(MESS) Alphatronic: Can load the user-supplied tape. Sometimes it can load its own tapes.

src/mess/drivers/alphatro.c

@@ -4,13 +4,18 @@
 
     skeleton driver
 
-    z80 + HD46505 as a CRTC
+    z80 + HD46505SP as a CRTC
+
+    Other chips: 8251, 8257, 8259
+    Crystals: 16MHz, 17.73447MHz
+    Floppy format: 2 sides, 40 tracks, 16 sectors, 256 bytes = 320kb.
+    FDC (unknown) is in a plug-in module.
 
     Has a socket for monochrome (to the standard amber monitor),
     and another for RGB. We emulate this with a configuration switch.
 
     The Z80 must start at E000, but unlike other designs (Super80 for
-        example) which causes the ROMs to appear everywhere during boot,
+    example) which cause the ROMs to appear everywhere during boot,
     this one (it seems) holds the data bus low until E000 is reached.
     This kind of boot still needs to be emulated.
 
@@ -49,7 +54,7 @@ public:
 	m_cass(*this, "cassette"),
 	m_beep(*this, "beeper"),
 	m_p_ram(*this, "p_ram"),
-	m_p_videoram(*this, "p_videoram"){ }
+	m_p_videoram(*this, "videoram"){ }
 
 	required_device<cpu_device> m_maincpu;
 	required_device<mc6845_device> m_crtc;
@@ -62,6 +67,8 @@ public:
 	DECLARE_INPUT_CHANGED_MEMBER(alphatro_break);
 	DECLARE_READ_LINE_MEMBER(rxdata_callback);
 	DECLARE_WRITE_LINE_MEMBER(txdata_callback);
+	TIMER_DEVICE_CALLBACK_MEMBER(alphatro_c);
+	TIMER_DEVICE_CALLBACK_MEMBER(alphatro_p);
 
 	required_shared_ptr<UINT8> m_p_ram;
 	required_shared_ptr<UINT8> m_p_videoram;
@@ -75,6 +82,8 @@ public:
 
 private:
 	UINT8 m_timer_bit;
+	UINT8 m_cass_data[4];
+	bool m_cass_state;
 	virtual void palette_init();
 };
 
@@ -105,6 +114,9 @@ WRITE8_MEMBER( alphatro_state::port10_w )
 	}
 
 	m_cass->change_state( BIT(data, 3) ? CASSETTE_MOTOR_ENABLED : CASSETTE_MOTOR_DISABLED, CASSETTE_MASK_MOTOR);
+
+	if (BIT(data,2))
+		m_cass_state = 1;
 }
 
 void alphatro_state::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr)
@@ -128,12 +140,12 @@ void alphatro_state::device_timer(emu_timer &timer, device_timer_id id, int para
 
 READ_LINE_MEMBER( alphatro_state::rxdata_callback )
 {
-	return (m_cass->input() > -0.1) ? 1 : 0;
+	return (bool)m_cass_data[2];
 }
 
 WRITE_LINE_MEMBER( alphatro_state::txdata_callback )
 {
-	m_cass->output( (state) ? 0.8 : -0.8);
+	m_cass_state = state;
 }
 
 void alphatro_state::video_start()
@@ -186,7 +198,7 @@ INPUT_CHANGED_MEMBER( alphatro_state::alphatro_break )
 
 static ADDRESS_MAP_START( alphatro_map, AS_PROGRAM, 8, alphatro_state )
 	AM_RANGE(0x0000, 0xefff) AM_RAM AM_SHARE("p_ram")
-	AM_RANGE(0xf000, 0xffff) AM_RAM AM_SHARE("p_videoram")
+	AM_RANGE(0xf000, 0xffff) AM_RAM AM_SHARE("videoram")
 ADDRESS_MAP_END
 
 static ADDRESS_MAP_START( alphatro_io, AS_IO, 8, alphatro_state )
@@ -353,17 +365,20 @@ void alphatro_state::machine_start()
 void alphatro_state::machine_reset()
 {
 	// do what the IPL does
-	//  UINT8* RAM = machine().device<ram_device>("ram")->pointer();
 	UINT8* ROM = memregion("maincpu")->base();
 	m_maincpu->set_pc(0xe000);
 	memcpy(m_p_ram, ROM, 0xf000); // copy BASIC to RAM, which the undumped IPL is supposed to do.
 	memcpy(m_p_videoram, ROM+0x1000, 0x1000);
-	//  membank("bank1")->set_base(RAM);
 
