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Assembly Source File | 1990-12-19 | 23.8 KB | 664 lines

;«RM82»«TS8,16,24,32,40,48» ;updated 11/21/90 ;============================================================================ ; Copyright (C) Copr. 1990 by Sidney J. Kelly ; All Rights Reserved. ; Sidney J. Kelly ; 150 Woodhaven Drive ; Pittsburgh, PA 15228 ; home phone 412-561-0950 (7pm to 9:30pm EST) ;============================================================================ DOSSEG .MODEL MEDIUM Public GETDRIVE, GETSUB, DRVSPACE, SETDRIVE, SUBEXIST, FLOPPYREADY, FLOPPYDRIVES, HARDRIVES, GETCURRENTNAME, TRUENAME, GETFULLPATH .CODE ; Please do not remove Copyright DB 13,10,'Copyright Copr. (C) 1990 Sidney J. Kelly',13,10 Copyright1 DB 'All Rights Reserved',13,10,26 ;============================================================================ ; DECLARE SUB GETDRIVE(DRIVE$) ; CALL GETDRIVE(DRIVE$) ; Returns current drive name ; If LEN(DRIVE$)=0 then nothing happens ; ; Assumes that DRIVE$ is a near string, not TYPEd or part of a far string ; array. In other words, assumes DRIVE$ is in DGROUP ;============================================================================ EVEN GETDRIVE PROC FAR Push BP Mov BP,SP ;save base frame Mov BX,[BP+6] Mov CX,[BX] Jcxz Error1 ;test LEN(Drive$) if 0 exit Mov AH,19h Int 21h Add AL,'A' ;Add A to value Xor AH,AH ;clear AH to 0 Mov BX,[BP+6] ;get address of string descripter Mov BX,[BX+2] ;get actual string address Mov [BX],AL ;store AL in Drive$ Error1: Pop BP Ret 2 ; one parameter passed ; so remove it GETDRIVE ENDP ;============================================================================ ; DECLARE SUB GETSUB (PATH AS STRING * 64, PATHLEN%) ; Returns current subdirectory path, without Drive:\, (i.e. no "A:\") ; if LEN(Path$) not = to 64 then returns a pathlen% of -1 ; ; PATH$ can not be a TYPEd string or a variable in a string array ; because there is a chance that string will be outside DGROUP. ; This routine assumes that Path$ is a near string. ;============================================================================ EVEN GETSUB PROC FAR Push BP ;set up base pointer Mov BP,SP ;allow us to address the stack Push SI ;save index registers Push DI ; ditto Mov AX,SS Mov ES,AX ;set ES = to DGROUP for scasb assume ES:@data Mov BX,[BP+8] ;get address of Path$ Mov AX,ES:[BX] Cmp AX,64 ;if LEN(PATH$) <> 64 JNE Error ;then Error Mov SI,ES:[BX+2] ;it has to be 64 so Pathlen% value is Mov DI,SI ;calculated correctly below Xor DL,DL ;select default drive Mov AH,47h ;get current directory Int 21h JC Error ;if carry set, directory invalid Mov CX,64 ;determine length of Path$ Xor AL,AL ;clear AL, the value to search ;for ending null Cld ;clear direction flag Repnz Scasb ;scan until reach end of Path$ Mov AX,63 ;determine length of Path$ Sub AX,CX Jmp Short finis Error: Mov AX,-1 ;return Pathlen% = -1 if error finis: Mov BX,[BP+6] Mov ES:[BX],AX Pop DI ;restore registers used Pop SI Pop BP Ret 4 GETSUB ENDP ;============================================================================ ; DECLARE SUB DRVSPACE (DRIVE$,SPACE&) ; checks if DRIVE$ <"A" or >"z", or if >"Z" & less <"a" ; Drive of "@" gives the current drive ; Invalid DRIVE$ gives a free space of 0 ; Note: DOS does not correctly adjust this if use JOIN or SUBST and ; try to determine the size of a non-default drive. ;============================================================================ EVEN DRVSPACE PROC FAR Push BP Mov BP,SP Mov BX,[BP+8] ;get drive letter from first parameter Mov CX,[BX] Jcxz Error_Set ;DRIVE$ is