Convert from 16f877a to 18f458

[Ron Marcus]

I have reached the memorylimit, and wants to convert the program to a 458-device.
I have selected the 18f458 in Microcodestudio, and compiled.
In MPLAB I select the config. bits and set osc to HS( Like I did for 877a).
The oscillator does not start, and the device is not working at all.

Hints?

I've used the 452 for quite some time now.I have had no issues. Are you using a crystal or resonator? Have you tried a simple loop program to flash a LED or make a sound? There are different registers to config at start up, and there could be a number of mechanical reasons it doesn't work either. Have you tried substituting the processor with a spare?

Ron