Vm134 + pic16f873a


I have a problem programming PIC16F873A with an VM134. After writing, the program checks the software then crates an message “error writing to PIC”.
Input voltage: 15,2V, VPP=12,8 Volt, raised to 13,2V. Baud rate set lower on PC (COM1, card in a PCI slot), does not give a better result. Brown out reset enabled, Watchdog timer enabled, Writing enabled, XT osc.
The strange part is that some PIC’s have been programmed, (I can read the software in the PIC) and some will not. If I put an original PIC with software in the experiment-board, everything works fine. If I put a programmed PIC (programmed by me via VM134) in the experiment-board nothing works.

Does anyone have a idea of what is going wrong?


It’s difficult to answer…

You must be sure that VPP is between 13V…13,5V
If programming doesn’t work, try to increase the hardware delay setting.