diff --git a/src/mame/drivers/microkit.c b/src/mame/drivers/microkit.c
index 9082931f21f..2d225dc65ff 100644
--- a/src/mame/drivers/microkit.c
+++ b/src/mame/drivers/microkit.c
@@ -6,35 +6,126 @@
 
     http://www.vintagecomputer.net/browse_thread.cfm?id=511
 
-*/
+    Press CR or LF to get the * prompt.
+    Commands:
+    $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
+                      press the space after the data.
+
+    There's no sound or storage facilities, therefore no software.
+
+    ToDo:
+    - No technical manual or schematic available, so the entire driver is bodgy guesswork.
+    - Address 0 needs to be read/writeable, otherwise the numbers you enter will get
+            internally corrupted.
+    - Address 8000 is IDL which hangs the system, so program counter is preset to 8001.
+    - 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"
+
 
 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_maincpu(*this, "maincpu")
+		, m_rs232(*this, "rs232")
+		, m_terminal(*this, "terminal")
 	{ }
+
+	DECLARE_READ_LINE_MEMBER(clear_r);
+	DECLARE_WRITE8_MEMBER(ram_w);
+	DECLARE_READ8_MEMBER(ram_r);
+
+private:
+	virtual void machine_reset();
+	UINT8 m_resetcnt;
+	UINT8 m_ram_data;
+	required_device<cosmac_device> m_maincpu;
+	required_device<rs232_port_device> m_rs232;
+	required_device<generic_terminal_device> m_terminal;
 };
 
 static ADDRESS_MAP_START( microkit_mem, AS_PROGRAM, 8, microkit_state )
-	AM_RANGE(0x0000, 0x01ff) AM_ROM AM_REGION("maincpu", 0)
+	AM_RANGE(0x0000, 0x0000) AM_READWRITE(ram_r,ram_w)
+	AM_RANGE(0x8000, 0x81ff) AM_ROM AM_REGION("maincpu", 0)
+	AM_RANGE(0x8200, 0x83ff) AM_RAM
 ADDRESS_MAP_END
 
 static ADDRESS_MAP_START( microkit_io, AS_IO, 8, microkit_state )
+	AM_RANGE(0x07, 0x07) AM_WRITENOP // writes a lots of zeros here
 ADDRESS_MAP_END
 
 static INPUT_PORTS_START( microkit )
 INPUT_PORTS_END
 
+READ_LINE_MEMBER( microkit_state::clear_r )
+{
+	if (m_resetcnt < 0x10)
+		m_maincpu->set_state_int(COSMAC_R0, 0x8001); // skip IDL
+	if (m_resetcnt < 0x20)
+		m_resetcnt++;
+	// set reset pin to normal
+	return 1;
+}
+
+READ8_MEMBER( microkit_state::ram_r )
+{
+	return m_ram_data;
+}
+
+WRITE8_MEMBER( microkit_state::ram_w )
+{
+	m_ram_data = data;
+	if (data > 0 && data < 0x80)
+		m_terminal->write(space, 0, data);
+}
+
+void microkit_state::machine_reset()
+{
+	m_resetcnt = 0;
+	m_ram_data = 0;
+}
+
+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_PARITY", 0xff, RS232_PARITY_NONE )
+	DEVICE_INPUT_DEFAULTS( "RS232_STOPBITS", 0xff, RS232_STOPBITS_2 )
+DEVICE_INPUT_DEFAULTS_END
+
+
 static MACHINE_CONFIG_START( microkit, microkit_state )
 	// basic machine hardware
-	MCFG_CPU_ADD("maincpu", CDP1801, 2000000)
+	MCFG_CPU_ADD("maincpu", CDP1802, 1750000)
 	MCFG_CPU_PROGRAM_MAP(microkit_mem)
 	MCFG_CPU_IO_MAP(microkit_io)
 	MCFG_COSMAC_WAIT_CALLBACK(VCC)
+	MCFG_COSMAC_CLEAR_CALLBACK(READLINE(microkit_state, clear_r))
+
+	/* video hardware */
+	MCFG_RS232_PORT_ADD("rs232", default_rs232_devices, "keyboard")
+	MCFG_RS232_RXD_HANDLER(DEVWRITELINE("maincpu", cosmac_device, ef4_w))
+	MCFG_DEVICE_CARD_DEVICE_INPUT_DEFAULTS("keyboard", serial_keyb)
+	MCFG_DEVICE_ADD("terminal", GENERIC_TERMINAL, 0)
 MACHINE_CONFIG_END
 
 ROM_START( microkit )