Fixed typos

[MS-DOS.git] / v1.25 / source / HEX2BIN.ASM

; HEX2BIN  version 1.02
; Converts Intel hex format files to straight binary

FCB:    EQU     5CH
READ:   EQU     20
SETDMA: EQU     26
OPEN:   EQU     15
CLOSE:  EQU     16
CREATE: EQU     22
DELETE: EQU     19
BLKWRT: EQU     40
GETSEG: EQU     38
BUFSIZ: EQU     1024

        ORG     100H
        PUT     100H

HEX2BIN:
        MOV     DI,FCB+9
        CMP     B,[DI]," "
        JNZ     HAVEXT
        MOV     SI,HEX
        MOVB
        MOVW
HAVEXT:
;Get load offset (default is -100H)
        MOV     CL,4            ;Needed for shifts
        MOV     [OFFSET],-100H
        MOV     SI,FCB+11H      ;Scan second FCB for offset
        LODB
        CMP     AL," "          ;Check if offset present
        JZ      HAVOFF
        MOV     B,[SIGN],0      ;Assume positive sign for now
        CMP     AL,"+"
        JZ      GETOFF          ;Get a positive offset
        CMP     AL,"-"
        JNZ     GETOFF1         ;If not + or -, then not signed
        MOV     B,[SIGN],1      ;Flag as negative offset
GETOFF:
        LODB                    ;Eat sign
GETOFF1:
        CALL    HEXCHK          ;Check for valid hex character
        JC      HAVOFF          ;No offset if not valid
        XOR     BX,BX           ;Intialize offset sum to 0
CONVOFF:
        SHL     BX,CL           ;Multiply current sum by 16
        OR      BL,AL           ;Add in current hex digit
        LODB                    ;Get next digit
        CALL    HEXCHK          ;And convert it to binary
        JNC     CONVOFF         ;Loop until all hex digits read
        TEST    B,[SIGN],-1     ;Check if offset was to be negative
        JZ      SAVOFF
        NEG     BX
SAVOFF:
        MOV     [OFFSET],BX
HAVOFF:
        MOV     DX,STARTSEG
        MOV     AX,DS
        ADD     DX,AX           ;Compute load segment
        MOV     AH,GETSEG
        INT     33
        MOV     ES,DX
        SEG     ES
        MOV     CX,[6]          ;Get size of segment
        MOV     [SEGSIZ],CX
        XOR     AX,AX
        MOV     DI,AX
        MOV     BP,AX
        SHR     CX
        REP
        STOW                    ;Fill entire segment with zeros
        MOV     AH,OPEN
        MOV     DX,FCB
        INT     21H
        OR      AL,AL
        JNZ     NOFIL
        MOV     B,[FCB+32],0
        MOV     [FCB+14],BUFSIZ ;Set record size to buffer size
        MOV     DX,BUFFER
        MOV     AH,SETDMA
        INT     33
        MOV     AH,READ
        MOV     DX,FCB          ;All set up for sequential reads
        MOV     SI,BUFFER+BUFSIZ ;Flag input buffer as empty
READHEX:
        CALL    GETCH
        CMP     AL,":"          ;Search for : to start line
        JNZ     READHEX
        CALL    GETBYT          ;Get byte count
        MOV     CL,AL
        MOV     CH,0
        JCXZ    DONE
        CALL    GETBYT          ;Get high byte of load address
        MOV     BH,AL
        CALL    GETBYT          ;Get low byte of load address
        MOV     BL,AL
        ADD     BX,[OFFSET]     ;Add in offset
        MOV     DI,BX
        CALL    GETBYT          ;Throw away type byte
READLN:
        CMP     DI,[SEGSIZ]
        JAE     ADERR
        CALL    GETBYT          ;Get data byte
        STOB
        CMP     DI,BP           ;Check if this is the largest address so far
        JBE     HAVBIG
        MOV     BP,DI           ;Save new largest
HAVBIG:
        LOOP    READLN
        JP      READHEX

NOFIL:
        MOV     DX,NOFILE
QUIT:
        MOV     AH,9
        INT     21H
        INT     20H

ADERR:
        MOV     DX,ADDR
        JMP     SHOWERR

GETCH:
        CMP     SI,BUFFER+BUFSIZ
        JNZ     NOREAD
        INT     21H
        CMP     AL,1
        JZ      ERROR
        MOV     SI,BUFFER
NOREAD:
        LODB
        CMP     AL,1AH
        JZ      DONE
        RET

GETBYT:
        CALL    HEXDIG
        MOV     BL,AL
        CALL    HEXDIG
        SHL     BL
        SHL     BL
        SHL     BL
        SHL     BL
        OR      AL,BL
        RET

HEXCHK:
        SUB     AL,"0"
        JC      RET
        CMP     AL,10
        JC      CMCRET
        SUB     AL,"A"-"0"-10
        JC      RET
        CMP     AL,16
CMCRET:
        CMC
        RET

HEXDIG:
        CALL    GETCH
        CALL    HEXCHK
        JNC     RET
ERROR:
        MOV     DX,ERRMES
SHOWERR:
        MOV     AH,9
        INT     21H
DONE:
        MOV     [FCB+9],4F00H+"C"       ;"CO"
        MOV     B,[FCB+11],"M"
        MOV     DX,FCB
        MOV     AH,CREATE
        INT     21H
        OR      AL,AL
        JNZ     NOROOM
        XOR     AX,AX
        MOV     [FCB+33],AX
        MOV     [FCB+35],AX     ;Set RR field
        INC     AX
        MOV     [FCB+14],AX     ;Set record size
        XOR     DX,DX
        PUSH    DS
        PUSH    ES
        POP     DS              ;Get load segment
        MOV     AH,SETDMA
        INT     21H
        POP     DS
        MOV     CX,BP
        MOV     AH,BLKWRT
        MOV     DX,FCB
        INT     21H
        MOV     AH,CLOSE
        INT     21H
EXIT:
        INT     20H

NOROOM:
        MOV     DX,DIRFUL
        JMP     QUIT

HEX:    DB      "HEX"
ERRMES: DB      "Error in HEX file--conversion aborted$"
NOFILE: DB      "File not found$"
ADDR:   DB      "Address out of range--conversion aborted$"
DIRFUL: DB      "Disk directory full$"

OFFSET: DS      2
SEGSIZ: DS      2
SIGN:   DS      1
BUFFER: DS      BUFSIZ

START:
STARTSEG EQU    (START+15)/16
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