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-rw-r--r--src/devices/bus/bbc/internal/ramamp.cpp155
1 files changed, 155 insertions, 0 deletions
diff --git a/src/devices/bus/bbc/internal/ramamp.cpp b/src/devices/bus/bbc/internal/ramamp.cpp
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+++ b/src/devices/bus/bbc/internal/ramamp.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Nigel Barnes
+/**********************************************************************
+
+ Ramamp Computers Sideways RAM/ROM Board
+
+ http://chrisacorns.computinghistory.org.uk/8bit_Upgrades/RAMAMP_SidewaysRAMROM.html
+
+**********************************************************************/
+
+
+#include "emu.h"
+#include "ramamp.h"
+
+
+//**************************************************************************
+// DEVICE DEFINITIONS
+//**************************************************************************
+
+DEFINE_DEVICE_TYPE(BBC_RAMAMP, bbc_ramamp_device, "bbc_ramamp", "Ramamp Sideways RAM/ROM Board");
+
+
+//-------------------------------------------------
+// INPUT_PORTS( ramamp )
+//-------------------------------------------------
+
+static INPUT_PORTS_START(ramamp)
+ 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_ramamp_device::device_input_ports() const
+{
+ return INPUT_PORTS_NAME(ramamp);
+}
+
+//-------------------------------------------------
+// device_add_mconfig - add device configuration
+//-------------------------------------------------
+
+void bbc_ramamp_device::device_add_mconfig(machine_config &config)
+{
+ /* 6 rom sockets, 32K dynamic ram */
+ 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, "ram").set_fixed_ram(true);
+ BBC_ROMSLOT16(config, m_rom[11], bbc_rom_devices, nullptr);
+ BBC_ROMSLOT16(config, m_rom[12], bbc_rom_devices, nullptr);
+ BBC_ROMSLOT16(config, m_rom[13], bbc_rom_devices, "ram").set_fixed_ram(true);
+ BBC_ROMSLOT16(config, m_rom[14], bbc_rom_devices, nullptr);
+ BBC_ROMSLOT16(config, m_rom[15], bbc_rom_devices, nullptr);
+}
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// bbc_ramamp_device - constructor
+//-------------------------------------------------
+
+bbc_ramamp_device::bbc_ramamp_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+ : device_t(mconfig, BBC_RAMAMP, 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_ramamp_device::device_start()
+{
+ /* move internal roms to board */
+ memmove(m_region_swr->base() + 0x2c000, m_region_swr->base(), 0x8000);
+ memmove(m_region_swr->base() + 0x38000, m_region_swr->base() + 0x8000, 0x8000);
+ memset(m_region_swr->base(), 0xff, 0x10000);
+
+ /* register for save states */
+ save_item(NAME(m_romsel));
+}
+
+
+//**************************************************************************
+// IMPLEMENTATION
+//**************************************************************************
+
+uint8_t bbc_ramamp_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;
+ default:
+ /* expansion board 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;
+ }
+
+ return data;
+}
+
+void bbc_ramamp_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 10: case 13:
+ /* expansion board sockets */
+ if (m_rom[m_romsel] && !m_wp->read())
+ {
+ m_rom[m_romsel]->write(offset, data);
+ }
+ break;
+ default:
+ /* expansion board sockets */
+ if (m_rom[m_romsel])
+ {
+ m_rom[m_romsel]->write(offset, data);
+ }
+ break;
+ }
+}