Initial commit
Initial import of the transcribed source code from Tim Paterson's DOS listings. Co-authored-by: RichCini <rich.cini@gmail.com>
This commit is contained in:
Yufeng Gao
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Load Diff
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Load Diff
@@ -0,0 +1,560 @@
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; CHKDSK Version 1.0 03/10/81
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; Verifies and repairs 86-DOS disk directory.
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SETDRV: EQU 14
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GETDRV: EQU 25
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GETMAP: EQU 27
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OPEN: EQU 15
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CLOSE: EQU 16
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DELETE: EQU 19
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SETDMA: EQU 26
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SRCHFST:EQU 17
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SRCHNXT:EQU 18
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OUTCH: EQU 2
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BLKWRT: EQU 40
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PRINTBUF:EQU 9
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ORG 100H
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PUT 100H
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CHKDSK:
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MOV SP,STACK
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MOV AH,GETDRV
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INT 21H
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MOV [CURDRV],AL
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MOV DL,[5CH]
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OR DL,DL
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JZ DRVSET
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MOV AH,SETDRV
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DEC DL
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INT 21H
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CMP AL,DL
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JA DRVSET
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MOV DX,BADDRV
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ERROR:
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MOV AH,PRINTBUF
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INT 33
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INT 32
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BADDSK:
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MOV AX,CS
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MOV DS,AX
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MOV AH,SETDRV
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MOV DL,[CURDRV]
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INT 33
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MOV DX,DIRBAD
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JP ERROR
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DRVSET:
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MOV B,[WRKDRV],DL ;Save drive indicator
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MOV AH,GETMAP
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INT 21H
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CMP B,[BX],0FEH ;Check for initialized disk
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JNE BADDSK
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PUSH DS
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PUSH ES
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POP DS
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MOV [DSKSIZ],DX ;Number of allocation units
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MOV [SECSIZ],CX ;Size of physical sector
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MOV AH,0
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MOV [CLUSSIZ],AX ;Sectors per cluster
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MOV CX,DX
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MOV DI,MAP
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XOR AX,AX
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REP
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STOW ;Zero out allocation map
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MOV CX,AX
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MOV [ALLOC],AX ;Count of allocation units used
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MOV [FILECNT],AX ;Number of files found
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MOV [DELCNT],AX ;Number of files deleted due to error
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MOV BP,DI
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MOV [NAMTAB],BP ;First address of file list
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MOV DX,DI
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MOV AH,SETDMA
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INT 21H
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MOV AH,SRCHFST
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MOV DX,ALLFILE
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INT 21H
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INC AL
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POP ES ;ES:BX point to FAT
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JNZ GETFILES
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JMP COMPMAP
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GETFILES:
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INC CX ;Count number of files
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ADD DI,44 ;Separate in file in list by 44 bytes
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MOV DX,DI
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MOV AH,SETDMA
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INT 21H
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MOV AH,SRCHNXT
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MOV DX,ALLFILE
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INT 21H
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INC AL
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JNZ GETFILES ;Loop until all files are in list
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MOV [FILECNT],CX
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MOV CX,1 ;File number (position in list)
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MOV DX,[DSKSIZ]
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INC DX ;Maximum cluster number
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MOV [MAXCLUS],DX
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ADD BP,34 ;Point to "first cluster" entry
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EACHFIL:
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XOR AX,AX ;No. of clusters in file
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MOV SI,[BP] ;First cluster of file
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CMP SI,[MAXCLUS] ;Make sure it's legal
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MOV DI,BADDIR
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JA BADFIRST
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OR SI,SI ;Check for zero-length file
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JZ HAVENDJ
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SCANFAT:
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MOV DI,CX
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SHL SI
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XCHG DI,[SI+MAP-4] ;Xchange current map entry with file no.
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SHR SI
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OR DI,DI ;Should be zero for unallocated cluster
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JNZ CROSSLINK
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INC AX ;Count cluster as part of this file
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CALL UNPACK
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JZ FORCEND ;Make sure cluster knows it's allocated
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CMP DI,0FF8H ;Bigger than this means End of File
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HAVENDJ:JAE HAVEND
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CMP DI,[MAXCLUS] ;Make sure it's a legal value
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JA FORCEND
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MOV SI,DI
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JP SCANFAT ;Visit each cluster allocated to file
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BADFIRST:
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PUSH AX ;Because FILERR will pop it later
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MOV AX,CX
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MOV DX,44
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DEC AX
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MUL AX,DX ;Get position in file name table
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MOV DX,AX
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ADD DX,[NAMTAB]
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MOV AH,DELETE
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INT 21H
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OR AL,AL ;SEE IF WE HAVE A VALID DIRECTORY
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JZ DISKOK
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JMP BADDSK
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DISKOK:
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INC [DELCNT] ;Count one deleted file
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MOV DX,BADDIR
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JP FILERR
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CROSSLINK:
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MOV DX,LINKED
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PUSH AX
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MOV AH,PRINTBUF
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INT 21H
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MOV AX,DI
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CALL PRINTNAM
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MOV DX,FILE2
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MOV AH,PRINTBUF
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INT 33
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MOV AX,CX
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CALL PRINTNAM
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MOV DX,CRLF
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MOV AH,PRINTBUF
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INT 33
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POP AX
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ADD [ALLOC],AX
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JMP SIZSET1
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FORCEND:
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; Come here if a cluster allocated to a file contained an illegal
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; link--either a zero (meaning unallocated), or a value larger than
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; the maximum cluster number, but not End of File. Put an End of File
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; mark there so the FAT will at least be well-formed.
