i tried to get an interrupt at .1ms using dt-ints.

i used 16f877a at 4MHz and timer1 1:1 prescaler , want to toggle a led that connected to portb.7 to test interrupt.

timer1 pre-load value is 65437. The signal must be 5KHz , but it is about 2.4KHz.

The code is below.What am i missing or what is the mistake?

Code:
    INCLUDE "DT_INTS-14.bas"     ' Base Interrupt System
    INCLUDE "ReEnterPBP.bas"     ' Include if using PBP interrupts
    
    
    LED     VAR PORTB.7
    
    OUTPUT  LED
    
    ADCON1      = 7
    
    
    
    
    
    ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
    INT_Handler     TMR1_INT,       _TMR1_INT, PBP,  yes
    endm
    INT_CREATE               ; Creates the interrupt processor
    ENDASM

@ INT_ENABLE  TMR1_INT     ; enable Timer 1 interrupts


    T1CON = %00000101                ; Prescaler = 1, TMR1ON

    TMR1L = $9D         ; TMR1 = 65437
    TMR1H = $FF

    
    MAIN :
    
    PAUSE 50
   
GOTO MAIN
    
    
    TMR1_INT :
    
    TMR1L = $9D
    TMR1H = $FF
    
    TOGGLE LED
@ INT_RETURN