Microkit: Working machine. [Robbbert]

src/mame/drivers/microkit.cpp

@@ -1,5 +1,5 @@
 // license:BSD-3-Clause
-// copyright-holders:Curt Coder
+// copyright-holders:Curt Coder, Robbbert
 /*
 
     RCA COSMAC Microkit
@@ -7,36 +7,25 @@
     http://www.vintagecomputer.net/browse_thread.cfm?id=511
 
     Press CR or LF to get the * prompt.
-    Commands:
+    Commands (must be in UPPERcase):
     $Pxxxx - Jump to address xxxx
     ?Mxxxx yyyy - Dump memory starting at xxxx for yyyy bytes
-    !Mxxxx yy zz... - Write data (yy etc) to memory xxxx. Data gets entered when you
+    !Mxxxx yyzz... - Write data (yy etc) to memory xxxx onwards.
-                      press the space after the data.
 
     There's no sound or storage facilities, therefore no software.
 
-    ToDo:
+    The computer looks like a rack-mount metal box with a rudimentary front panel.
-    - No technical manual or schematic available, so the entire driver is bodgy guesswork.
+    - Buttons are: Reset; Load; Run program; Run Utility
-    - Address 0 needs to be read/writeable, otherwise the numbers you enter will get
+    - There is a RUN LED.
-            internally corrupted.
+    - It also has a power switch and lamp, and a fuse.
-    - Address 8000 is IDL which hangs the system, so program counter is preset to 8001.
+    - According to the schematic there are LEDs on every data, address and status line.
-    - The keyboard is hooked up serially, which is ok, but the output to the terminal
-            is rubbish, so parallel is used so you can at least see something.
-    - When you enter commands, you can't see what you're doing.
-    - When you enter numbers, they display as rubbish or act as control codes. They
-            internally work though.
-    - The computer looks like a rack-mount metal box with a rudimentary front panel.
-            Buttons are: Reset; Load; Run program; Run Utility
-            There is a RUN LED.
-            None of these items are emulated.
-            It also has a power switch and lamp, and a fuse.
 
 *****************************************************************************************/
 
 #include "emu.h"
 #include "cpu/cosmac/cosmac.h"
 #include "bus/rs232/rs232.h"
-#include "machine/terminal.h"
+#include "machine/cdp1852.h"
 
 
 class microkit_state : public driver_device
@@ -44,13 +33,18 @@ class microkit_state : public driver_device
 public:
 	microkit_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
+		, m_a15(1)
 		, m_maincpu(*this, "maincpu")
+		, m_rom(*this, "maincpu")
 		, m_rs232(*this, "rs232")
-		, m_terminal(*this, "terminal")
 	{ }
 
 	void microkit(machine_config &config);
 
+	DECLARE_INPUT_CHANGED_MEMBER(reset_button);
+	DECLARE_INPUT_CHANGED_MEMBER(runp_button);
+	DECLARE_INPUT_CHANGED_MEMBER(runu_button);
+
 private:
 	DECLARE_READ_LINE_MEMBER(clear_r);
 	DECLARE_WRITE8_MEMBER(ram_w);
@@ -59,63 +53,106 @@ private:
 	void microkit_io(address_map &map);
 	void microkit_mem(address_map &map);
 
+	virtual void machine_start() override;
 	virtual void machine_reset() override;
+	std::unique_ptr<uint8_t[]> m_ram;
 	uint8_t m_resetcnt;
-	uint8_t m_ram_data;
+	bool m_a15;
 	required_device<cosmac_device> m_maincpu;
+	required_memory_region m_rom;
 	required_device<rs232_port_device> m_rs232;
-	required_device<generic_terminal_device> m_terminal;
 };
 
