tailieunhanh - Cracker Handbook 1.0 part 67

Tham khảo tài liệu 'cracker handbook part 67', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 297D 0113 SHL DL CL It inserts zeros to the right 297D 0115 INT 21 Calls for Dos 297D 0117 SUB AL 30 Subtracts 30 from AL 297D 0119 CMP AL 09 Compares AL with 09 297D 011B JLE 011F Jumps if 011f direction 297D 011D SUB AL 07 Subtracts 07 from AL 297D 011F ADD DL AL Adds Al to DL 297D 0121 INT 20 Ends the Program This program can read two digit hex numbers Eleventh example -a100 297D 0100 CALL 0200 Calls for a procedure 297D 0103 INT 20 Ends the program -a200 297D 0200 PUSH DX Puts DX value on the stack 297D 0201 MOV AH 08 Function 8 297D 0203 INT 21 Calls for Dos 297D 0205 CMP AL 30 Compares AL with 30 297D 0207 JB 0203 Jumps if CF is activated towards 0203 direction 297D 0209 CMP AL 46 Compares AL with 46 297D 020B JA 0203 jumps if 0203 direction 297D 020D CMP AL 39 Compares AL with 39 297D 020F JA 021B Jumps if 021B direction 297D 0211 MOV AH 02 Function 2 writes on the screen 297D 0213 MOV DL AL Puts Al value on DL 297D 0215 INT 21 Calls for Dos 297D 0217 SUB AL 30 Subtracts 30 from AL 297D 0219 POP DX Takes DX value out of the stack 297D 021A RET Returns control to the main program 297D 021B CMP AL 41 Compares AL with 41 297D 021D JB 0203 Jumps if CF is activated towards 0203 direction 297D 021F MOV AH 02 Function 2 writes on the screen 297D 022 MOV DL AL Puts AL value on DL 297D 0223 INT 21 Calls for Dos 297D 0225 SUB AL 37 Subtracts 37 from AL 297D 0227 POP DX Takes DX value out of the stack 297D 0228 RET Returns control to the main program This program keeps reading characters until it receives one that can be converted to a hex number More Assembler programs examples using TASM program name of the program .model small .stack .code mov AH 1h Selects the 1 . function Int 21h reads character and return ASCII code to register AL mov DL AL moves the ASCII code to register DL sub DL 30h makes the operation minus 30h to convert 0-9 digit number cmp DL 9h compares if digit number it was between 0-9 jle digitl If it true gets the first number digit 4 .