x-rayman thanks again for your two responses.

FYI I'm in West Yorkshire.

If I switch the lathe on, the cooling fan starts, but no beep.

I used the F6 key to enter Machine Mode. I also pressed ALT + P and entered 'conectl' password, which it appeared to accept OK. I did at one point get an 'on' response next to 'Machine Control' in the menu, but the programme became unresponsive after that. I tried a few times with the same result.

I used serial1=directserial realport:com1 in my DOSbox config file, but didn't get far and hence why I used the old Win98 laptop with a serial port.

The USB - Serial cable I used is a UGreen model using the Prolific PL2303 Chipset and it appears to be recognised OK by Windows 10, although I haven't specifically tested it.

I won't get a chance to investigate further until Sunday.

Thanks Again