; Freeware, Program: hello51.asm
                   ; 
                   ; 
                   ; (1) On J51 simulator set "CPU" to j51.intel.P8051
                   ; (2) File --> Load --> hello51.hex
                   ; (3) Go
                   ; (7) Peripheral output should say: Hello, World and Goodbye
                   ; (5) Stop
                   ; (6) File --> Exit
                   ;
                   ; (7) In order to assmble this program: as31 -l hello51.asm
                   ; will output a listing file and a intel hex file: hello51.l
                   ;
0000:                       .org  0h 
                   start:
0000: 75 89 20              mov   TMOD, #20h ; set timer 1 for auto reload 
0003: 75 88 41              mov   TCON, #41h ; run counter 1 edge trig
0006: 75 8D FD              mov   TH1,  #0FDh ; 9600 baud
0009: 75 98 50              mov   SCON,#50h ; 8-bit data mode 1 
                   
000C: 90 00 30              mov   dptr,#msg1
000F: 12 00 1A              lcall puts
0012: 90 00 3E              mov   dptr,#msg2
0015: 12 00 1A              lcall puts
0018: 80 FE        idle:    sjmp  idle
                   
                   puts:
001A: E4                   clr   a
001B: 93                    movc  a,@a+dptr
001C: 60 11                 jz    putret
001E: C2 99                 clr   TI
0020: F5 99                 mov   SBUF, A
0022: 30 99 FD     puts1:   jnb   TI,puts1
0025: A3                    inc   dptr
0026: 80 F2                 sjmp  puts
                   
                   putchar:
0028: C2 99                 clr   TI
002A: F5 99                 mov   SBUF, A
                   putchar1:
002C: 30 99 FD              jnb   TI, putchar1
002F: 22           putret:ret
                   
                   
0030: 48 65 6C 6C 
      6F 2C 20     msg1:    .byte   'H','e','l','l','o',',',' '
0037: 57 6F 72 6C 
      64 0A 00              .byte   'W','o','r','l','d',0x0a, 0
                   
003E: 47 6F 6F 64 
      62 79 65 0A 
      00           msg2:   .byte   'G','o','o','d','b','y','e',0x0a,0
                   
0047:                       .end