问题
I know that every 4 bit in BCD is one digit in decimal, but I have a problem, for example when I want to print a BCD value stored in CH I do this :
add ch, 30h
but, when the value is 12, it prints "C", I want to print "12". How can I do operations on 4 bit of data?
回答1:
mov al,ch ; if ch has 12h
aam ; ax will now be 0102h
or ax,3030h ; converting into ascii - ax will now become 3132h
; you can now print the value in ax
mov cx,ax
mov dl,ch ; to print on screen
mov ah,02h
int 21h
mov dl,cl
int 21h
ret
8086 AAM Instruction
8086 INT 21h function to print a character
来源：https://stackoverflow.com/questions/37024912/bcd-to-ascii-conversion