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Diffstat (limited to 'src/devices/bus/pc8801/pcg8100.cpp')
-rw-r--r--src/devices/bus/pc8801/pcg8100.cpp109
1 files changed, 109 insertions, 0 deletions
diff --git a/src/devices/bus/pc8801/pcg8100.cpp b/src/devices/bus/pc8801/pcg8100.cpp
new file mode 100644
index 00000000000..c2bf07c7f73
--- /dev/null
+++ b/src/devices/bus/pc8801/pcg8100.cpp
@@ -0,0 +1,109 @@
+// license:BSD-3-Clause
+// copyright-holders:Angelo Salese
+/**************************************************************************************************
+
+ HAL PCG-8100
+
+ Used on a bunch of PC-8001 games, adds a Programmable Character Generator overlay,
+ a write-only 8253 with channels tied to three DAC1BIT
+
+**************************************************************************************************/
+
+#include "emu.h"
+#include "pcg8100.h"
+
+
+DEFINE_DEVICE_TYPE(PCG8100, pcg8100_device, "pcg8100", "HAL Laboratory PCG-8100")
+
+pcg8100_device::pcg8100_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+ : pc8801_exp_device(mconfig, PCG8100, tag, owner, clock)
+ , m_pit(*this, "pit")
+ , m_dac1bit(*this, "dac1bit%u", 0L)
+ , m_cg_rom(*this, "^^cgrom")
+{
+}
+
+void pcg8100_device::io_map(address_map &map)
+{
+ map(0x00, 0x00).lw8(NAME([this] (u8 data) { m_pcg_data = data; }));
+ map(0x01, 0x01).lw8(NAME([this] (u8 data) { m_pcg_address = (m_pcg_address & 0x300) | data; }));
+ map(0x02, 0x02).w(FUNC(pcg8100_device::pcg_latch_w));
+ map(0x0c, 0x0f).w(m_pit, FUNC(pit8253_device::write));
+}
+
+void pcg8100_device::device_add_mconfig(machine_config &config)
+{
+ constexpr XTAL pcg_clock = XTAL(31'948'800) / 8;
+
+ PIT8253(config, m_pit, 0);
+ m_pit->set_clk<0>(pcg_clock);
+ m_pit->out_handler<0>().set(m_dac1bit[0], FUNC(speaker_sound_device::level_w));
+ m_pit->set_clk<1>(pcg_clock);
+ m_pit->out_handler<1>().set(m_dac1bit[1], FUNC(speaker_sound_device::level_w));
+ m_pit->set_clk<2>(pcg_clock);
+ m_pit->out_handler<2>().set(m_dac1bit[2], FUNC(speaker_sound_device::level_w));
+
+ for (auto &dac1bit : m_dac1bit)
+ {
+ SPEAKER_SOUND(config, dac1bit);
+ dac1bit->add_route(ALL_OUTPUTS, "^^lspeaker", 0.25);
+ dac1bit->add_route(ALL_OUTPUTS, "^^rspeaker", 0.25);
+ }
+}
+
+void pcg8100_device::device_start()
+{
+ save_item(NAME(m_pcg_data));
+ save_item(NAME(m_pcg_address));
+
+ // PCG overlays directly to the internal PC-8001 3301 CG ROM base.
+ // Save a local copy of the original data here, card can eventually restore data at later time.
+ for (int i = 0x000; i < 0x400; i++)
+ m_original_rom[i] = m_cg_rom[i | 0x400];
+
+ save_item(NAME(m_original_rom));
+}
+
+void pcg8100_device::device_reset()
+{
+ int i;
+ m_pcg_data = 0;
+ m_pcg_address = 0;
+ m_pcg_latch = 0;
+
+ for (i = 0x000; i < 0x400; i++)
+ m_cg_rom[i | 0x400] = m_original_rom[i];
+
+ for (i = 0; i < 3; i++)
+ audio_channel(i, false);
+}
+
+void pcg8100_device::audio_channel(u8 ch, bool keyon)
+{
+ m_dac1bit[ch]->set_output_gain(0, keyon ? 1.0 : 0.0);
+}
+
+/*
+ * x--- ---- DAC1BIT #2
+ * -x-- ---- DAC1BIT #1
+ * --x- ---- (0) select overlay on latch (1) select PC-8001/PC-8801 original CG ROM
+ * ---x ---- latch data into current PCG address RAM
+ * ---- x--- DAC1BIT #0
+ * ---- --xx upper PCG address
+ */
+void pcg8100_device::pcg_latch_w(u8 data)
+{
+ if (BIT(m_pcg_latch, 4) && !(BIT(data, 4)))
+ {
+ if (BIT(m_pcg_latch, 5))
+ m_cg_rom[0x400 | m_pcg_address] = m_original_rom[m_pcg_address];
+ else
+ m_cg_rom[0x400 | m_pcg_address] = m_pcg_data;
+ }
+ m_pcg_address = (m_pcg_address & 0xff) | ((data & 0x3) << 8);
+ m_pcg_latch = data;
+
+ audio_channel(0, bool(BIT(data, 3)));
+ audio_channel(1, bool(BIT(data, 6)));
+ audio_channel(2, bool(BIT(data, 7)));
+}