a null string so exit Mov BX,[BX+2] ;get string address Mov DL,[BX] ;store string in DL Xor DH,DH Cmp DL,'@' ;check if less than "@" JB Error_Set Cmp DL,'z' ;check if > "z" JA Error_Set Cmp DL,'@' ;select current if "@" JNE Spec_drive ;check if want current drive Mov AH,36h Xor DX,DX ;0 is current drive number Int 21h ;read current drive free space Cmp AX,0ffffh ;did an error occur? JE Error_Set ;routine returned invalid drive Jmp Short Quit ;valid drive Spec_drive: And DL,1fh ;allow A to Z or a to z Dec DL Cmp DX,19h ;final range check if > "Z" and < "a" JA Error_Set ;greater than "Z" so quit Inc DL Mov AH,36h Int 21h Cmp AX,0ffffh ;did an error occur? JE Error_Set Quit: ;store free SPACE& in DX:AX pair Mul CX ;multiply sectors/cluster * bytes per sector Mul BX ;multiply product by no. free clusters Jmp Short Finis1 ;the order of math is important Error_Set: Xor AX,AX ;returns a free SPACE& of 0 Mov DX,AX ;saves a clock on 8086 chips Finis1: Mov BX,[BP+6] ;Stores the SPACE& in 2d parameter Mov [BX],AX ;store lowbyte from AX Mov [BX+2],DX ;store hibyte from DX Pop BP Ret 4 DRVSPACE ENDP ;============================================================================ ; DECLARE SUB SETDRIVE (DRIVE$,ErrCode%) ; no change occurs if DRIVE$ <"A" or >"z", or if >"Z" & less <"a" ; Returns ErrCode% = 0 (False) if no errors ; = -1 (True) if errors ; error checking includes range check and real test if a change occured ;============================================================================ EVEN SETDRIVE PROC FAR Push BP Mov BP,SP ;set base frame pointer Mov AH,19h ;get default drive Int 21h Xor CH,CH Mov CL,AL ;store in CL Mov BX,[BP+8] ;get drive letter from first parameter Mov BX,[BX+2] ;get string address Mov DL,[BX] ;store string in DL Xor DH,DH Cmp DL,'A' ;check if less than "A" JB Error_Set1 Cmp DL,'z' ;check if > "z" JA Error_Set1 And DL,1fh ;allow A to Z or a to z Dec DL ;subtract one to make DX zero based drive number Cmp DL,19h ;final range check if > "Z" and < "a" JA Error_Set1 ;greater than "Z" so quit Cmp CL,DL je Quiter ;current equal's new drive so don't bother Mov AH,0Eh ;change drive Int 21h Mov AX,1900h ;get current directory again to ;see if change worked Int 21h Cmp AL,DL ;DL holds user selected drive JNE Error_Set1 ;unable to make a change so set error Quiter: Xor AX,AX ;clears ERRORCODE% to 0 Jmp Short Finis2 Error_Set1: Mov AX,-1 ;Sets ERRORCODE% to -1 if error occured Finis2: Mov BX,[BP+6] ;Stores the ERRORCODE% in 2d parameter Mov [BX],AX Pop BP Ret 4 SETDRIVE ENDP ;============================================================================ ; DECLARE SUB SUBEXIST (PATH$+CHR$(0),ErrCode%) ; Returns ErrCode% = 0 (False) if no errors, ; = -1 (True) if errors ; If a drive change is required, subdirectory on other drive will be made ; the "current" subdirectory on that other drive. ; ; PATH$ cannot be a TYPEd string or a variable in a string array ; because there is a chance that string will be outside DGROUP. String ; cocentenation is used to make sure it is in DGROUP. ;============================================================================ EVEN StoragePath db 0,':\', 64 dup (0) ;temporarily store information. ;By storing DATA in code seg, ;this routine cannot be used ;under OS/2. We do it ;to save space in DGROUP EVEN SUBEXIST PROC FAR Push BP Mov BP,SP Push DS Push SI Push DI Mov AH,19h ;get original drive Int 21h Mov StoragePath,AL ;store drive number for later use Push DS ;save DS Mov AX,CS ;faster than PUSH CS, POP DS on 8088 Mov DS,AX ;set DS == CS Mov AH,47h ;get original subdirectory