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MOV DX,0FFFH
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CALL PACK
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MOV DX,BADCLUS
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PUSH AX
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FILERR:
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MOV AH,PRINTBUF
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INT 21H
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MOV AX,CX
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CALL PRINTNAM
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MOV DX,CRLF
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MOV AH,PRINTBUF
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INT 21H
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POP AX
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HAVEND:
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ADD [ALLOC],AX ;Total up allocated clusters
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MOV SI,AX
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MOV AX,[BP+2]
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MOV DX,[BP+4] ;AX:DX now have file length
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PUSH CX
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MOV CX,[CLUSSIZ]
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DEC CX
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ADD AX,CX
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ADC DX,0
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INC CX
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SCALE:
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SHR CX
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JC SCALED
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SHR DX
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RCR AX
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JP SCALE
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SCALED:
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DIV AX,[SECSIZ]
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OR DX,DX
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JZ HAVSIZ
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INC AX
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HAVSIZ:
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CMP AX,SI ;See if file size corresponds with allocation
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JZ SIZSET
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XOR DI,DI
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MOV CX,[CLUSSIZ]
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CALL UNSCALE
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MOV [BP+6],SI
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MOV [BP+8],DI
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MOV DX,BP
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SUB DX,34
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MOV AH,OPEN
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INT 21H
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OR AL,AL
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JZ DISKOK2
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JMP BADDSK
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DISKOK2:
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MOV AX,[SECSIZ]
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MOV [BP-27+14],AX ;Make record size=sector size
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MOV CX,0
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MOV AH,BLKWRT
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INT 21H
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MOV AH,CLOSE ;Write back corrected directory entry
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INT 21H
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MOV AH,GETMAP
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PUSH DS
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INT 33 ;Make sure FAT dirty bit is still set
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POP DS
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MOV DX,BADSIZ
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MOV AH,PRINTBUF
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INT 21H
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POP AX
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PUSH AX
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CALL PRINTNAM
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MOV DX,CRLF
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MOV AH,PRINTBUF
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INT 21H
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SIZSET:
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POP CX
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SIZSET1:
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ADD BP,44 ;Scan next file
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INC CX
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CMP CX,[FILECNT]
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JA COMPMAP
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JMP EACHFIL
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; Now compare the allocation map we have made with the FAT. Any
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; clusters not allocated in the map will be released.
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COMPMAP:
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XOR AX,AX ;Keep count of clusters released
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MOV BP,MAP
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MOV SI,2 ;First usable cluster number
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MOV CX,[DSKSIZ]
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RELCLUS:
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TEST [BP],-1 ;Allocated in our map?
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JNZ NXTCLUS ;If so, skip to next
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CALL UNPACK
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JZ NXTCLUS ;If not allocated, skip to next
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XOR DX,DX
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CALL PACK ;Change to "Free" status
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INC AX ;Count clusters released
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NXTCLUS:
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INC BP
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INC BP
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INC SI
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LOOP RELCLUS
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OR AX,AX ;Any clusters released?
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JZ REPORT ;If not, do final report
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MOV BX,FREED
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CALL DISPCLUS
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REPORT:
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; Make status report. Include no. of files, total disk space,
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; free space on disk, total memory, and free memory.
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SEG CS
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MOV DL,[CURDRV]
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MOV AH,SETDRV
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INT 21H
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MOV SI,[FILECNT]
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SUB SI,[DELCNT]
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XOR DI,DI
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MOV BX,NUMFIL
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CALL DISP32BITS
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MOV AX,[DSKSIZ]
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MOV BX,DSKSPC
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CALL DISPCLUS
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MOV AX,[DSKSIZ]
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SUB AX,[ALLOC]
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MOV BX,FRESPC
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CALL DISPCLUS
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MOV AX,[2]
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MOV DX,16
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MUL AX,DX
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MOV SI,AX
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MOV DI,DX
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MOV BX,TOTMEM
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CALL DISP32BITS
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MOV AX,[2]
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MOV DX,CS
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SUB AX,DX
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MOV DX,16
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MUL AX,DX
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MOV SI,AX
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MOV DI,DX
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MOV BX,FREMEM
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CALL DISP32BITS
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CALL WRTFRC ;Force all writes and handle write
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;protect violation
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INT 20H ;All done
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WRTFRC: ;********************************************************
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; This code forces all writes by performing a disk
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; reset (function 13). When the attempt to write
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; the allocation table fails in the case of a write-
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; protected diskette, this logic determines if the
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; allocation table had changed and if no changes were
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; made a normal termination will be forced
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;*********************************************************
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MOV AX,DS
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PUSH DS ;Must first intercept INT 24H
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MOV ES,AX
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XOR AX,AX
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MOV DS,AX
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MOV SI,90H
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MOV DI,INT24 ;will move vector to local address
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MOV CX,2
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CLD ;So move will increment
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REP
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MOVW ;Vector now locally stored
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MOV AL,24H ;
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MOV AH,37
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MOV DX,WRTPRT ;
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POP DS ;Get local segment
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INT 21H ;Interrupt vector now set
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MOV AH,13
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INT 21H
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PUSH ES ;Will now reset INT 24H vector
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XOR AX,AX
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MOV ES,AX
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CLD
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MOV DI,90H
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MOV SI,INT24
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MOV CX,2
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REP
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MOVW
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POP ES
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RET
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WRTPRT: ;*********************************************************
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; This logic is designed to handle the case where
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; CHKDSK found no problems and upon rewriting the
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; allocation table (by the DOS) the disk was write-
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; protected and an error thus occured. With no problems
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; this code will cause normal termination, otherwise
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; normal error handling will occur.
