I can end your troubles.
1. Purchase a Tripplite USA-19HS Serial Adapter
2. Purchase a Serial Programming cable for a Motorola HT-1250
3. Start your computer with the Tripplite Serial Adapter plugged into it.
4. Start CPS Programming software.
5. Turn on your radio.
6. Either upload, or program your radio.
I tried everything in an effort to successfully program my HT-1250's, but nothing I tried worked. Then, a very experienced friend told me about the Tripplite Serial Adapters and also told me that he had 100% success with them. (So far, I have had 100% success as well). Likewise, don't substitute with another serial adapter. Use only a Tripplite adapter. You can find the Tripplite serial adapter and Motorola Serial programming cords on Amazon. I got a Kawamall serial programming cable (for HT-1250) and it works great. With this Tripplite serial adapter, you'll be able to program your HT-1250 from an version of Windows, and/or from a Mac. (I recommend Windows and a PC though because that is what CPS was designed for. Happy Programming. Happy Holidays.