/* echo.asm
 * CMPE 001, Fall 2004
 * ver 1.0 /cb,rph,scp
 * This is a simple program to introduce the 68HC11 Microkit
 */

#include <v2_18g3.asm>
   .sect .data
   
program: .asciz   "Echo v1.01"
prompt:  .asciz   ">"

   .sect .text

/* Your program starts here indicated by the label "main:".
 * After startup code in v2_18g3.asm is done, we jumps to this
 * label and continue running (see Motorola Ref. Manual 6-12 for instruction set). */

main:
   // One time initialization code:
   // Task 1: Write to the terminal the program we're running and clear the LCD
   ldx   #program    // address pointer of signon string in memory
   jsr   OUTSTRING   // write a null-terminated string to the serial port
   
   ldaa  #1          // ACCA <-- 1; this is a command code for the LCD
   jsr   LCD_CMD     // clear LCD


   ldx   #prompt     // address of prompt
   jsr   OUTSTRING   // write prompt out to the serial port
   jsr   OUTCRLF     // print out a carriage return


echo_loop:
   /* Get a character and put it in accumulator A (ACCA), then print it to the LCD.
    * The serial port will output will go to your computer
    * monitor.  Serial port input will come from the keyboard.
    * There is no local echo; you will not see your own input. 
    */
   jsr   GETCHAR     // getchar returns in ACCA
   jsr   OUTCHAR     // write ACCA to screen
   jsr   LCD_CHAR    // Write to the LCD as well
   coma              // ACCA <-- not ACCA; invert the accumulator A for the LEDs
   staa  LEDS
   jmp   echo_loop