Jim Corenman built in a CAT feature to Airmail that does frequency and mode control of the HF radio under program control. There are some Pactror modems that have CAT built in ( e.g. PTCII ) but many others don't ( e.g. PK232, PTCIIe). This feature is invaluable as it sets the connect up on the correct frequency, sideband, offset automatically when the desired station is selected in the terminal mode. He supports various radio makes. I have Icoms so this note is about them. Others are similar.
Icom CAT is called CI-V and is an bidirectional single-wire serial asynchronus mode using TTL levels . The Icom interface is called a CT17 and requires a serial port and costs $150. A USB dongle is available that does the job. I got mine on Ebay from kawamall_cool (!) for less than $9 incl shipping.
Here is a pix of the dongle and driver miniCD. Note "mono" 3.5mm plug
The dongle is based on the Prolific USB-to-Serial Bridge chip. I have a 32 bit OS (XPSP3) but drivers for others incl W7 64 bit are included. It would probably be smart to check the Prolific web site for the most up-to-date driver.
Here are my notes and step-by-step:
[A note- I have the original PTCII and have used the built in CAT hardware for more than 10 yrs. It works well but I changed over to the scheme described above so I can use the PTCII (Airmail) and SignalLink (RMS Express-Winmor) without changing cables]
WINMOR- (A "sound card" TNC to support RMS Express over HF radio)- Here are notes to use the dongle to control an Icom radio with this.SATPC32- (A program to do "one-true-rule" uplink and downlink doppler tuning for amateur radio satellite comms) Here are notes on setting up an IC-910 for CAT control with this program.
de W4AVO 9-30-2012