;這是一個(gè)使用單片機(jī)的I/O口線控制微型打印機(jī)的實(shí)用程序.
    ;微型打印機(jī)為: 40針內(nèi)含漢字庫(kù)的并行接口點(diǎn)陣打印機(jī)
    ;將微打的D0-D7接焊盤 P0.0--P0.7,將微打的/STB,BUSY接焊盤的P2.0-P2.1.
    ;將P0.0-P0.7,P2.1-P2.0跳帽置焊盤位.
   
----------- IT'S FOR S51E --------------------------
    dat_port   equ    p0
    stb        bit    p2.0
    busy       bit    p2.1

    org  000h
    JMP  START
    ORG  100H
;----------------------------------------
start:mov   P0,#0ffh          ;初始化MCU端口
      mov   P1,#0ffh
      mov   P3,#0ffh
      MOV   P2,#0F0H
      MOV   A,#00H           ;初始化寄存器
      MOV   PSW,#00H
      MOV   IE,#00H
      MOV   SP,#30H
      
main:         acall ho1o          ;調(diào)用一級(jí)庫(kù)打印            
              acall   lopo        ;打印"#-#-"20個(gè)
              acall   hoho        ;換一行       
              mov A,#00H
              MOV R6,#00H
              MOV DPTR,#TAB1
        lop1: MOV A,R6            ;打印"1234567890ABCDEFGHIJKLMNOP
              movc a,@a+dptr      ;QRSTUVWXYZ    OK!"字符
              acall sozo
              inc r6
              CjnE r6,#46,lop1
              acall hoco          ;換行
              acall lopo          ;再打印"#-#-"20個(gè)
              acall hoho          ;換行
              acall hogo          ;設(shè)定打印漢字方式
              mov A,#00H
              MOV R6,#00H
              MOV DPTR,#TAB2
        lop2: MOV A,R6            ;打印"歡迎使用南京偉煌S51在線開發(fā)板！"
              movc a,@a+dptr
              acall sozo
              inc r6
              CjnE r6,#34,lop2 
              acall hoco          ;回車換行
              acall hoco  
              jmp $               ;演示結(jié)束！


        ho1o:mov a,#1bh  ;調(diào)用一級(jí)庫(kù)
             acall sozo
             mov a,#38h
             acall sozo
             mov a,#00h
             acall sozo
             acall hoho
             ret

     hoho:mov a,#0ah     ;換行
           acall sozo
           ret

      hoco:mov a,#0dh    ;回車換行
           acall sozo
           ret
     hogo:mov a,#1bh     ;選定16*16漢字點(diǎn)陣
          acall sozo
          mov a,#38h
          acall sozo
          mov a,#00h
          acall sozo
          ret  
    
      lopo: mov  r7,#15
      l1po: mov a,#23h    ;"#"
            acall  sozo   
            mov a,#2Dh    ;"-"
            acall sozo    ;
            djnz r7,l1po
            ret
           
 sozo:      push dph      ;打印單字符或傳輸指令
            push dpl
            jb   busy,$   ;/busy ?
            mov  dat_port,a
            clr   stb
            nop
            setb  stb
            pop dpl
            pop dph
            ret        

   ;ORG 800H  ;單字符字碼表（單字節(jié)）
  TAB1: db 31h,32h,33h,34h,35h,36h,37h,38h,39h,30h
   db 41h,42h,43h,44h,45h,46h,47h,48h,49h,4ah
   db 4bh,4ch,4dh,4eh,4fh,51h,52h,53h,54h,0dh
   db 55h,56h,57h,58h,59h,5ah,20h,20h,20h,20h
   db 2dh,2dh,4fh,4bh,20h,21h
   ;org 900h  ;漢字字碼表（雙字節(jié)）
 TAB2:  db 0bbh,0b6h,0d3h,0adh,0cah,0b9h,0d3h,0c3h ;"歡迎使用"
   db 0c4h,0cfh,0beh,0a9h,0b0h,0aeh,0cbh,0bch ;"南京偉煌"
   db 0A3h,0b5h,0a3h,0b1h,0a3h,0c2h   ;"S51"
   db 0b8h,0dfh,0bch,0b6h,0d3h,0c3h  ;"在線開"
   db 0bbh,0a7h,0b0h,0e5h,0a3h,0a1h  ;"發(fā)板!"
	end