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;*********************************************************
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EI ;Run with interrupts live
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AND DI,0FFH ;See if write-protect
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JNZ WRT100 ;Do normal error handling
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CMP AH,3 ;File allocation write?
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JNZ WRT100 ;If not do normal handling
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SEG CS
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CMP [WRKDRV],AL ;Correct drive?
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JNZ WRT100 ;
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SEG CS
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CMP B,[CHGCLS],1 ;Legitimate change?
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JZ WRT100 ;If so do normal handling
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XOR AL,AL ;Ignore the error
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IRET
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WRT100: SEG CS
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JMP L,[INT24] ;Normal error handling
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UNPACK:
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MOV DI,SI
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SHR DI
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ADD DI,SI
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SEG ES
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MOV DI,[DI+BX]
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TEST SI,1
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JZ HAVCLUS
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SHR DI
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SHR DI
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SHR DI
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SHR DI
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HAVCLUS:
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AND DI,0FFFH
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RET
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PACK:
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;*************************************************************
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; ES:BX POINTER TO THE BASE OF THE ALLOCATION TABLE
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; SI CLUSTER NUMBER TO BE PACKED
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; DX POINTER TO BE PLACED IN CLUSTER (SI)
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;*************************************************************
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MOV B,[CHGCLS],1 ;INDICATE CLUSTER CHANGED
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PUSH SI
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MOV DI,SI
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SHR SI
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ADD SI,BX
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ADD SI,DI
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SHR DI
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SEG ES
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MOV DI,[SI]
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JNC ALIGNED
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SHL DX
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SHL DX
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SHL DX
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SHL DX
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AND DI,0FH
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JP PACKIN
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ALIGNED:
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AND DI,0F000H
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PACKIN:
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OR DI,DX
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SEG ES
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MOV [SI],DI
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POP SI
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RET
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UNSCALE:
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SHR CX
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JC RET
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SHL SI
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RCL DI
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JP UNSCALE
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DISPCLUS:
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MUL AX,[SECSIZ]
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MOV CX,[CLUSSIZ]
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MOV SI,AX
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MOV DI,DX
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CALL UNSCALE
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DISP32BITS:
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PUSH BX
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XOR AX,AX
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MOV BX,AX
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MOV BP,AX
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MOV CX,32
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CONVLP:
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SHL SI
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RCL DI
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XCHG AX,BP
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CALL CONVWRD
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XCHG AX,BP
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XCHG AX,BX
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CALL CONVWRD
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XCHG AX,BX
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ADC AL,0
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LOOP CONVLP
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; Conversion complete. Print 10-digit number with 2 leading blanks.
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MOV CX,1B10H
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CALL OUTWORD
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MOV AX,BX
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CALL OUTWORD
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MOV AX,BP
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CALL OUTWORD
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POP DX
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MOV AH,PRINTBUF
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INT 21H
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RET
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OUTWORD:
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PUSH AX
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MOV DL,AH
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CALL OUTBYTE
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POP DX
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OUTBYTE:
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MOV DH,DL
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SHR DL
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SHR DL
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SHR DL
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SHR DL
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CALL DIGIT
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MOV DL,DH
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DIGIT:
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AND DL,0FH
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JZ BLANKZER
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MOV CL,0
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BLANKZER:
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DEC CH
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AND CL,CH
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OR DL,30H
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SUB DL,CL
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MOV AH,OUTCH
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INT 21H
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RET
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||||
|
||||
CONVWRD:
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||||
ADC AL,AL
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DAA
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XCHG AL,AH
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ADC AL,AL
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DAA
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XCHG AL,AH
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RET
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||||
|
||||
PRINTNAM:
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PUSH CX
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DEC AX
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MOV CX,44
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MUL AX,CX
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MOV SI,AX
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ADD SI,[NAMTAB]
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ADD SI,8
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MOV CX,8
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MOV AH,OUTCH
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CALL PRINTCNT
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MOV DL," "
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INT 21H
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MOV CL,3
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CALL PRINTCNT
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POP CX
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RET
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PRINTCNT:
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LODB
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MOV DL,AL
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INT 21H
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LOOP PRINTCNT
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RET
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ALLFILE:DB -1,0,0,0,0,0,6 ;Extended FCB
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DB 0,"???????????"
