Hi;
        I have been playing with some pics on the simsticks off and on for the
last 6 months (mostly off due to time) but can't get them to run using a
Crystal of Resonator. I have had one running with a RC clock but putting it
back (with out changing the programing) to a crystal still did not work.

Please help

Thanks
Andrew

Simmstick items used
DT001           to program and test.
DT101   PIC16F84A-20, 20Mhz resonator, C2, R1,R2, R3
DT203           To display data

Software
MPLAB V5.20             To compile
Picall V0.07            To program

The code

        list      p=16F84A            ; list directive to define processor
        #include <p16F84A.inc>        ; processor specific variable definitions

        __CONFIG   _CP_OFF & _WDT_OFF & _PWRTE_ON & _XT_OSC

;***** VARIABLE DEFINITIONS
w_temp        EQU     0x0C        ; variable used for context saving
status_temp   EQU     0x0D        ; variable used for context saving
ram1          EQU     0x0E
ram2          EQU     0x0F
xx            EQU     0x00
                ORG     0x000             ; processor reset vector
                goto    main              ; go to beginning of program


                ORG     0x004             ; interrupt vector location
                movwf   w_temp            ; save off current W register contents
                movf    STATUS,w          ; move status register into W register
                movwf   status_temp       ; save off contents of STATUS register

                movf    status_temp,w     ; retrieve copy of STATUS register
                movwf   STATUS            ; restore pre-isr STATUS register contents
                swapf   w_temp,f
                swapf   w_temp,w          ; restore pre-isr W register contents
                retfie                    ; return from interrupt

main

                bsf     STATUS,5
                clrf    TRISA
                clrf    TRISB
                bcf     STATUS,5
                movlw   h'00'
                movwf   PORTB
                movwf   PORTA
                bcf     STATUS,2
addone:         incf    PORTB,f
                movf    PORTA,xx
                incf    xx,f
                movwf   PORTA
                movlw   0
                movwf   ram2
                goto    addone
                movlw   0
                movwf   ram1
delay:          incf    ram1,f
                btfss   STATUS,2
                goto    delay
delay2:         incf    ram2,f
                btfss   STATUS,2
                goto    delay
                goto    addone

                END                     ; directive 'end of program'

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