• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

GM300 o M120? long beep on power-on

RicPortilloR

Newbie
Joined
Oct 4, 2025
Messages
3
Reaction score
0
I have a radio that when turned on it makes a long beep and according to the chassis serial number D33MJA73A5CK (Maxtrac 300 16ch) but the radio doctor when reading it says M33GMC29C2__ (M120 16ch unserialized) it connects, reads it but does not let you write anything and gives an error "check error" "external CP write error" I can also connect with the software (DosBox) Maxtrac M12, GM300 but I still can't write any codeplug and it says "Error Number 2 Has Occurred: Serial Bus Error Make sureradio is turned on. Check RIB power cables & connections" I'm not sure I have the correct file. Any ideas? Thanks

Tengo un radio que al encender suena un bip largoy que segun el serial del chacis D33MJA73A5CK (Maxtrac 300 16ch) pero el radio doctor al leerlo dice M33GMC29C2__ (M120 16ch sin seriar) se conecta lo lee pero no deja escribir nada da erro ¨cheksun error ¨ ¨external CP write error¨ tambien puedo conectarme con los softwere (DosBox) Maxtrac M12, GM300 pero igual no puedo escribir nigun codeplug dice ¨Error Numbre 2 Has Occurred: Serial Bus Error Make sureradio is turned on. Check RIB power cables & connections¨ no estoy seguro de tener el archivo correcto. Alguna idea? Gracias
 

n7maq-1

Member
Premium Subscriber
Joined
Mar 12, 2004
Messages
288
Reaction score
216
Location
Oregon
Hello,

The pictures you posted are of a Maxtrac, not GM300. It sounds like someone has forced a GM300 codeplug into that radio. I forget the correct RSS for the GM300 but there is a homebrew software package that will run under windows, if you search for it it will pop up.

First thing you need to do is get an older 1995 to 2000 era computer with a real RS232 port and a DOS OS, no USB to Serial, and defiantly no DOSBox, that is just asking for more problems. Even if someone forced a codeplug in you may be ale to restore it to a Maxtrac with the correct level of RSS assuming there is not any hardware related issues (that is at least a 25 year old radio)

Below are some links to a great deal of information on Maxtracs and RSS.



Again, find an old computer (386 or older, though I have used an early Pentium with DOS RSS without any issues from Maxtrac, or GM300 RSS) running or booted into DOS. Only then should you continue. That may be the only problem aside from the forced codeplug.

Good luck and keep us updated.


Thanks,

Jim
 

RicPortilloR

Newbie
Joined
Oct 4, 2025
Messages
3
Reaction score
0
Hello, thanks for the explanation. All my clues point in that direction. I think I can find a not-so-old PC with a serial port. I'm going to look for the right rib, but I still have doubts or problems about which codeplug to use.
 

n7maq-1

Member
Premium Subscriber
Joined
Mar 12, 2004
Messages
288
Reaction score
216
Location
Oregon
Hello, thanks for the explanation. All my clues point in that direction. I think I can find a not-so-old PC with a serial port. I'm going to look for the right rib, but I still have doubts or problems about which codeplug to use.
If you are able to read it and write back I would leave it as is.

By the way the home brew software is called GM300 Radio Doctor, it is or was free.
 
Top