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DS 25
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||||
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FILE2: DB " and $"
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BADDRV: DB "Invalid drive specification$"
|
||||
BADCLUS:DB "Allocation error for file $"
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BADDIR: DB "Directory error-file : $"
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LINKED: DB "Files cross-linked: "
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DB 13,10
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DB " $"
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BADSIZ: DB "File size error for file $"
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||||
DIRBAD: DB "Diskette not initialized $"
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||||
FREED: DB " bytes disk space freed",13,10,13,10,"$"
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NUMFIL: DB " disk files",13,10,"$"
|
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DSKSPC: DB " bytes total disk space",13,10,"$"
|
||||
FRESPC: DB " bytes remain available",13,10,13,10,"$"
|
||||
TOTMEM: DB " bytes total memory",13,10,"$"
|
||||
FREMEM: DB " bytes free"
|
||||
CRLF: DB 13,10,"$"
|
||||
|
||||
DSKSIZ: DS 2
|
||||
SECSIZ: DS 2
|
||||
CLUSSIZ:DS 2
|
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CHGCLS: DB 0 ;IF RESET TO 1-ALLOCATION TABLE UPDATED
|
||||
WRKDRV: DB 0
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||||
INT24: DS 4
|
||||
FILECNT:DS 2
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||||
NAMTAB: DS 2
|
||||
ALLOC: DS 2
|
||||
MAXCLUS:DS 2
|
||||
DELCNT: DS 2
|
||||
CURDRV: DS 1
|
||||
DS 100H
|
||||
STACK:
|
||||
|
||||
MAP:
|
||||
|
||||
@@ -0,0 +1,611 @@
|
||||
; CHKDSK Version 1.0 03/10/81
|
||||
|
||||
; Verifies and repairs 86-DOS disk directory.
|
||||
|
||||
SETDRV: EQU 14
|
||||
GETDRV: EQU 25
|
||||
GETMAP: EQU 27
|
||||
OPEN: EQU 15
|
||||
CLOSE: EQU 16
|
||||
DELETE: EQU 19
|
||||
SETDMA: EQU 26
|
||||
SRCHFST:EQU 17
|
||||
SRCHNXT:EQU 18
|
||||
OUTCH: EQU 2
|
||||
BLKWRT: EQU 40
|
||||
PRINTBUF:EQU 9
|
||||
|
||||
ORG 100H
|
||||
PUT 100H
|
||||
|
||||
CHKDSK:
|
||||
MOV SP,STACK
|
||||
OR AL,AL ;SEE IF INVALID DRIVE SPECIFIED
|
||||
JNZ DRVERR ;IF SO JUST EXIT
|
||||
CMP B,[5DH],20H ;MAKE SURE TYPED CORRECTLY
|
||||
JNZ PRMERR ;IF NOT PARAMETER ERROR
|
||||
MOV AH,GETDRV
|
||||
INT 21H
|
||||
MOV [CURDRV],AL
|
||||
MOV DL,[5CH]
|
||||
OR DL,DL
|
||||
JZ DRVMOV
|
||||
MOV AH,SETDRV
|
||||
DEC DL
|
||||
INT 21H
|
||||
CMP AL,DL
|
||||
JA DRVSET
|
||||
DRVERR: MOV DX,BADDRV
|
||||
ERROR:
|
||||
MOV AH,PRINTBUF
|
||||
INT 33
|
||||
INT 32
|
||||
|
||||
PRMERR: MOV DX,INVPRM ;Invalid parameter
|
||||
JP ERROR
|
||||
BADDSK:
|
||||
MOV AX,CS
|
||||
MOV DS,AX
|
||||
MOV AH,SETDRV
|
||||
MOV DL,[CURDRV]
|
||||
INT 33
|
||||
MOV DX,DIRBAD
|
||||
JP ERROR
|
||||
DRVMOV: MOV DL,AL ;Correct drive designator
|
||||
DRVSET:
|
||||
MOV B,[WRKDRV],DL ;Save drive indicator
|
||||
INC DL ;FOR FCB SET
|
||||
MOV B,[ALLDRV],DL ;FCB ok now
|
||||
DEC DL
|
||||
CALL DRVXCG ;Change drives and do map read
|
||||
CMP B,[BX],0FEH ;Check for initialized disk
|
||||
JNE BADDSK
|
||||
PUSH DS
|
||||
PUSH ES
|
||||
POP DS
|
||||
MOV [DSKSIZ],DX ;Number of allocation units
|
||||
MOV [SECSIZ],CX ;Size of physical sector
|
||||
MOV AH,0
|
||||
MOV [CLUSSIZ],AX ;Sectors per cluster
|
||||
MOV CX,DX
|
||||
MOV DI,MAP
|
||||
XOR AX,AX
|
||||
REP
|
||||
STOW ;Zero out allocation map
|
||||
MOV CX,AX
|
||||
MOV [ALLOC],AX ;Count of allocation units used
|
||||
MOV [FILECNT],AX ;Number of files found
|
||||
MOV [DELCNT],AX ;Number of files deleted due to error
|
||||
MOV BP,DI
|
||||
MOV [NAMTAB],BP ;First address of file list
|
||||
MOV DX,DI
|
||||
MOV AH,SETDMA
|
||||
INT 21H
|
||||
MOV AH,SRCHFST
|
||||
MOV DX,ALLFILE
|
||||
INT 21H
|
||||
INC AL
|
||||
POP ES ;ES:BX point to FAT
|
||||
JNZ GETFILES
|
||||
JMP COMPMAP
|
||||
GETFILES:
|
||||
INC CX ;Count number of files
|
||||
ADD DI,44 ;Separate in file in list by 44 bytes
|
||||
MOV DX,DI
|
||||
MOV AH,SETDMA
|
||||
INT 21H
|
||||
MOV AH,SRCHNXT
|
||||
MOV DX,ALLFILE
|
||||
INT 21H
|
||||
INC AL
|
||||
JNZ GETFILES ;Loop until all files are in list
|
||||
MOV [FILECNT],CX
|
||||
MOV CX,1 ;File number (position in list)
|
||||
MOV DX,[DSKSIZ]
|
||||
INC DX ;Maximum cluster number
|
||||
MOV [MAXCLUS],DX
|
||||
ADD BP,34 ;Point to "first cluster" entry
|
||||
EACHFIL:
|
||||
XOR AX,AX ;No. of clusters in file
|
||||
MOV SI,[BP] ;First cluster of file
|
||||
CMP SI,[MAXCLUS] ;Make sure it's legal
|
||||
MOV DI,BADDIR
|
||||
JA BADFIRST
|
||||
OR SI,SI ;Check for zero-length file
|
||||
JZ HAVENDJ
|
||||
SCANFAT:
|
||||
MOV DI,CX
|
||||
SHL SI
|
||||
XCHG DI,[SI+MAP-4] ;Xchange current map entry with file no.