 void microkit_state::microkit_mem(address_map &map)
 {
-	map(0x0000, 0x0000).rw(FUNC(microkit_state::ram_r), FUNC(microkit_state::ram_w));
+	map(0x0000, 0x01ff).rw(FUNC(microkit_state::ram_r),FUNC(microkit_state::ram_w));
-	map(0x8000, 0x81ff).rom().region("maincpu", 0);
+	map(0x0200, 0x0fff).ram();
-	map(0x8200, 0x83ff).ram();
+	map(0x8000, 0x81ff).rom().region("maincpu", 0);  // CDP1832.U2
+	map(0x8c00, 0x8c1f).ram();   // CDP1824.U3 "Register Storage"
 }
 
 void microkit_state::microkit_io(address_map &map)
 {
-	map(0x07, 0x07).nopw(); // writes a lots of zeros here
+	map(0x05, 0x05).r("u4", FUNC(cdp1852_device::read)).w("u4", FUNC(cdp1852_device::write));   // user output port
+	map(0x06, 0x06).r("u5", FUNC(cdp1852_device::read)).w("u5", FUNC(cdp1852_device::write));   // user input port
+	map(0x07, 0x07).nopw(); // writes lots of zeros here
 }
 
 static INPUT_PORTS_START( microkit )
+	PORT_START("RESET")
+	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RESET") PORT_CODE(KEYCODE_F3) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, reset_button, nullptr)
+	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RUN P") PORT_CODE(KEYCODE_F2) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, runp_button, nullptr)
+	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RUN U") PORT_CODE(KEYCODE_F1) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, runu_button, nullptr)
 INPUT_PORTS_END
 
+INPUT_CHANGED_MEMBER(microkit_state::reset_button)
+{
+	m_maincpu->set_input_line(INPUT_LINE_RESET, newval ? ASSERT_LINE : CLEAR_LINE);
+	m_resetcnt = 0;
+}
+
+INPUT_CHANGED_MEMBER(microkit_state::runp_button)
+{
+	m_a15 = 0;
+	m_resetcnt = 0;
+	m_maincpu->set_input_line(INPUT_LINE_RESET, newval ? ASSERT_LINE : CLEAR_LINE);
+}
+
+INPUT_CHANGED_MEMBER(microkit_state::runu_button)
+{
+	m_a15 = 1;
+	m_resetcnt = 0;
+	m_maincpu->set_input_line(INPUT_LINE_RESET, newval ? ASSERT_LINE : CLEAR_LINE);
+}
+
 READ_LINE_MEMBER( microkit_state::clear_r )
 {
-	if (m_resetcnt < 0x10)
-		m_maincpu->set_state_int(cosmac_device::COSMAC_R0, 0x8001); // skip IDL
 	if (m_resetcnt < 0x20)
 		m_resetcnt++;
-	// set reset pin to normal
+
-	return 1;
+	if (m_resetcnt < 0x10)
+		return 0;
+	else
+	if (m_resetcnt == 0x1c)
+		m_a15 = 0;
+
+		return 1;
 }
 
 READ8_MEMBER( microkit_state::ram_r )
 {
-	return m_ram_data;
+	if (m_a15)
+		return m_rom->base()[offset];
+	else
+		return m_ram[offset];
 }
 
 WRITE8_MEMBER( microkit_state::ram_w )
 {
-	m_ram_data = data;
+	m_ram[offset] = data;
-	if (data > 0 && data < 0x80)
-		m_terminal->write(data);
 }
 
 void microkit_state::machine_reset()
 {
 	m_resetcnt = 0;
-	m_ram_data = 0;
+	m_maincpu->reset();
+}
+
+void microkit_state::machine_start()
+{
+	// Register save state
+	save_item(NAME(m_resetcnt));
+	save_item(NAME(m_a15));
+	m_ram = make_unique_clear<uint8_t[]>(0x200);
+	save_pointer(NAME(m_ram), 0x200);
 }
 
