;----------------------------------------
;程序功能:代码转换，共实现五个功能
;1.小写转大写
;2.大写转小写
;3.二进制转十六进制
;4.十六进制转二进制
;5.十六进制转十进制
;-----------------------------------------
;*************************数据段开始
data segment
screen0 db 'please input the function you want to achieve',0ah,0dh
screen1 db '1.  xiao xie to da xie',0ah,0dh
screen2 db '2.  da xie to xiao xie',0ah,0dh
screen3 db '3.  B(2) to H(16)',0ah,0dh
screen4 db '4.  H(16) to B(2)',0ah,0dh
screen5 db '5.  H(16) to D(10)','$'
xtod db 'input a low letter:$'
dtox db 'input a capital letter:$'
BtoHh db 'input a number of binary(0000--1111):$'
HtoBh db 'input a number of hex(0-F):$'
HtoDh db 'input a number of hex(0--F):$'
buf0 db 17
buf1 db 0
buf db 17 dup('$')
num  db 0
data ends
;************************数据段结束
STAK    SEGMENT STACK
        DW 100 DUP (?)
STAK    ENDS
cr      macro
        push ax
        push dx
        mov dl,0ah
        mov ah,2
        int 21h
        mov dl,0dh
        mov ah,2
        int 21h
        pop dx
        pop ax
        endm
writes  macro a
        lea dx,a
        mov ah,9
        int 21h
        endm
write   macro c
        mov dl,c
        mov ah,2
        int 21h
        endm
;*******************代码段开始
code segment
     assume cs:code,ds:data
start: mov ax,data
       mov ds,ax
go: writes screen0
;*******************处理用户选择功能模块
      cr   
      mov ah,1
      int 21h
      cmp al,'q'
      jz done
      cmp al,31H
      jz R1
      cmp al,32H
      jz R2
      cmp al,33H
      jz R3
      cmp al,34H
      jz R4
      cmp al,35H
      jz R5
      jmp done
;******************跳转到小写转大写子程序
R1:   call smalltobig
      jmp go
;******************跳转到大写转小写子程序
R2:   call bigtosmall
      jmp go
;******************跳转到二进制转十六进制子程序
R3:   call BtoH
      jmp go
;******************跳转到十六进制转二进制子程序
R4:   call HtoB
      cr
      jmp go
;*****************跳转到十六进制转十进制子程序
R5:   call HtoD
      jmp go
;****************结束程序并返回
done: mov ah,4ch
      int 21h

;小写转大写子程序
smalltobig proc
           writes xtod
        cr
        call input
         cr
       sub al,20h
       write al
        cr
        ret
smalltobig endp

;大写转小写子程序
bigtosmall proc
           writes dtox
        cr
        call input
        cr
        add al,20h
        write al
        cr
        ret
bigtosmall endp

;二进制转十六进制子程序
BtoH       proc
        writes BtoHh
        cr
        mov bl,0
loopa:     mov     ah,1         
           int     21h   
        cmp al,13
           jz n
           cmp     al,30h   
           jb       loopa   
           cmp     al,31h   
           ja       loopa   
           and al,0fh
        add bl,al
        shl bl,1
        jmp loopa
n:         cr
         shr bl,1
        cmp bl,9
        jb nn
        add bl,7
nn:        add bl,30h
        write bl
           cr
        ret
BtoH endp

;十六进制转二进制子程序
HtoB proc
        writes HtoBh
        cr
        call input
        cr
        sub al,30h
        cmp al,9
        jna loop1
        sub al,7
loop1:     mov cl,4
        shl al,cl
        mov cl,4
       mov bl,al
gg:        shl bl,1
        jc lop
        mov dl,'0'
        jmp lop1
lop:        mov dl,'1'
lop1:        mov ah,2
        int 21h
        loop gg
        ret
HtoB       endp

;十六进制转十进制子程序
HtoD        proc
         writes HtoDh
        cr
        mov bx,0
tt:        call input
        cmp al,13
        jz y1
        cmp al,'9'
        jna y2
        sub al,7
y2:        sub al,30h
        mov cl,4
        mov ah,0
        add bx,ax
        shl bx,cl
        jmp tt
y1:       cr
        shr bx,cl
        mov ax,bx
        aaa
        add ax ,3030h
        mov bx,ax
        write bh
        write bl
        cr
        ret
HtoD       endp

;输入子程序
INPUT      PROC
           mov ah,1
           int 21h
           RET
INPUT   ENDP

code ends
       end start