|
||||
SHR SI
|
||||
OR DI,DI ;Should be zero for unallocated cluster
|
||||
JNZ CROSSLINK
|
||||
INC AX ;Count cluster as part of this file
|
||||
CALL UNPACK
|
||||
JZ FORCEND ;Make sure cluster knows it's allocated
|
||||
CMP DI,0FF8H ;Bigger than this means End of File
|
||||
HAVENDJ:JAE HAVEND
|
||||
CMP DI,[MAXCLUS] ;Make sure it's a legal value
|
||||
JA FORCEND
|
||||
MOV SI,DI
|
||||
JP SCANFAT ;Visit each cluster allocated to file
|
||||
|
||||
BADFIRST:
|
||||
PUSH AX ;Because FILERR will pop it later
|
||||
MOV [BP+2],AX ;AX is zero
|
||||
MOV [BP+4],AX ;Set size to zero so we won't change it
|
||||
MOV AX,CX
|
||||
MOV DX,44
|
||||
DEC AX
|
||||
MUL AX,DX ;Get position in file name table
|
||||
MOV DX,AX
|
||||
ADD DX,[NAMTAB]
|
||||
MOV AH,DELETE
|
||||
INT 21H
|
||||
PUSH DS
|
||||
PUSH CX
|
||||
PUSH AX
|
||||
CALL DRVXCG ;Reset dirty bit to rewrite FAT
|
||||
POP AX
|
||||
POP CX
|
||||
POP DS
|
||||
OR AL,AL ;SEE IF WE HAVE A VALID DIRECTORY
|
||||
JZ DISKOK
|
||||
JMP BADDSK
|
||||
DISKOK:
|
||||
INC [DELCNT] ;Count one deleted file
|
||||
MOV DX,BADDIR
|
||||
JP FILERR
|
||||
|
||||
CROSSLINK:
|
||||
MOV DX,LINKED
|
||||
PUSH AX
|
||||
MOV AH,PRINTBUF
|
||||
INT 21H
|
||||
MOV AX,DI
|
||||
CALL PRINTNAM
|
||||
MOV DX,FILE2
|
||||
MOV AH,PRINTBUF
|
||||
INT 33
|
||||
MOV AX,CX
|
||||
CALL PRINTNAM
|
||||
MOV DX,CRLF
|
||||
MOV AH,PRINTBUF
|
||||
INT 33
|
||||
POP AX
|
||||
ADD [ALLOC],AX
|
||||
JMP SIZSET1
|
||||
|
||||
FORCEND:
|
||||
; Come here if a cluster allocated to a file contained an illegal
|
||||
; link--either a zero (meaning unallocated), or a value larger than
|
||||
; the maximum cluster number, but not End of File. Put an End of File
|
||||
; mark there so the FAT will at least be well-formed.