 static DEVICE_INPUT_DEFAULTS_START( serial_keyb )
 	DEVICE_INPUT_DEFAULTS( "RS232_TXBAUD", 0xff, RS232_BAUD_300 )
 	DEVICE_INPUT_DEFAULTS( "RS232_RXBAUD", 0xff, RS232_BAUD_300 )
 	DEVICE_INPUT_DEFAULTS( "RS232_STARTBITS", 0xff, RS232_STARTBITS_1 )
-	DEVICE_INPUT_DEFAULTS( "RS232_DATABITS", 0xff, RS232_DATABITS_8 )
+	DEVICE_INPUT_DEFAULTS( "RS232_DATABITS", 0xff, RS232_DATABITS_7 )
-	DEVICE_INPUT_DEFAULTS( "RS232_PARITY", 0xff, RS232_PARITY_NONE )
+	DEVICE_INPUT_DEFAULTS( "RS232_PARITY", 0xff, RS232_PARITY_MARK )
 	DEVICE_INPUT_DEFAULTS( "RS232_STOPBITS", 0xff, RS232_STOPBITS_2 )
 DEVICE_INPUT_DEFAULTS_END
 
@@ -123,23 +160,34 @@ DEVICE_INPUT_DEFAULTS_END
 void microkit_state::microkit(machine_config &config)
 {
 	// basic machine hardware
-	CDP1802(config, m_maincpu, 1750000);
+	CDP1802(config, m_maincpu, 2_MHz_XTAL);
 	m_maincpu->set_addrmap(AS_PROGRAM, &microkit_state::microkit_mem);
 	m_maincpu->set_addrmap(AS_IO, &microkit_state::microkit_io);
 	m_maincpu->wait_cb().set_constant(1);
 	m_maincpu->clear_cb().set(FUNC(microkit_state::clear_r));
+	m_maincpu->q_cb().set(m_rs232, FUNC(rs232_port_device::write_txd)).invert();
 
 	/* video hardware */
-	RS232_PORT(config, m_rs232, default_rs232_devices, "keyboard");
+	RS232_PORT(config, m_rs232, default_rs232_devices, "terminal");
 	m_rs232->rxd_handler().set_inputline(m_maincpu, COSMAC_INPUT_LINE_EF4);
-	m_rs232->set_option_device_input_defaults("keyboard", DEVICE_INPUT_DEFAULTS_NAME(serial_keyb));
+	m_rs232->set_option_device_input_defaults("terminal", DEVICE_INPUT_DEFAULTS_NAME(serial_keyb));
-	GENERIC_TERMINAL(config, m_terminal, 0);
+
+	cdp1852_device &u4(CDP1852(config, "u4"));
+	u4.mode_cb().set_constant(1); // output
+
+	cdp1852_device &u5(CDP1852(config, "u5"));
+	u5.mode_cb().set_constant(0); // input
 }
 
 ROM_START( microkit )
-	ROM_REGION( 0x200, "maincpu", ROMREGION_INVERT )
+	ROM_REGION( 0x200, "maincpu", 0 )
-	ROM_LOAD( "3.2b", 0x000, 0x100, CRC(6799357e) SHA1(c46e3322b8b1b6534a7da04806be29fa265951b7) )
+	ROM_LOAD( "ut4.u2", 0x0000, 0x0200, CRC(ba642f8e) SHA1(8975a4c6a0bb699b53c753946aac54860054246a) )
-	ROM_LOAD( "4.2a", 0x100, 0x100, CRC(27267bad) SHA1(838df9be2dc175584a1a6ee1770039118e49482e) )
+
+	// These are bad, with heaps of bugs
+	//ROM_REGION( 0x200, "maincpu", ROMREGION_INVERT )
+	//ROM_LOAD( "3.2b", 0x000, 0x100, CRC(6799357e) SHA1(c46e3322b8b1b6534a7da04806be29fa265951b7) )
+	//ROM_LOAD( "4.2a", 0x100, 0x100, CRC(27267bad) SHA1(838df9be2dc175584a1a6ee1770039118e49482e) )
+
 ROM_END
 
-COMP( 1975, microkit, 0, 0, microkit, microkit, microkit_state, empty_init, "RCA",  "COSMAC Microkit",  MACHINE_IS_SKELETON )
+COMP( 1975, microkit, 0, 0, microkit, microkit, microkit_state, empty_init, "RCA", "COSMAC Microkit", MACHINE_SUPPORTS_SAVE )