;********************************************************************** ;* Module : STRINGS.MOD ;* Programmer: Tony Papadimitriou ;* Purpose : String and character manipulation related OS-called routines ;* Language : MC68HC11 (ASM11 v1.83+) ;* Status : FREEWARE, Copyright (c) 1999 by Tony Papadimitriou ;* Segments : RAM : Variables ;* : ROM : Code ;* : SEG9 : OS definitions (this allows adding more functions) ;* History : 99.10.31 v1.00 Original (copied from 99.10.26 OS11.MOD) ;* : 99.11.07 v1.01 Added fDeleteWord, fFillMem ;********************************************************************** #ifmain #LISTOFF #INCLUDE 811E2.INC #INCLUDE COMMON.INC #INCLUDE OSERRORS.INC #LISTON #SEG9 ORG $FF00 #endif #SEG9 #ifndef OSCommands OSCommands equ * #endif fPos equ *-OSCommands/2 ;Get character position dw ?Pos fFillMem equ *-OSCommands/2 ;Fill memory with character dw ?FillMem fCompareBuf equ *-OSCommands/2 ;Compare buffers at X and Y dw ?Compare fCompareStr equ *-OSCommands/2 ;Compare ASCIZ strings at X and Y dw ?CompareStr fUpString equ *-OSCommands/2 ;Convert ASCIZ string to uppercase dw ?UpString fUpPascalStr equ *-OSCommands/2 ;Convert Pascal-type string pointed to by X to uppercase dw ?UpPascalStr fLength equ *-OSCommands/2 ;Get ASCIZ string length dw ?Length fInsert equ *-OSCommands/2 ;Insert char within ASCIZ string dw ?Insert fDelete equ *-OSCommands/2 ;Delete char within ASCIZ string dw ?Delete fDeleteWord equ *-OSCommands/2 ;Delete chars until target char dw ?DeleteWord fNoLeadChar equ *-OSCommands/2 ;Convert leading RegB chars to RegA char dw ?NoLeadChar fGarble equ *-OSCommands/2 ;Garble buffer at X with seed in RegA dw ?Garble #PAGE ;Operating System routines expanded ********************************************************************** * Operating System routines expanded * ********************************************************************** #ROM ; Purpose: Get the position of a character starting from X ; Input : X points to beginning position in search buffer (0,CR,LF terminated) ; : A holds character to search for ; : B holds number of matches to perform ; Output : IF FOUND: B holds offset from X to found character (ready for ABX) ; : Carry is Clear ; : IF NOT FOUND: B is unaffected and Carry is Set ; Note(s): Target character can also be one of the terminators ?Pos ldx X_,y ;and load X ldb B_,y beq ?Pos.NotFound.Out ;zero matches=not found pshb ;save number of matches clrb ;Initialize position counter ?Pos.Loop lda ,x ;get the buffer character incb ;count this character inx ;point to next buffer character cmpa A_,y ;is it the same as the target? beq ?Pos.Found ;if so, go count the match tsta ;was it the end of the string beq ?Pos.NotFound ;if so, we didn't find target ; next four lines can be commented if you wish to work with ASCIZ strings only cmpa #CR beq ?Pos.NotFound ;A CR means end of string cmpa #LF beq ?Pos.NotFound ;A LF means end of string ; previous four lines can be commented if you wish to work with ASCIZ strings only bra ?Pos.Loop ;and try again ?Pos.NotFound pulb ;rather than error code, return original B value ?Pos.NotFound.Out sec ;indicates "not found" rts ?Pos.Found dec B_,y ;one less match to look for bne ?Pos.Loop ;repeat until target match count decb ;make counter zero-based (for ABX) stb B_,y ;save result for user ins ;de-allocate saved B (faster than PULB) clc ;indicates "found" rts ; Routine: FillMem ; Purpose: Fill memory buffer with given value ; Input : X -> buffer ; : A holds character ; : B holds length ; Output : None ?FillMem ldb B_,y ;get length beq ?FillMem.Exit ;on zero length, exit lda A_,y ;get character to fill with ldx X_,y ;get buffer pointer ?FillMem.Loop sta ,x ;save char in buffer inx ;point to next buffer char decb ;one less to fill bne ?FillMem.Loop ;repeat for all ?FillMem.Exit clc ;never an error from here rts ; Purpose: Compare buffers pointed by X and Y (case sensitive) ; Input : B holds maximum number of bytes to compare ; : X points to start of first memory ; : Y points to start of second memory ; Output : N Z V C set or cleared in accordance with the CMP instruction ; : Allows BEQ, BNE, BLO, BHS, etc. to be used on result just as if ; : a regular CMPA instruction had been used. ; Note(s): All registers except N Z V C flags are preserved ; : Violates Carry-Set on error rule. Carry set is used for result (BLO, etc.) ?Compare pshy ldb B_,y ;load parameters beq ?Compare.OK ;zero length always OK ldx X_,y ldy Y_,y ?Compare.Loop lda ,x ;get character at X cmpa ,y ;is the same as the one at Y? bne ?Compare.No ;No, get out then decb ;are we done with all characters? beq ?Compare.OK ;Yes, and they all compare OK inx ;No, let's go check next ones iny bra ?Compare.Loop ?Compare.OK clc ;Z flag always set when here, so CMP OK assumed ?Compare.No pulx ;use X instead of Y for speed and size tpa ;save CCR in A (actual CMP result) psha anda #$0F ;mask off unused