To build a serial cable to connect your PC to a real Spectrum
A standard null-modem cable will not work when connected to a real ZX Interface 1 and a serial (COM) port on your computer.
You will need to build a special cable as detailed below. On the ZX Interface 1 side, you will need a male 9-pin D-connector. On the PC side, you will need a female 9-pin D-connector. Connect the two together using six core cable as shown below:
PC |
ZX Interface 1 |
|---|---|
2 - RD |
3 - TD |
3 - TD |
2 - RD |
5 - GND |
7 - GND |
7 - RTS |
4 - CTS |
8 - CTS |
5 - RTS |
1 - DCD |
9 - DTR |
Tip
Normally, you want to configure the same COM port for both input and output. However, sometimes it can be useful to say, configure serial input to a COM port and serial output to a file. This way it's possible to receive data from a real Spectrum and write it to a local file on your computer.