My first programmable scanner was a "Bearcat" Model 101, 16 channel scanner VHF/UHF. This scanner is programmable by enabling/disabling 16 switches on the front panel in a code (on off , zeros or ones) for most public safety frequencis that was in the instruction manual. If a frequency was not in the book, there was a formula you would have to apply to the frequency in order to get "codes" required onto a worksheet. Sure has heck solved the problem of buying crystals for the fixed receivers OR using a tunable scanner. I still have this scanner in storage.. Perhaps I should use it for some of the known area frequencies.