As Codan have not released the software to the public to program the codan 9313 I had to think about it in a different way. For the record I did contact them asking to buy it (the software) and the reply was it is no longer available.
In my view if it is no longer available, it should be made public domain
In true amateur fashion I pulled the covers off and had a look…..
Inside on the control board is a 24C08 eeprom. I unsoldered this off the board and downloaded its contents.
The first frequency in the radio was 2020Khz for TX and RX. Looking through the eeprom, the first 7 addresses were: 07 E4 00 07 E4 00 27
Without going into lots of detail on working it out, here is the low down
So 07E4 in hex is 2020 Decimal (2020Khz), So to add the frequencies I wanted I changed these hex addresses and re-wrote the prom. I added 8022Khz, VKS-737 channel 2. I changed the line of code to: 1F 56 00 1F 56 00 27
And it worked!
To make a receive only frequency, change the TX addresses to 00 00, ie 1F 56 00 00 00 00 27
I did not try to add more than 15 Channels nor did I try to go above 24Mhz.
I used a Willem programmer to change the eeprom, however any eeprom programmer should do the trick. To make it easier to program the frequencies in the future, I removed the IC and instaled an IC socket in its location, so 2 screws later I can reprogram the channels to whatever I want.
If someone wants to send me an eeprom image with the scan channels added I would love to have a look.
Maybe I'll write a little VB Program that can create Codan eeprom images, or even better, program the radio via RS232.