summaryrefslogtreecommitdiffstatshomepage
path: root/src/devices/bus/a800/sparta.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/devices/bus/a800/sparta.c')
-rw-r--r--src/devices/bus/a800/sparta.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/src/devices/bus/a800/sparta.c b/src/devices/bus/a800/sparta.c
new file mode 100644
index 00000000000..8e6a439d669
--- /dev/null
+++ b/src/devices/bus/a800/sparta.c
@@ -0,0 +1,71 @@
+// license:BSD-3-Clause
+// copyright-holders:Fabio Priuli
+/***********************************************************************************************************
+
+ A800 SpartaDOS cart emulation
+
+***********************************************************************************************************/
+
+
+#include "emu.h"
+#include "sparta.h"
+
+
+//-------------------------------------------------
+// constructor
+//-------------------------------------------------
+
+const device_type A800_ROM_SPARTADOS = &device_creator<a800_rom_spartados_device>;
+
+
+a800_rom_spartados_device::a800_rom_spartados_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : a800_rom_device(mconfig, A800_ROM_SPARTADOS, "Atari 800 SpartaDOS ROM Carts", tag, owner, clock, "a800_sparta", __FILE__)
+{
+}
+
+
+
+void a800_rom_spartados_device::device_start()
+{
+ save_item(NAME(m_bank));
+ save_item(NAME(m_subslot_enabled));
+}
+
+void a800_rom_spartados_device::device_reset()
+{
+ m_bank = 0;
+ m_subslot_enabled = 0;
+}
+
+
+/*-------------------------------------------------
+ mapper specific handlers
+ -------------------------------------------------*/
+
+/*-------------------------------------------------
+
+ SpartaDOS 64K carts
+
+ Similar to Express / Diamond carts, because
+ bankswitch is controlled by writing to 7 diff
+ offsets in reverse order, but writes to offsets
+ 0x8-0xf also enable/disable subslot
+
+ -------------------------------------------------*/
+
+READ8_MEMBER(a800_rom_spartados_device::read_80xx)
+{
+ if (!m_subslot_enabled)
+ return m_rom[(offset & 0x1fff) + (m_bank * 0x2000)];
+ else
+ return 0xff; // subslot, currently not implemented
+}
+
+WRITE8_MEMBER(a800_rom_spartados_device::write_d5xx)
+{
+ if (offset & 0x08)
+ m_subslot_enabled = !BIT(offset, 2);
+ else
+ m_bank = (offset ^ 0x07) & 0x0f;
+
+}