Xor DL,DL ;of current drive ASSUME DS:@code ;tell DOS of change Mov SI, offset StoragePath+3 ;give original path Mov DI, SI Int 21h Pop DS ASSUME DS:@data Mov BX,[BP+8] ;get Path$ Mov DI,[BX+2] ;store address of Path$ in DI Mov CX,[BX] ;get length of string in CX Jcxz String_Too_Short;if Path$ too short, bail out Cmp CX,03 ;check string size JB Short_Path ;if LEN(Path$) < 3, ;don't check for drive Cmp byte PTR [DI+1],':' ;check for colon JNE Short_Path ;skip drive check if no colon Mov DL,[DI] ;drive letter to DL And DX,001fh ;capitalize letter Dec DX ;reduce by zero, for zero bias Mov AH,0Eh ;select drive Int 21h Inc DI ;move pointer past DRIVE Inc DI ;move pointer past colon Short_Path: Mov DX,DI ;move pointer to DX Mov AH,3Bh ;change to new "current" directory Mov SI,-1 ;assume error Int 21h JC SubEx_Err ;error if carry set Xor SI,SI ;no error so return 0 SubEx_Err: Mov BX,[BP+6] Mov [BX],SI ;store result from SI in ErrCode% Mov DL, StoragePath ;using original default drive Mov AH,0Eh ;select original drive Int 21h Add DL,65 ;convert drive letter to ASCII character Mov StoragePath,DL ;give us original drive letter Mov AX,CS ;set DS == CS Mov DS,AX Mov AH,3Bh ;change back to original subdirectory ASSUME DS:@code, ES:NOTHING Mov DX, offset StoragePath Int 21h SubEx_Finis: Pop DI ; restore saved registers Pop SI Pop DS ASSUME DS:@data Pop BP Ret 4 ; remove 2 * 2 parameters String_Too_Short: Mov SI,-1 ;Path$ a "" string, why bother Mov BX,[BP+6] ;report ErrCode of TRUE Mov [BX],SI ;store result from SI in ErrCode% Jmp Short SubEx_Finis SUBEXIST ENDP ;============================================================================ ; DECLARE SUB FLOPPYREADY (DRIVE$, ErrCode%) ; Tests if floppy drive is ready, on a one floppy system ; treats drive B: as equivalent to drive A: ; ErrCode ; 128 = Time Out Error ; 80 = Track error ; -1 = Drive$ is not valid ; 0 = All a.o.k. ; Note : A critical error routine is not necessary for this routine to work ;============================================================================ EVEN FLOPPYREADY PROC FAR Push BP Mov BP,SP Push SI call _Floppy ;get actual # of floppies in AX Mov SI,0003 ;assume 3 drives Mov BX,[BP+8] Mov CX,[BX] ;test LEN(DRIVE$) Jcxz ErrorFound ;if zero, then quit Mov BX,[BX+2] ; get actual string Mov DL,[BX] ;store in DL And DL,1Fh ;capitalize it Cmp DL,2 JNE @f ;Check if want drive B: on Cmp AL,1 ;a one floppy system JNE @f Dec DL ;make call for B:, mimic A: @@: Cmp DL,AL ;if greater than allowed floppy # JA ErrorFound Dec DL ;zero bias Redo: Mov AX,401h Mov CX,1 Xor DH,DH ;verify 1 sector of disk Int 13h Or AH,AH ;check for errors Mov AX,0000 ;can't use XOR because ;wd change flags JZ NormalExit ;found none so exit Dec SI ;decriment no. of drives JZ @f ;jump if no more drives Xor AH,AH ;reset drive if error Int 13h ;try again Jmp Short Redo @@: Mov AX,0100h ;read reset status Int 13h Xchg AH,AL ;put return value in AL Xor AH,AH ;clear AH NormalExit: Mov BX,[BP+6] Mov [BX],AX ;store in ErrCode Pop SI ;restore saved registers Pop BP Ret 4 ;remove 2 * 2 parameters ErrorFound: Mov AX,-1 ;return -1 for error Jmp NormalExit FLOPPYREADY ENDP ;--------------------------------------------------------------------- ; DECLARE SUB FLOPPYDRIVES(NoDrives%) ; Returns number of physical floppy drives in system ;--------------------------------------------------------------------- EVEN FLOPPYDRIVES PROC FAR Push BP Mov BP,SP Call _Floppy Mov BX,[BP+6] Mov [BX],AX ;store AX in value Pop BP Ret 2 FLOPPYDRIVES ENDP EVEN _Floppy Proc Near Int 11h Shr AX,1 ;test if have any floppies