Hi PICList, long time no problem, time to change that! :)  Someone smack
me, I have to be doing something absurd.

I can't get the flippin' TMR0 interrupt to fire on the 18F2320.  I can
get the TMR0IF flag to trigger, I can poll it and see it happen, that
works no problem, so I know the timer is running, and overflowing
correctly.  I just can't get the actual low_priority ISR to be called,
could be a Hi-Tech C problem (my misuse of it most likely) so I'm not
sure.  I've tried simply setting TMR0IF and the interrupt still won't go
off.  I'm just trying to light a damn LED now when either ISR invokes.
Here's my current code, quite simple:

----- SNIP ----- ----- SNIP ----- ----- SNIP ----- ----- SNIP -----

void main() {
   init(); // setup ports, registers, etc...
   initPWM(); // start PWM sequence
   initInterrupts(); // setup interrupt masks, etc

   RB4 = RB5 = 1;

   while(1);
}

void init() {
   IRCF2 = IRCF1 = IRCF0 = 1; // 8MHz
   SCS1 = 1; // Internal oscillator select

   ADCON1 = 0x0C; // Internal ref, 2-0 Analog

   TRISA = 0b00111111; // See pinout
   TRISB = 0b11001111; // See pinout
   TRISC = 0b10000000; // See pinout
}

void initPWM() {
   T0CON = 0b01000110; // internal, 8-bit, 1:128 prescalar
   TMR0H = TMR0L = 0; // clear TMR0
   TMR0ON = 1; // turn on TMR0
}

void initInterrupts() {
   IPEN = 1; // enable interrupt priorities

   TMR0IP = 0; // TMR0 is low priority
   TMR0IE = 1; // enable TRM0 interrupt
   TMR0IF = 0; // clear pending interrupts

   GIEL = 1; // enable low priority interrupts
}

void interrupt ISR() {
   RB4 = 0;
}

void interrupt low_priority ISR_LOW() {
   RB5 = 0;
}

------ SNIP ------ ----- SNIP ----- ----- SNIP ----- ----- SNIP -----

This is my first venture into 18-series and interrupt priorities, so I'm
hoping I'm missing something, but the datasheet simply says to set the
priority, masking and enable low-priority interrupts and it should be
working, which makes sense, yet nothing it happening.

Suggestions are welcome! :)

Thanks in advance,
Nick Veys

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