DT_INTS-14  (Assembly Language Interrupts)

Here's another example of a Blinky Light program using TMR1 with an Assembly Language Interrupt handler.
Note that the INT_Handler's Type is ASM, and the Label does not have an underscore before it.
Code: 
LED1   VAR  PORTD.0
LOW  LED1                    ; Set to Output Low

INCLUDE "DT_INTS-14.bas"     ; Base Interrupt System

ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler   TMR1_INT,   ToggleLED1,   ASM,  yes
    endm
    INT_CREATE               ; Creates the interrupt processor

    INT_ENABLE  TMR1_INT     ; Enable Timer 1 Interrupts  
ENDASM

T1CON = $31                  ; Prescaler = 8, TMR1ON

Main:
    PAUSE 1
GOTO Main

'---[TMR1_INT - interrupt handler]------------------------------------------
ASM
ToggleLED1
    btfsc  _LED1
    goto   $+3
    bsf    _LED1
    goto   $+2
    bcf    _LED1
    INT_RETURN
ENDASM
Code Size = 104 Words