Compilation of one-day learning (13)--16 binary display binary

This problem algorithm describes:

hexadecimal conversion to binary is the expansion of each bit:

such as 1234H expansion: 0001 0010 0011 0100

1.bx:0000 0000 0000 0000

2. Enter a legal number to convert to 0000b~1001b or to: 1010b~1111b

3. Merge with BX

4.BX shift left four bit

; receives a four-bit 16 binary number from the keyboard and displays its equivalent binary number on the terminal

DATAS SEGMENT

STR DB 0dh,0ah, ' $ '

DATAS ENDS

CODES SEGMENT

MAIN PROC Far

Assume Cs:codes, Ds:datas

START:

PUSH DS

SUB Ax, Ax

PUSH AX

MOV AX, DATAS

MOV DS, AX

;---------------------------------------------------------

MOV ch,4; hex number of four digits

MOV cl,4; shift times

MOV bx,0; store 16-bit binary

INPUT:

SHL BX, CL; move left four bits

MOV ah,01h; Enter the number of 0~9,a~f,a~f

INT 21H

CMP AL, ' 0 '

JB INPUT

CMP AL, ' F '

JA INPUT

CMP AL, ' 9 '

Jbe NUM; The number entered is 0~9

CMP AL, ' @ '

Jbe INPUT

CMP AL, ' F '

Jbe Convert1; The number of inputs is a~f

CMP AL, ' a '

JB INPUT

CMP AL, ' F '

Jbe Convert2; The number of inputs is a~f

Num:

and al,0fh; 0000b~1001b

JMP BINARY

Convert1:

and AL,0FH

ADD AL, 9

JMP BINARY

Convert2:

SUB al,20h; lowercase to uppercase in action with

and al,0fh; Convert to: 1010b~1111b

ADD AL, 9

JMP BINARY

BINARY:

or BL, AL; combine the number of keyboard inputs

DEC CH

JNZ INPUT

DISPN:

MOV CX, 16; Converts a 16-bit binary number one bit to ASCII code display

LEA Dx,str

MOV ah,09h

INT 21H

DISP:

MOV DL, 0

ROL BX, 1; Note these two instructions

RCL DL, 1

OR DL, 30H

MOV AH, 2;

INT 21H

LOOP DISP

Ret

MAIN ENDP

CODES ENDS

END START

Summary:

1. A new idea: The shift operation, the BX16 bits hold 4 hexadecimal 0000 respectively

2.AND al,0fh; Convert to: 1010b~1111b or 0000b~1001b or

hexadecimal digits and operations into the corresponding binary

3.OR

4. ROL BX, 1; cyclic left shift

RCL DL, 1; with carry loop left shift