Need to edit a HEX file

[NL7Z]

I have a 16F84A PIC chip that has been running a 6m beacon here in Alaska for the last 10 years..now I have changed my call and need to change the call on the beacon.
I have a programmer for that PIC, however I have no idea how to edit the existing information to reflect the new call.
I can read the chip, look at the HEX, and rewrite the chip.
Can someone point me to a program that I can actually see whet I need to edit..or better yet I could send the HEX file to someone and have them do the edit.
Thanks
Kevin

KL7KY  ex NL7Z

[STAYVERTICAL]

Try Hexedit

http://www.physics.ohio-state.edu/~prewett/hexedit/

I downloaded it, quickly edited a file and in the ASCII window changed some stuff.
Then saved it, and checked it, then changed it back.
It all seemed to work ok.
I am using windows 7 - this program is standalone and does not need to be installed.
You may however, need to run it with administrator privileges depending on your P.C. setup.

I am not familiar with your PIC chip/etc but I would download the hex file to a P.C., edit a copy and when you are satisfied that all is OK, download to the PIC.
Remember - keep a copy of the original file, in case something goes wrong, so you can get back to square one.

Good luck es 73 - Rob

[G4IJE]

Is editing the file the issue, or is it knowing what needs to be changed? The file is unlikely to show ASCII values representing the letters in the callsign. There may be a look-up table or the morse characters might just be hard-coded. When I used to do this stuff with 8-bit micros and EPROM-based systems, I would often use an 8-bit port to give 8 separate messages. Unless you know the method used to encode "key up" and "key down" it would be very hard to work out how to change the message just by looking at the HEX code.

[WB8VLC]

Your .hex file could have been compiled using a particular C or even a Pbasic compiler so simply changing the hex file, if you could even find the correct locations to change, may not work.

You should also have a .asm file available along with the .HEX file and some other files needed by MPLAB but the .asm file is the main one that you want so that you can change the call sign correctly in the assembly code.

You need to edit the .asm file with the new call sign and then using MPLAB make up a new project file with all other support files such as the 16F84A.inc file and possibly even some additional included .h files will probably be required depending on the compiler that was originally used to generate the code.

 If you had some of the high level code used such as C or possibly even any of the numerous Picbasic compilers then your all set at changing the call sign and recompiling the code but you'd still need the high level compiler for this which it appears you don't have.

 With the modified .asm file you need to next compile everything into a new .hex file for programming into the pic which would be easier.

  You probably should go over to microchips site and download a copy of of MPLAB and become familiar with it first then try and find out more information on how the morse routine for your beacon program works.

Also where did you get the original beacon program from, there may be more information available on how it works out on the web or I may even have something similar to yours that's available.

[WB8VLC]

Kevin,

 If none of this works then I may be able to make up a new ID'r board for you with the desired message.

 I need to know what the keying logic level is on your beacon?

 It's probably active low Tx/PTT  but it's still probably a good idea to ask for as much information as possible on your beacon.

Mike

[WB8VLC]

another thing I just realized, if this is one of the IK2BCP style of beacons with the PTT output on pin 6 of the pic, using a 4 MHz crystal oscillator, and the beacon PTT output driving a common emitter inverter transistor then I can regenerate a new 16F84A hex file for you to program into the PIC.

If your circuit is using a different output pin then I can still regenerate a  hex file for your use but you would need to make 2 minor mods to your board to make this code work other wise it could be lengthy software changes.


Mike

[EI7IR]

You could use the ID-O-Matic 2 kit ($25.00) available at www.hamgadgets.com which you can change numerous settings including callsign,ID intervals,TOT etc just to mention a few.There are also other uses for this kit might be worth a try.

Paraic

[KG4RUL]

You could use the ID-O-Matic 2 kit ($25.00) available at www.hamgadgets.com which you can change numerous settings including callsign,ID intervals,TOT etc just to mention a few.There are also other uses for this kit might be worth a try.

Paraic

I built one up for our ARES backup repeater.  Easy to build an program AND the price is right.

[WB6RXG]

Ultraedit-32 for windows has a HEX mode.

73,
Stuart
WB6RXG