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-rw-r--r--src/devices/bus/a2bus/a2lang.cpp145
1 files changed, 145 insertions, 0 deletions
diff --git a/src/devices/bus/a2bus/a2lang.cpp b/src/devices/bus/a2bus/a2lang.cpp
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index 00000000000..9a0b21dca36
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+++ b/src/devices/bus/a2bus/a2lang.cpp
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+// license:BSD-3-Clause
+// copyright-holders:R. Belmont
+/*********************************************************************
+
+ a2lang.c
+
+ Implementation of the Apple II Language Card
+
+ TODO: refactor machine/apple2.c so it's possible to have an Apple II
+ and II Plus without a language card (and to emulate other
+ slot 0 stuff like hack/freezer cards).
+
+*********************************************************************/
+
+#include "emu.h"
+#include "includes/apple2.h"
+#include "a2lang.h"
+
+
+/***************************************************************************
+ PARAMETERS
+***************************************************************************/
+
+#define LOG_LANGCARD 0
+
+//**************************************************************************
+// GLOBAL VARIABLES
+//**************************************************************************
+
+const device_type A2BUS_LANG = &device_creator<a2bus_lang_device>;
+
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+a2bus_lang_device::a2bus_lang_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+ device_t(mconfig, A2BUS_LANG, "Apple II Language Card", tag, owner, clock, "a2lang", __FILE__),
+ device_a2bus_card_interface(mconfig, *this)
+{
+ last_offset = -1;
+}
+
+a2bus_lang_device::a2bus_lang_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source) :
+ device_t(mconfig, type, name, tag, owner, clock, shortname, source),
+ device_a2bus_card_interface(mconfig, *this)
+{
+ last_offset = -1;
+}
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void a2bus_lang_device::device_start()
+{
+ // set_a2bus_device makes m_slot valid
+ set_a2bus_device();
+
+ save_item(NAME(last_offset));
+}
+
+void a2bus_lang_device::device_reset()
+{
+}
+
+/*-------------------------------------------------
+ apple2_langcard_touch - device read callback
+-------------------------------------------------*/
+
+void a2bus_lang_device::langcard_touch(offs_t offset)
+{
+ UINT32 val, mask;
+
+ if (LOG_LANGCARD)
+ logerror("language card bankswitch read, offset: $c08%0x\n", offset);
+
+ /* determine which flags to change */
+ mask = VAR_LCWRITE | VAR_LCRAM | VAR_LCRAM2;
+ val = 0;
+
+ if (offset & 0x01)
+ val |= VAR_LCWRITE;
+
+ switch(offset & 0x03)
+ {
+ case 0x03:
+ case 0x00:
+ val |= VAR_LCRAM;
+ break;
+ }
+
+ if ((offset & 0x08) == 0)
+ val |= VAR_LCRAM2;
+
+ /* change the flags */
+ apple2_state *state = machine().driver_data<apple2_state>();
+ state->apple2_setvar(val, mask);
+}
+
+
+
+/*-------------------------------------------------
+ read_c0nx - called for reads from this card's c0nx space
+-------------------------------------------------*/
+
+UINT8 a2bus_lang_device::read_c0nx(address_space &space, UINT8 offset)
+{
+ apple2_state *state = machine().driver_data<apple2_state>();
+
+ // enforce "read twice" for c081/3/9/B
+ // but only on the II/II+ with a discrete language card.
+ // later machines' ASICs dropped the double-read requirement,
+ // likely to be interrupt-safe.
+ if (state->m_machinetype == APPLE_II)
+ {
+ switch (offset & 0x03)
+ {
+ case 1:
+ case 3:
+ if (offset != last_offset)
+ {
+ last_offset = offset;
+ return 0;
+ }
+ break;
+ }
+ }
+
+ langcard_touch(offset);
+ last_offset = offset;
+ return 0;
+}
+
+
+
+/*-------------------------------------------------
+ write_c0nx - called for writes to this card's c0nx space
+-------------------------------------------------*/
+
+void a2bus_lang_device::write_c0nx(address_space &space, UINT8 offset, UINT8 data)
+{
+ langcard_touch(offset);
+ last_offset = -1;
+}