GM300 programming problems

[68hc11]

Hello all,

I do servicing for myself and few friends who are into amateur radio. Last week I was given a GM300 to try to program for repeater operation on VHF. The radio is a mystery, it is the VHF version with 2-layer logic board but I cannot tell anything else because the sticker is missing. I wanted to read the model number with the RSS and then possibly program the desired channels.

I tried to access it with several versions of RSS but it does not answer at all. I monitor the SCI+ line with oscilloscope during programming to avoid any confusion. The transmit pin on the microcontroller inside the radio is always high and does not respond to the RSS. The RX pin is receiving serial communication.

I have a clone of the original RIB which works with other radios OK. I've tried a few versions of GM300 RSS (R02, R03, R04) and the MaxTrac LAB RSS - all of them fail the COMM TEST with error "Invalid opcode". Needless to say they also do not read the codeplug. I do not think the logic board is dead because the radio otherwise works, there are 2 channels programmed and it reacts to keyboard presses and PTT, unsquelches and outputs audio (noise) when i hold down the MON button.

I am using a 486-class machine with RS232 port and MS-DOS 6.22

Did anyone of you see something like that before?

 

[Martin-ZS4E]

Hello all,

I do servicing for myself and few friends who are into amateur radio. Last week I was given a GM300 to try to program for repeater operation on VHF. The radio is a mystery, it is the VHF version with 2-layer logic board but I cannot tell anything else because the sticker is missing. I wanted to read the model number with the RSS and then possibly program the desired channels.

I tried to access it with several versions of RSS but it does not answer at all. I monitor the SCI+ line with oscilloscope during programming to avoid any confusion. The transmit pin on the microcontroller inside the radio is always high and does not respond to the RSS. The RX pin is receiving serial communication.

I have a clone of the original RIB which works with other radios OK. I've tried a few versions of GM300 RSS (R02, R03, R04) and the MaxTrac LAB RSS - all of them fail the COMM TEST with error "Invalid opcode". Needless to say they also do not read the codeplug. I do not think the logic board is dead because the radio otherwise works, there are 2 channels programmed and it reacts to keyboard presses and PTT, unsquelches and outputs audio (noise) when i hold down the MON button.

I am using a 486-class machine with RS232 port and MS-DOS 6.22

Did anyone of you see something like that before?

Hi,

I am experiencing a similar problem, also get "invalid opcode" error message.
I am using Win10 with VMWare 16 with DOS 6.22 installed.
Original Motorola RIB box and GM300 software,
Strange thing is all worked 100% until my SSD crashed recently and I reloaded Windows and all my other software.
I have a feeling the problem is related to memory setting in DOS, hopefully someone will be able to clarify the exact nature of the error message.