|
||||
MOV DX,0FFFH
|
||||
CALL PACK
|
||||
MOV DX,BADCLUS
|
||||
PUSH AX
|
||||
|
||||
FILERR:
|
||||
MOV AH,PRINTBUF
|
||||
INT 21H
|
||||
MOV AX,CX
|
||||
CALL PRINTNAM
|
||||
MOV DX,CRLF
|
||||
MOV AH,PRINTBUF
|
||||
INT 21H
|
||||
POP AX
|
||||
|
||||
HAVEND:
|
||||
ADD [ALLOC],AX ;Total up allocated clusters
|
||||
MOV SI,AX
|
||||
MOV AX,[BP+2]
|
||||
MOV DX,[BP+4] ;AX:DX now have file length
|
||||
PUSH CX
|
||||
MOV CX,[CLUSSIZ]
|
||||
DEC CX
|
||||
ADD AX,CX
|
||||
ADC DX,0
|
||||
INC CX
|
||||
SCALE:
|
||||
SHR CX
|
||||
JC SCALED
|
||||
SHR DX
|
||||
RCR AX
|
||||
JP SCALE
|
||||
SCALED:
|
||||
DIV AX,[SECSIZ]
|
||||
OR DX,DX
|
||||
JZ HAVSIZ
|
||||
INC AX
|
||||
HAVSIZ:
|
||||
CMP AX,SI ;See if file size corresponds with allocation
|
||||
JZ SIZSET
|
||||
XOR DI,DI
|
||||
MOV CX,[CLUSSIZ]
|
||||
CALL UNSCALE
|
||||
MOV [BP+6],SI
|
||||
MOV [BP+8],DI
|
||||
MOV DX,BP
|
||||
SUB DX,34
|
||||
MOV AH,OPEN
|
||||
INT 21H
|
||||
OR AL,AL
|
||||
JZ DISKOK2
|
||||
JMP BADDSK
|
||||
DISKOK2:
|
||||
MOV AX,[SECSIZ]
|
||||
MOV [BP-27+14],AX ;Make record size=sector size
|
||||
MOV CX,0
|
||||
MOV AH,BLKWRT
|
||||
INT 21H
|
||||
MOV AH,CLOSE ;Write back corrected directory entry
|
||||
INT 21H
|
||||
PUSH DS
|
||||
CALL DRVXCG ;Change the drives and get the map
|
||||
POP DS
|
||||
MOV DX,BADSIZ
|
||||
MOV AH,PRINTBUF
|
||||
INT 21H
|
||||
POP AX
|
||||
PUSH AX
|
||||
CALL PRINTNAM
|
||||
MOV DX,CRLF
|
||||
MOV AH,PRINTBUF
|
||||
INT 21H
|
||||
SIZSET:
|
||||
POP CX
|
||||
SIZSET1:
|
||||
ADD BP,44 ;Scan next file
|
||||
INC CX
|
||||
CMP CX,[FILECNT]
|
||||
JA COMPMAP
|
||||
JMP EACHFIL
|
||||
; Now compare the allocation map we have made with the FAT. Any
|
||||
; clusters not allocated in the map will be released.
|
||||
COMPMAP:
|
||||
XOR AX,AX ;Keep count of clusters released
|
||||
MOV BP,MAP
|
||||
MOV SI,2 ;First usable cluster number
|
||||
MOV CX,[DSKSIZ]
|
||||
RELCLUS:
|
||||
TEST [BP],-1 ;Allocated in our map?
|
||||
JNZ NXTCLUS ;If so, skip to next
|
||||
CALL UNPACK
|
||||
JZ NXTCLUS ;If not allocated, skip to next
|
||||
XOR DX,DX
|
||||
CALL PACK ;Change to "Free" status
|
||||
INC AX ;Count clusters released
|
||||
NXTCLUS:
|
||||
INC BP
|
||||
INC BP
|
||||
INC SI
|
||||
LOOP RELCLUS
|
||||
OR AX,AX ;Any clusters released?
|
||||
JZ REPORT ;If not, do final report
|
||||
MOV BX,FREED
|
||||
CALL DISPCLUS
|
||||
REPORT:
|
||||
; Make status report. Include no. of files, total disk space,
|
||||
; free space on disk, total memory, and free memory.
|
||||
SEG CS
|
||||
MOV DL,[CURDRV]
|
||||
MOV AH,SETDRV
|
||||
INT 21H
|
||||
MOV SI,[FILECNT]
|
||||
SUB SI,[DELCNT]
|
||||
XOR DI,DI
|
||||
MOV BX,NUMFIL
|
||||
CALL DISP32BITS
|
||||
MOV AX,[DSKSIZ]
|
||||
MOV BX,DSKSPC
|
||||
CALL DISPCLUS
|
||||
MOV AX,[DSKSIZ]
|
||||
SUB AX,[ALLOC]
|
||||
MOV BX,FRESPC
|
||||
CALL DISPCLUS
|
||||
MOV AX,[2]
|
||||
MOV DX,16
|
||||
MUL AX,DX
|
||||
MOV SI,AX
|
||||
MOV DI,DX
|
||||
MOV BX,TOTMEM
|
||||
CALL DISP32BITS
|
||||
MOV AX,[2]
|
||||
MOV DX,CS
|
||||
SUB AX,DX
|
||||
MOV DX,16
|
||||
MUL AX,DX
|
||||
MOV SI,AX
|
||||
MOV DI,DX
|
||||
MOV BX,FREMEM
|
||||
CALL DISP32BITS
|
||||
CALL WRTFRC ;Force all writes and handle write
|
||||
;protect violation
|
||||
SEG CS
|
||||
MOV B,DL,[CURDRV] ;Get default
|
||||
MOV AH,SETDRV ;And make it current again
|
||||
INT 21H
|
||||
INT 20H ;All done
|
||||
|
||||
WRTFRC: ;********************************************************
|
||||
; This code forces all writes by performing a disk
|
||||
; reset (function 13). When the attempt to write
|
||||
; the allocation table fails in the case of a write-
|
||||
; protected diskette, this logic determines if the
|
||||
; allocation table had changed and if no changes were
|
||||
; made a normal termination will be forced
|
||||
;*********************************************************
|
||||
MOV AX,DS
|
||||
PUSH DS ;Must first intercept INT 24H
|
||||
MOV ES,AX
|
||||
XOR AX,AX
|
||||
MOV DS,AX
|
||||
MOV SI,90H
|
||||
MOV DI,INT24 ;will move vector to local address
|
||||
MOV CX,2
|
||||
CLD ;So move will increment
|
||||
REP
|
||||
MOVW ;Vector now locally stored
|
||||
MOV AL,24H ;
|
||||
MOV AH,37
|
||||
MOV DX,WRTPRT ;
|
||||
POP DS ;Get local segment
|
||||
INT 21H ;Interrupt vector now set
|
||||
MOV AH,13
|
||||
INT 21H
|
||||
PUSH ES ;Will now reset INT 24H vector
|
||||
XOR AX,AX
|
||||
MOV ES,AX
|
||||
CLD
|
||||
MOV DI,90H
|
||||
MOV SI,INT24
|
||||
MOV CX,2
|
||||
REP
|
||||
MOVW
|
||||
POP ES
|
||||
RET
|
||||
|
||||
WRTPRT: ;*********************************************************
|
||||
; This logic is designed to handle the case where
|
||||
; CHKDSK found no problems and upon rewriting the
|
||||
; allocation table (by the DOS) the disk was write-
|
||||
; protected and an error thus occured. With no problems
|
||||
; this code will cause normal termination, otherwise
|
||||
; normal error handling will occur.
