Simple External Interrupt Handler

[Will]

I need to be able to run an ISR each time a line on a particular port changes. Sounds simple enough but I keep getting preprocessor errors when using any other port but B.

What am I missing? Below complies fine but doesn't seem to turn the

--
#include <16F877A.h>

#FUSES NOWDT
#FUSES HS
#FUSES NOPUT
#FUSES NOPROTECT

#use delay(clock=20000000)

#include <stdlib.h>


#INT_RB
void alarm_ISR(void)
{
int8 tpb;

tpb = input_b();

if (tpb & 0x01)
{
output_high(PIN_A5);
}
else output_low(PIN_A5);
}

void main(void)
{
set_tris_b(0b00000111);

enable_interrupts(INT_RB);
enable_interrupts(GLOBAL);
}

[PCM programmer]

Before you do anything else, add the NOLVP fuse. Without that fuse,
the PIC will lock-up if pin RB3 goes high.

Also, when you post code, enable the tickbox below the posting window
to disable HTML. Then you won't get lines like this:

[Ttelmah]

Read the data sheet.
What pins does the RB interrupt respond to?.
Does this include bit 0 of the port, which you are testing?.....
Also, remember the need to have something to stop the main running off the end, and sending the processor to sleep.

Best Wishes

[Will]

I'll check again, but I was sure it responded to A5-A7 on port A, all of B.

The code above doesn't seem to respond either and I forgot my serial cable back on campus...

[Ttelmah]

No, it responds to B4 to B7 _only_, you are testing B0....
Sction 12.10.3 in the data sheet.
On some chips, it responds to other bits, but not on the 877

Best Wishes