LCD works at 4MHz, but not 12 or 16MHz

[Max Power]

Its working now. That was it. I added this:

DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 100

thank you so much, this forum is so helpful.

...yeah, I had to change XT_osc to HS_osc in order to get my 16MHz resonator to work at all. 12MHz seems to be ok with just XT_osc. Is there a frequency where you should start to use HS_osc?

thanks again.

[skimask]

...yeah, I had to change XT_osc to HS_osc in order to get my 16MHz resonator to work at all. 12MHz seems to be ok with just XT_osc. Is there a frequency where you should start to use HS_osc?

It's in the datasheets for your particular PIC.