diff options
Diffstat (limited to 'src/devices/bus/bbc/1mhzbus/pms64k.cpp')
-rw-r--r-- | src/devices/bus/bbc/1mhzbus/pms64k.cpp | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/devices/bus/bbc/1mhzbus/pms64k.cpp b/src/devices/bus/bbc/1mhzbus/pms64k.cpp new file mode 100644 index 00000000000..0c975b39f48 --- /dev/null +++ b/src/devices/bus/bbc/1mhzbus/pms64k.cpp @@ -0,0 +1,80 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/********************************************************************** + + PMS 64K Non-Volatile Ram Module + + TODO: + - Find accompanying software, needed to install utilities to RAM. + +**********************************************************************/ + + +#include "emu.h" +#include "pms64k.h" + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE(BBC_PMS64K, bbc_pms64k_device, "bbc_pms64k", "PMS 64K Non-Volatile Ram Module"); + + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void bbc_pms64k_device::device_add_mconfig(machine_config &config) +{ + NVRAM(config, "nvram", nvram_device::DEFAULT_NONE); +} + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// bbc_pms64k_device - constructor +//------------------------------------------------- + +bbc_pms64k_device::bbc_pms64k_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : device_t(mconfig, BBC_PMS64K, tag, owner, clock) + , device_bbc_1mhzbus_interface(mconfig, *this) + , m_nvram(*this, "nvram") + , m_ram_page(0) +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void bbc_pms64k_device::device_start() +{ + m_ram = std::make_unique<uint8_t[]>(0x10000); + m_nvram->set_base(m_ram.get(), 0x10000); +} + + +//************************************************************************** +// IMPLEMENTATION +//************************************************************************** + +void bbc_pms64k_device::fred_w(offs_t offset, uint8_t data) +{ + if (offset == 0xff) + { + m_ram_page = data; + } +} + +uint8_t bbc_pms64k_device::jim_r(offs_t offset) +{ + return m_ram[(m_ram_page << 8) | offset]; +} + +void bbc_pms64k_device::jim_w(offs_t offset, uint8_t data) +{ + m_ram[(m_ram_page << 8) | offset] = data; +} |