JB @f ;jump if carry flag set Xor AX,AX ;else clear AX Jmp Short Fins1 ;quit @@: And AX,60h ;mask off floppy bits Mov CL,05 ;count the number of floppies Shr AX,CL Inc AX ;increment the final count Fins1: Ret _Floppy ENDP ;--------------------------------------------------------------------- ; DECLARE SUB HARDDRIVES(NoDrives%) ; Returns number of physical hard disks in system ;--------------------------------------------------------------------- EVEN HARDRIVES PROC FAR Push BP Mov BP,SP Xor AX,AX Mov ES,AX Mov BX,ES:[0475h] ; get info from 0040:0075h Mov AX,BX And AX,3 ; keep within range 0-4 Mov BX,[BP+6] Mov [BX],AX ; store AX in value Pop BP Ret 2 HARDRIVES ENDP ;========================================================================= ; DECLARE SUB GETCURRENTNAME (FName as STRING * 64, FileLength%) ; Returns current filename for dos version 3.xx and above ; if LEN(FName$) <> 64 then returns a FileLength% of -1 ; ; FName$ can not be a TYPEd string or a variable in a string array ; because there is a chance that string will be outside DGROUP. ; This routine assumes that FName$ is a near string. ; Function returns an error if DOS version < 3.xx since function is not ; supported for that version. ;========================================================================= EVEN Env_Seg dw 0 Env_Len dw 0 EVEN GETCURRENTNAME PROC FAR Push BP ; set up base pointer Mov BP,SP ; allow us to address the stack Push SI ; save index registers Push DI ; ditto Push DS ; save segment registers Mov AH,30h ; check if DOS version > 2.xx Int 21h Cmp AL,3 JB Error12 ; error if less than 3.00 Cld ; clear direction flag Mov AH,62h ; get PSP address Int 21h Mov ES,BX ; store PSP address in ES Mov ES,ES:[002ch]; store PSP environment segment ; address in ES Mov Env_Seg,ES ; save environment address Xor DI,DI ; clear DI Xor AL,AL ; clear AL Mov CX,8000h ; assume environment segment ; is 32kb max DoubleNullLoop: Repne Scasb ; search using ES:DI ; until find a null ; (can't use scasw because the ; double null may fall on odd ; address) Scasb ; find the second null Jne DoubleNullLoop Add DI,2 ; skip over markers ; db 0, 1 Mov Env_Len,DI ; save end of environment ; address Mov AX,SS Mov ES,AX ; set ES = to DGROUP for scasb Assume ES:@data Mov BX,[BP+8] ; get address of Path$ Mov AX,ES:[BX] Cmp AX,64 ; if LEN(PATH$) <> 64 Jne Error12 ; then Error Mov SI,ES:[BX+2] ; it has to be 64 so FileLength% ; value is calculated correctly below Mov DI,SI ; copy SI:offset in DI for use by ; Movsb and Scasb below. Push DI Mov CX,64 ; copy Name into FName$ Mov DS,Env_Seg Mov SI,Env_Len Rep Movsb ; copy DS:SI to ES:DI Mov CX,64 ; length of FName$ Xor AL,AL ; clear AL, the search value Pop DI ; search for null at end of name Repnz Scasb ; uses ES:DI to search ; scan until reach end of FName$ Mov AX,63 ; determine length of FName$ Sub AX,CX ; before the null Jmp Short Finis12 Error12: Mov AX,-1 ; return FileLength% = -1 ; if error Finis12: Mov BX,[BP+6] Mov ES:[BX],AX Pop DS ; restore registers used Pop DI Pop SI Pop BP Ret 4 ; remove 2 * 2 parameters GETCURRENTNAME ENDP ;============================================================================ ; DECLARE SUB TRUENAME (OrigFile$+CHR$(0), TrueFName$, FileLength%) ; Purpose: ; Allows user to test for SUBST, ASSIGN, and JOIN using an ; undocumented call for DOS Version 3.xx and above ; The returned name will contain technically correct Drive: and Path ; information. However, the OrigFile$ is not checked so ? and * may be ; used, the OrigFile$ may even be non-existant. ; ; Shortcuts: ; OrigFile$ = "." to