flags ldb CCR_,x ;get original CCR andb #$F0 ;mask off result bits stb CCR_,x ;save it ora CCR_,x ;combine with CMP results sta CCR_,x ;and save final CCR ldb B_,x ;get original B just in case carry is set pula tap ;restore local CCR rts ; Purpose: Compare ASCIZ strings pointed by X and Y (case sensitive) ; Input : X points to first ASCIZ string ; : Y points to second ASCIZ string ; Output : N Z V C set or cleared in accordance with the CMP instruction ; : Allows BEQ, BNE, BLO, BHS, etc. to be used on result just as if ; : a regular CMPA instruction had been used. ; Note(s): All registers except N Z V C flags are preserved ; : Violates Carry-Set on error rule. Carry set is used for result (BLO, etc.) ?CompareStr pshy ldx X_,y ldy Y_,y ?CompareStr.Loop lda ,x ;get character at X cmpa ,y ;is the same as the one at Y? bne ?Compare.No ;No, get out then tsta ;are we done with all characters? beq ?Compare.OK ;Yes, and they all compare OK inx ;No, let's go check next ones iny bra ?CompareStr.Loop ; Purpose: Convert ASCIZ string pointed to by X to uppercase ; Input : X_,y->string ; Output : X_,y->STRING ?UpString ldx X_,y ;point X to string ?UpString.Loop lda ,x beq ?UpString.Exit jsr Upcase ;convert to uppercase sta ,x cpx #RAM_END ;do not run wild outside of RAM bhs ?UpString.Exit inx bne ?UpString.Loop ;avoids infinite loops ldb #errOutOfRange sec rts ?UpString.Exit clc rts ; Purpose: Convert Pascal-type string pointed to by X to uppercase ; Input : X_,y->string ; Output : X_,y->STRING ?UpPascalStr ldx X_,y ;point X to string ldb ,x ;get length in B beq ?UpPascalStr.Exit ;get out now, if length is 0 ?UpPascalStr.Loop inx ;point to data byte lda ,x jsr Upcase ;convert to uppercase sta ,x decb bne ?UpPascalStr.Loop ?UpPascalStr.Exit clc rts ; Routine: Length ; Purpose: Get the length of an ASCIZ string ; Input : X points to string ; Output : B holds length if Carry Clear, error "errOutOfRange" if Carry Set ; Note(s): Maximum string length is 255 characters ?Length clrb ldx X_,y ?Length.Loop tst ,x beq ?Length.Exit incb beq ?Length.Error ;more than 255 is an error inx bne ?Length.Loop ;avoids infinite loops ?Length.Error ldb #errOutOfRange sec rts ?Length.Exit stb B_,y clc rts ; Routine: Insert ; Purpose: Insert a character within an ASCIZ string ; Input : X points to string ; : A holds character ; : B holds position before which to insert ; Output : None ?Insert lda A_,y ldb B_,y beq ?Insert.Exit ;Nothing to do, get out ldx X_,y decb ;Make zero-based abx lda ,x ;get first character beq ?Insert.End ;are we done moving string up? ?Insert.Loop ldb 1,x ;get next character sta 1,x inx ;go upstring tba ;move next char to A bne ?Insert.Loop ;repeat until A is zero ?Insert.End sta 1,x ;save trailing zero ldx X_,y ;now, add the character lda A_,y ldb B_,y decb abx sta ,x ?Insert.Exit clc rts ; Routine: Delete ; Purpose: Delete a character within an ASCIZ string ; Input : X points to ASCIZ string ; : B holds position to delete (first=1) ; Output : None ?Delete ldb B_,y ?Delete.Local beq ?Delete.Exit ;Nothing to do, get out ldx X_,y decb ;Make zero-based abx ?Delete.Loop tst ,x ;check if at end-of-string beq ?Delete.Exit ;are we done? lda 1,x ;get next character sta ,x ;move down one place inx ;go upstring bne ?Delete.Loop ;repeat (avoids infinite loops) ?Delete.Exit clc rts ; Routine: DeleteWord ; Purpose: Delete chars until (and including) a certain char ; Input : X points to ASCIZ string ; : A holds target character (zero if for remaining string) ; Output : None ?DeleteWord lda A_,y ;get target character ldx X_,y ;point X to buffer ldb #1 cmpa ,x ;is first character the target? beq ?DeleteWord.Exit ;yes, go delete it and exit bsr ?Delete.Local ;Delete first character bra ?DeleteWord ;repeat (need to reload regs) ?DeleteWord.Exit tsta ;to reset the zero flag bsr ?Delete.Local ;Delete target character clc rts ; Routine: NoLeadChar ; Purpose: Convert leading RegB chars to RegA char ; Input : A Character to use for filling ; : B Character to be replaced ; : X->Buffer area to change leading zeros to char in RegA ; Output : X->Buffer with leading RegB characters changed to RegA character ; Note(s): Terminates at first non-matching (RegB) character ?NoLeadChar ldx X_,y lda A_,y ldb B_,y ?NoLeadChar.Loop cmpb ,x bne ?NoLeadChar.Exit sta ,x ;replace with RegA character inx bne ?NoLeadChar.Loop ;avoids infinite loops ?NoLeadChar.Exit clc rts ; Routine: Garble ; Purpose: Garble buffer at X with seed in RegA ; Input : X->buffer ; : A=8-bit seed to use for garbling ; : B=Length of buffer ; Output : Buffer at X is garbled with seed in RegA ?Garble ldx X_,y ldb B_,y beq ?Garble.Exit ;no more bytes to process ?Garble.Loop lda ,x ;get character eora A_,y ;XOR with user seed sta ,x ;put character back in buffer inx ;point to next character decb ;are we done with all chars? bne ?Garble.Loop ?Garble.Exit clc rts #ifmain #include DISPATCH.MOD #endif #ROM