Below is a very brief guide to getting started with the Z80 motherboard (SC114).

It is assumed the Z80 motherboard is fully assembled, but with no modules fitted in the RC2014 bus sockets. The ROM should contain the Small Computer Monitor v1.0 configuration S2 (available from http://www.scc.me.uk).

Connect a suitable FTDI style TTL level serial to USB adapter from P1 to a powered USB socket on a PC (or similar). The table below describes the typical connections from a USB adapter to the Z80 motherboard.

USB Adapter	Direction	Motherboard
1 = GND	< – >	1 = GND
2 = /CTS in	<<<<<	2 = /RTS out
3 = Vcc (5V)	< – >	3 = Vcc (5V)
4 = TXD out	>>>>>	4 = RXD in
5 = RXD in	<<<<<	5 = TXD out
6 = /DTR or /RTS out	>>>>>	6 = /CTC in

Press the reset button and check the LED lights. It should flash off and on again either once or twice.

• One flash off and on indicates a serial module has been detected on the RC2014 bus and is being used to connect to a terminal. Serial modules usually work at 115200 baud, 8 data bits, 1 stop bit, no parity and hardware flow control (RTS/CTS).

• Two flashes off and on indicate a serial module has not been detected and the onboard serial port (P1) is being used to connect to a terminal. This port works at 9600 baud, 8 data bits, 1 stop bit, no parity and hardware flow control (RTS/CTS).

• If the LED continues to flash the self-test has failed, most likely indicating the RAM is not working.

Start a suitable terminal emulation program, such as Tera Term, on the PC. Configure the PC’s serial port as indicated above.

Press the reset button on the Z80 motherboard. You should see the terminal program display something like “Small Computer Monitor – SC114”.

You are now ready to play!

This would be a good time to read the Small Computer Monitor tutorial and user guide.

Port Addresses