|
||||
;*********************************************************
|
||||
EI ;Run with interrupts live
|
||||
AND DI,0FFH ;See if write-protect
|
||||
JNZ WRT100 ;Do normal error handling
|
||||
CMP AH,3 ;File allocation write?
|
||||
JNZ WRT100 ;If not do normal handling
|
||||
SEG CS
|
||||
CMP [WRKDRV],AL ;Correct drive?
|
||||
JNZ WRT100 ;
|
||||
SEG CS
|
||||
CMP B,[CHGCLS],1 ;Legitimate change?
|
||||
JZ WRT100 ;If so do normal handling
|
||||
XOR AL,AL ;Ignore the error
|
||||
IRET
|
||||
WRT100: SEG CS
|
||||
MOV SI,AX ;Save AX
|
||||
PUSH DX
|
||||
MOV DL,[CURDRV] ;Fetch current drive
|
||||
MOV AH,SETDRV
|
||||
INT 33 ;Drive now ok
|
||||
POP DX ;Restore DX
|
||||
MOV AX,SI ;Restore AX
|
||||
SEG CS
|
||||
JMP L,[INT24] ;Do normal recovery
|
||||
|
||||
|
||||
DRVXCG:
|
||||
;**********************************************
|
||||
; WILL CHANGE DEFAULT TO WRKDRV READ THE FAT
|
||||
; AND CHANGE THE DEFAULT BACK TO CURDRV
|
||||
;**********************************************
|
||||
SEG CS
|
||||
MOV DL,[WRKDRV] ;Will change the default to this
|
||||
MOV AH,SETDRV
|
||||
INT 33 ;Default now "WRKDRV"
|
||||
MOV AH,GETMAP
|
||||
INT 33
|
||||
PUSH DX
|
||||
PUSH AX
|
||||
SEG CS
|
||||
MOV DL,[CURDRV] ;Get current drive
|
||||
MOV AH,SETDRV
|
||||
INT 33
|
||||
POP AX
|
||||
POP DX
|
||||
RET
|
||||
|
||||
|
||||
UNPACK:
|
||||
MOV DI,SI
|
||||
SHR DI
|
||||
ADD DI,SI
|
||||
SEG ES
|
||||
MOV DI,[DI+BX]
|
||||
TEST SI,1
|
||||
JZ HAVCLUS
|
||||
SHR DI
|
||||
SHR DI
|
||||
SHR DI
|
||||
SHR DI
|
||||
HAVCLUS:
|
||||
AND DI,0FFFH
|
||||
RET
|
||||
|
||||
PACK:
|
||||
;*************************************************************
|
||||
; ES:BX POINTER TO THE BASE OF THE ALLOCATION TABLE
|
||||
; SI CLUSTER NUMBER TO BE PACKED
|
||||
; DX POINTER TO BE PLACED IN CLUSTER (SI)
|
||||
;*************************************************************
|
||||
MOV B,[CHGCLS],1 ;INDICATE CLUSTER CHANGED
|
||||
PUSH SI
|
||||
MOV DI,SI
|
||||
SHR SI
|
||||
ADD SI,BX
|
||||
ADD SI,DI
|
||||
SHR DI
|
||||
SEG ES
|
||||
MOV DI,[SI]
|
||||
JNC ALIGNED
|
||||
SHL DX
|
||||
SHL DX
|
||||
SHL DX
|
||||
SHL DX
|
||||
AND DI,0FH
|
||||
JP PACKIN
|
||||
ALIGNED:
|
||||
AND DI,0F000H
|
||||
PACKIN:
|
||||
OR DI,DX
|
||||
SEG ES
|
||||
MOV [SI],DI
|
||||
POP SI
|
||||
RET
|
||||
|
||||
UNSCALE:
|
||||
SHR CX
|
||||
JC RET
|
||||
SHL SI
|
||||
RCL DI
|
||||
JP UNSCALE
|
||||
|
||||
DISPCLUS:
|
||||
MUL AX,[SECSIZ]
|
||||
MOV CX,[CLUSSIZ]
|
||||
MOV SI,AX
|
||||
MOV DI,DX
|
||||
CALL UNSCALE
|
||||
DISP32BITS:
|
||||
PUSH BX
|
||||
XOR AX,AX
|
||||
MOV BX,AX
|
||||
MOV BP,AX
|
||||
MOV CX,32
|
||||
CONVLP:
|
||||
SHL SI
|
||||
RCL DI
|
||||
XCHG AX,BP
|
||||
CALL CONVWRD
|
||||
XCHG AX,BP
|
||||
XCHG AX,BX
|
||||
CALL CONVWRD
|
||||
XCHG AX,BX
|
||||
ADC AL,0
|
||||
LOOP CONVLP
|
||||
; Conversion complete. Print 10-digit number with 2 leading blanks.