 	// probably not correct, exact meaning of port is unknown, vblank/vsync is too slow.
 	m_sys_timer->adjust(attotime::from_usec(10),0,attotime::from_usec(10));
-	m_serial_timer->adjust(attotime::from_hz(500),0,attotime::from_hz(500));  // USART clock - this is a guesstimate
+	m_serial_timer->adjust(attotime::from_hz(19225),0,attotime::from_hz(19225));  // USART clock - this value loads a real tape
 	m_timer_bit = 0;
+	m_cass_state = 1;
+	m_cass_data[0] = 0;
+	m_cass_data[1] = 0;
+	m_cass_data[2] = 0;
+	m_cass_data[3] = 0;
 	m_beep->set_state(0);
 	m_beep->set_frequency(950);    /* piezo-device needs to be measured */
 }
@@ -412,11 +427,34 @@ static const i8251_interface alphatro_usart_interface =
 	DEVCB_NULL
 };
 
+TIMER_DEVICE_CALLBACK_MEMBER(alphatro_state::alphatro_c)
+{
+	m_cass_data[3]++;
+
+	if (m_cass_state)
+		m_cass->output(BIT(m_cass_data[3], 0) ? -1.0 : +1.0); // 2400Hz
+	else
+		m_cass->output(BIT(m_cass_data[3], 1) ? -1.0 : +1.0); // 1200Hz
+}
+
+TIMER_DEVICE_CALLBACK_MEMBER(alphatro_state::alphatro_p)
+{
+	/* cassette - turn 1200/2400Hz to a bit */
+	m_cass_data[1]++;
+	UINT8 cass_ws = (m_cass->input() > +0.03) ? 1 : 0;
+
+	if (cass_ws != m_cass_data[0])
+	{
+		m_cass_data[0] = cass_ws;
+		m_cass_data[2] = ((m_cass_data[1] < 12) ? 1 : 0);
+		m_cass_data[1] = 0;
+	}
+}
+
 static const cassette_interface alphatro_cassette_interface =
 {
 	cassette_default_formats,
 	NULL,
-	//(cassette_state) (CASSETTE_STOPPED | CASSETTE_MOTOR_ENABLED | CASSETTE_SPEAKER_ENABLED),
 	(cassette_state) (CASSETTE_PLAY | CASSETTE_MOTOR_DISABLED | CASSETTE_SPEAKER_ENABLED),
 	"alphatro_cass",
 	NULL
@@ -446,13 +484,14 @@ static MACHINE_CONFIG_START( alphatro, alphatro_state )
 	MCFG_SOUND_WAVE_ADD(WAVE_TAG, "cassette")
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)
 
-
 	/* Devices */
 	MCFG_MC6845_ADD("crtc", MC6845, XTAL_12_288MHz / 8, alphatro_crtc6845_interface) // clk unknown
 
 	MCFG_I8251_ADD("usart", alphatro_usart_interface)
 
 	MCFG_CASSETTE_ADD("cassette", alphatro_cassette_interface)
+	MCFG_TIMER_DRIVER_ADD_PERIODIC("alphatro_c", alphatro_state, alphatro_c, attotime::from_hz(4800))
+	MCFG_TIMER_DRIVER_ADD_PERIODIC("alphatro_p", alphatro_state, alphatro_p, attotime::from_hz(40000))
 
 	MCFG_RAM_ADD("ram")
 	MCFG_RAM_DEFAULT_SIZE("64K")