#define CALCULATOR TI89
#include "ti89.inc"

    .org userMem-2
    .db t2ByteTok,tAsmCmp

start:
    ; Save registers we'll use
    move.l  a5,-(sp)
    move.l  a6,-(sp)
    
    ; Clear screen
    move.w  #ClrScr,-(sp)
    trap    #1
    addq.l  #2,sp
    
    ; Get initial timer value
    move.l  #$600000,a5    ; Timer control register address
    move.l  (a5),d0        ; Read initial value
    
    ; Perform timing loop
    move.l  #1000000,d7    ; Number of iterations
timing_loop:
    nop                    ; Single cycle operation
    dbf     d7,timing_loop
    
    ; Get final timer value
    move.l  (a5),d1        ; Read final value
    
    ; Calculate elapsed cycles
    sub.l   d0,d1          ; d1 now contains elapsed timer ticks
    
    ; Calculate MHz (timer runs at 32768Hz)
    move.l  #32768,d2      ; Timer frequency
    divu.w  d2,d1          ; Convert to seconds
    
    ; Display result
    pea     result_str
    move.w  #PutS,-(sp)
    trap    #1
    addq.l  #6,sp
    
    ; Restore registers and exit
    move.l  (sp)+,a6
    move.l  (sp)+,a5
    rts

result_str:
    .ascii  "CPU Speed (approx): "
    .db     0

    .end    start