
{
return ROM_NAME(stl2m128);
}
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// bbc_stl2m128_device - constructor
//-------------------------------------------------
bbc_stl2m128_device::bbc_stl2m128_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, BBC_STL2M128, tag, owner, clock)
, device_bbc_internal_interface(mconfig, *this)
, m_rom(*this, "romslot%u", 0U)
, m_wp(*this, "wp")
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void bbc_stl2m128_device::device_start()
{
m_ram = std::make_unique<uint8_t[]>(0x20000);
/* copy rom image into ram bank c */
memcpy(&m_ram[0x10000], memregion("rom")->base(), 0x4000);
/* move internal roms to board */
memmove(m_region_swr->base() + 0x20000, m_region_swr->base(), 0x10000);
memset(m_region_swr->base(), 0xff, 0x10000);
/* register for save states */
save_pointer(NAME(m_ram), 0x20000);
save_item(NAME(m_romsel));
save_item(NAME(m_shadow));
}
//**************************************************************************
// IMPLEMENTATION
//**************************************************************************
void bbc_stl2m128_device::romsel_w(offs_t offset, uint8_t data)
{
switch (offset & 0x0c)
{
case 0x00:
m_romsel = data & 0x0f;
break;
case 0x04:
m_shadow = data;
break;
}
}
uint8_t bbc_stl2m128_device::ram_r(offs_t offset)
{
uint8_t data = 0xff;
if (BIT(m_shadow, 7) && offset >= 0x2000)
{
if (BIT(m_shadow, 1))
{
/* banks E/F */
data = m_ram[offset | 0x18000];
}
else
{
/* banks C/D */
data = m_ram[offset | 0x10000];
}
}
else
{
data = m_mb_ram->pointer()[offset];
}
return data;
}
void bbc_stl2m128_device::ram_w(offs_t offset, uint8_t data)
{
if (BIT(m_shadow, 7) && offset >= 0x2000)
{
if (BIT(m_shadow, 1))
{
/* banks E/F */
m_ram[offset | 0x18000] = data;
}
else
{
/* banks C/D */
m_ram[offset | 0x10000] = data;
}
}
else
{
m_mb_ram->pointer()[offset] = data;
}
}
uint8_t bbc_stl2m128_device::paged_r(offs_t offset)
{
uint8_t data = 0xff;
switch (m_romsel)
{
case 0: case 1: case 2: case 3:
/* motherboard rom sockets */
if (m_mb_rom[m_romsel] && m_mb_rom[m_romsel]->present())
{
data = m_mb_rom[m_romsel]->read(offset);
}
else
{
data = m_region_swr->base()[offset + (m_romsel << 14)];
}
break;
case 8: case 9: case 10: case 11:
/* expansion board rom sockets */
if (m_rom[m_romsel] && m_rom[m_romsel]->present())
{
data = m_rom[m_romsel]->read(offset);
}
else
{
data = m_region_swr->base()[offset + (m_romsel << 14)];
}
break;
case 4: case 5: case 6: case 7: case 12: case 13: case 14: case 15:
/* expansion board ram sockets */
data = m_ram[offset | ((m_romsel & 0x03) << 14) | ((m_romsel & 0x08) << 13)];
break;
}
return data;
}
void bbc_stl2m128_device::paged_w(offs_t offset, uint8_t data)
{
switch (m_romsel)
{
case 0: case 1: case 2: case 3:
/* motherboard rom sockets */
if (m_mb_rom[m_romsel])
{
m_mb_rom[m_romsel]->write(offset, data);
}
break;
case 8: case 9: case 10: case 11:
/* expansion board rom sockets */
if (m_rom[m_romsel])
{
m_rom[m_romsel]->write(offset, data);
}
break;
case 4: case 5: case 6: case 7: case 12: case 13: case 14: case 15:
/* expansion board ram sockets */
if (!m_wp->read())
{
m_ram[offset | ((m_romsel & 0x03) << 14) | ((m_romsel & 0x08) << 13)] = data;
}
break;
}
}
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