I’ve recently started working with surplus Motorola GM300 mobile VHF and UHF transceivers for amateur radio use. These can be found for ~ $50 on eBay, and are easily programmed using RadioDoctor software under Windows XP. I found an older laptop in the techno trash at work, reloaded XP, and have dedicated this laptop to GM300 use. Since XP is no longer supported, I’ll keep it off-line.
I’m using a DB-9 to RJ-45 ribless cable, also purchased on eBay, to program these radios. My laptop has a built-in, hardware serial port.