|
||||
MOV CX,1B10H
|
||||
CALL OUTWORD
|
||||
MOV AX,BX
|
||||
CALL OUTWORD
|
||||
MOV AX,BP
|
||||
CALL OUTWORD
|
||||
POP DX
|
||||
MOV AH,PRINTBUF
|
||||
INT 21H
|
||||
RET
|
||||
|
||||
OUTWORD:
|
||||
PUSH AX
|
||||
MOV DL,AH
|
||||
CALL OUTBYTE
|
||||
POP DX
|
||||
OUTBYTE:
|
||||
MOV DH,DL
|
||||
SHR DL
|
||||
SHR DL
|
||||
SHR DL
|
||||
SHR DL
|
||||
CALL DIGIT
|
||||
MOV DL,DH
|
||||
DIGIT:
|
||||
AND DL,0FH
|
||||
JZ BLANKZER
|
||||
MOV CL,0
|
||||
BLANKZER:
|
||||
DEC CH
|
||||
AND CL,CH
|
||||
OR DL,30H
|
||||
SUB DL,CL
|
||||
MOV AH,OUTCH
|
||||
INT 21H
|
||||
RET
|
||||
|
||||
CONVWRD:
|
||||
ADC AL,AL
|
||||
DAA
|
||||
XCHG AL,AH
|
||||
ADC AL,AL
|
||||
DAA
|
||||
XCHG AL,AH
|
||||
RET
|
||||
|
||||
PRINTNAM:
|
||||
PUSH CX
|
||||
DEC AX
|
||||
MOV CX,44
|
||||
MUL AX,CX
|
||||
MOV SI,AX
|
||||
ADD SI,[NAMTAB]
|
||||
ADD SI,8
|
||||
MOV CX,8
|
||||
MOV AH,OUTCH
|
||||
CALL PRINTCNT
|
||||
MOV DL," "
|
||||
INT 21H
|
||||
MOV CL,3
|
||||
CALL PRINTCNT
|
||||
POP CX
|
||||
RET
|
||||
|
||||
PRINTCNT:
|
||||
LODB
|
||||
MOV DL,AL
|
||||
INT 21H
|
||||
LOOP PRINTCNT
|
||||
RET
|
||||
|
||||
ALLFILE:DB -1,0,0,0,0,0,6 ;Extended FCB
|
||||
ALLDRV: DB 0,"???????????"
|
||||
DS 25
|
||||
|
||||
FILE2: DB " and $"
|
||||
BADDRV: DB "Invalid drive specification$"
|
||||
INVPRM: DB "Invalid parameter$"
|
||||
BADCLUS:DB "Allocation error for file $"
|
||||
BADDIR: DB "Directory error-file : $"
|
||||
LINKED: DB "Files cross-linked: "
|
||||
DB 13,10
|
||||
DB " $"
|
||||
BADSIZ: DB "File size error for file $"
|
||||
DIRBAD: DB "Diskette not initialized $"
|
||||
FREED: DB " bytes disk space freed",13,10,13,10,"$"
|
||||
NUMFIL: DB " disk files",13,10,"$"
|
||||
DSKSPC: DB " bytes total disk space",13,10,"$"
|
||||
FRESPC: DB " bytes remain available",13,10,13,10,"$"
|
||||
TOTMEM: DB " bytes total memory",13,10,"$"
|
||||
FREMEM: DB " bytes free"
|
||||
CRLF: DB 13,10,"$"
|
||||
|
||||
DSKSIZ: DS 2
|
||||
SECSIZ: DS 2
|
||||
CLUSSIZ:DS 2
|
||||
CHGCLS: DB 0 ;IF RESET TO 1-ALLOCATION TABLE UPDATED
|
||||
WRKDRV: DB 0
|
||||
INT24: DS 4
|
||||
FILECNT:DS 2
|
||||
NAMTAB: DS 2
|
||||
ALLOC: DS 2
|
||||
MAXCLUS:DS 2
|
||||
DELCNT: DS 2
|
||||
CURDRV: DS 1
|
||||
DS 100H
|
||||
STACK:
|
||||
|
||||
MAP:
|
||||
|
||||
Reference in New Issue
Block a user