obtain current drive & subdirectory name ; OrigFile$ = ".." to obtain immediate parent drive & subdirectory name ; ; Usage: ; TrueFName$ = STR$(67,0) ; CALL TRUENAME(OrigFile$ + CHR$(0), TrueFName$, FileLength%) ; IF FileLength% = -1 THEN ; Error ; ELSE ; TrueFName$=LEFT$(TrueFName$, FileLength%) ; END IF ;============================================================================ EVEN TRUENAME PROC FAR Push BP Mov BP,SP ; make stack addressable Push DI ; save variables we use Push SI Mov AH,30h ; check if DOS version > 2.xx Int 21h Cmp AL,3 ; AL contains the major version JB Error15 ; If less than 3.00, Error15 Mov BX,[BP+8] ; get TrueFName$ Mov CX,[BX] ; get length of string JCXZ Error14 ; if zero, Error Cmp CX,67 ; if not equal to 67 bytes, Error JNE Error14 Mov DI,[BX+2] ; get address of TrueFName$ string Mov BX,[BP+10] ; get length of OrigFile$ Mov CX,[BX] ; if length is zero, then Error JCXZ Error14 Mov SI,[BX+2] ; get address of OrigFile$ Mov AX,DS ; faster than PUSH & POP on 8088 Mov ES,AX ; make ES==DS Push DI ; save address of DI ; input string DS:SI, output ES:DI Mov AH,60h ; call undocumented Expand Path Name Int 21h ; Dettmann, DOS Programmer's Reference ; 2d Edition (Que 1989), page 660 ; Very good book Pop DI ; reset DI JC Error14 ; bad character in OrigFile$ Mov CX,67 ; length of TrueFName$ Xor AL,AL ; clear AL, the search value Cld ; clear the direction flag Repnz Scasb ; uses ES:DI to search ; scan until reach end of TrueFName$ Mov AX,66 ; determine length of TrueFName$ Sub AX,CX ; before the null Jmp Short Quit14 ; end routine Error14: Mov AX,-1 ; return a -1 for FileLength% Quit14: Mov BX,[BP+6] Mov [BX],AX ; store AX in FileLength% Pop SI ; restore saved registers Pop DI Pop BP Ret 6 ; clear variables off stack Error15: ; report DOS version is <3.xx Xor AX,AX ; so no danger of SUBST, JOIN Jmp Short Quit14 ; or ASSIGN TRUENAME ENDP ;========================================================================= ; DECLARE SUB GETFULLPATH (PATH$, PATHLEN%) ; Returns current subdirectory path, with Drive:\, e.g. "A:\" ; if LEN(Path$) <> 67 then returns a pathlen% of -1 ; ; PATH$ can not be a TYPEd string or a variable in a string array ; because there is a chance that string will be outside DGROUP. ; This routine assumes that Path$ is a near string. ;========================================================================= EVEN GETFULLPATH PROC FAR Push BP ;set up base pointer Mov BP,SP ;allow us to address the stack Push SI ;save index registers Push DI ; ditto Mov BX,[BP+8] ;get address of Path$ Mov AX,[BX] Cmp AX,67 ;if LEN(PATH$) <> 67 JNE Error2 ;then Error Mov AX,SS Mov ES,AX ;set ES == to DGROUP for scasb assume ES:@data Mov AH,19h ;get current drive Int 21h Add AL,'A' ;Add A to value Xor AH,AH ;clear AH to 0 Mov BX,[BX+2] ;get actual string address Mov Byte Ptr [BX],AL ;store AL in Drive$ Mov Byte Ptr [BX+1],':' ;add colon Mov Byte Ptr [BX+2],'\' ;add backlash ADD BX,3 ;increase address by 3 to skip "A:\" Mov SI,BX ;it has to be 67 so Pathlen% value is Mov DI,SI ;calculated correctly below Xor DL,DL ;clear DL to get Mov AH,47h ;get current directory Int 21h JC Error ;if carry set, directory invalid Mov CX,64 ;find ending null in Path$ Xor AL,AL ;clear AL, the value to search for Cld ;clear direction flag Repnz Scasb ;uses ES:DI to search Path$ Mov AX,63 ;determine length of Path$ Sub AX,CX Add AX,3 ;add length of drive "A:\" Jmp Short finis2 Error2: Mov AX,-1 ;return Pathlen% = -1 if error finis2: Mov BX,[BP+6] Mov [BX],AX Pop DI ;restore registers used Pop SI Pop BP Ret 4 GETFULLPATH ENDP END