TITLE        Coded by Elk, 2002

.186

EXTRN        readff:FAR, check:FAR, writeinf:FAR

STCK         SEGMENT STACK
             DB 256 DUP(?)
STCK         ENDS

DATA         SEGMENT
             hexdata    DB 5 DUP(?)
             hexdatanum DD ?
             filehandle DW ?
             hexword    DW ?
             in_str     DB 13,0,13 DUP(' ')
             infile     DB 13 DUP(0)
             error      DB 'Error!$'
DATA         ENDS

CODE         SEGMENT 'CODE'
             ASSUME CS:CODE, DS:DATA

START:       MOV AX, DATA
             MOV DS, AX

             LEA DX, in_str
             MOV AH, 0Ah
             INT 21h

             MOV SI, WORD PTR in_str[1]
             XOR DI, DI
             MOV CL, 8
             SHL SI, CL
             SHR SI, CL
re_snd:      MOV AL, in_str[DI+2]
             MOV infile[DI], AL
             DEC SI
             INC DI
             TEST SI, SI
             JNZ re_snd

             PUSH OFFSET infile
             PUSH OFFSET filehandle
             PUSH OFFSET hexdata
             CALL readff

             XOR AX, AX
             MOV DI, 4
next:        MOV CL, 4
             SHL AX, CL
             XOR BX, BX
             MOV BL, hexdata[DI]
             CMP BX, 57
             JG abc
             SUB BX, 48
             JMP in_ax
abc:         SUB BX, 55
in_ax:       ADD AX, BX
             DEC DI
             TEST DI, DI
             JZ ouut
             JMP next
ouut:        XOR DX, DX
             MOV DL, hexdata[DI]
             CMP DX, 57
             JG abc_dx
             SUB DX, 48
             JMP in_dx
abc_dx:      SUB DX, 55
in_dx:       MOV WORD PTR hexdatanum, AX
             LEA DI, hexdatanum
             MOV [DI+2], DX

             PUSH WORD PTR hexdatanum
             PUSH WORD PTR hexdatanum+2
             PUSH hexword
             CALL check

             TEST AX, AX
             JZ no_error


             MOV AH, 2
             MOV DX, 13
             INT 21h
             MOV DX, 10
             INT 21h

             MOV DX, OFFSET error
             MOV AH, 9
             INT 21h
             JMP quit

no_error:    POP BX
             MOV hexword, BX
             MOV hexdata[1], BH
             MOV hexdata[0], BL

             PUSH OFFSET infile
             PUSH OFFSET filehandle
             PUSH OFFSET hexdata
             CALL writeinf

quit:        MOV AX, 4C00h
             INT 21h

CODE         ENDS

             END START