vx-3000

Greetings everyone!! I have three VX-3000 radios and I can't seem to program any of them. I have tried two aftermarket VPL-1 cables from eBay and several other RS232 to TTL devices. I have tried several computers, P4, 486, 286. I have tried Windows XP and MSDOS. When I start CE19D(4.04), I...