This is a WIP and should be ignored. Information might be wrong, your radio might blow up

Icom IC-F110/F210 Instruction Booklet

Icom OPC-617 Auxiliary Cable

Icom IC-F210 Service Manual

Initial indications suggest IC-F2XX is UHF, IC-F1XX is VHF. Note that the UHF models come in “Low” and “Highband” versions, neither of which cover 430-440MHz. HOWEVER, I have a high band version and its accepted 430 MHz fine. If I attempt to program a VHF frequency it'll program fine but then the channel name will flash indicating a fault. I am yet to test RF performance beyond keying up the radio and checking it transmits

Documented pinouts for the cable show a MAX232 IC, suggesting the radio requires TTL Levels.

Note that ICOM documentation reverses the standard pin numbering associated with RJ45 connectors. If you're looking at the connector from above (with the tab below) and the gold contacts facing away from you, Pin 8 is on the left, and pin 1 is on the right.

The following table uses the same reversed pin number to avoid confusion (hopefully). TODO: Should we reverse this?

https://www.qsl.net/g4wpw/hm100.html

PTT tested and confirmed, but no tested audio.

Some radios have an optional female DB9 cable fitted