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206 lines
7.1 KiB
Plaintext
206 lines
7.1 KiB
Plaintext
; C02 filesys.h02 assembly language subroutines
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; for all Commodore 8 bit machines
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; Requires external functions ADDDST, FOPENA, FREAD, FSKIP,
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; FSBCMD, FSCBFR, FSCDRA, FSGBFR, FSOPTS, and SETSRC
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; external zero page locations BFRHI, BFRLO, DSTHI, DSTLO,
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; SRCHI, and SRCLO
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; and external locations FSCNTR, FSDVNO, FSLFNO, and TEMP0
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;String Constants
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FSDIRP DC "$0:",0 ;Disk Directory Prefix
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;opndir() - Open Directory for Reading
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;Args: A = Drive/Options
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; Y,X = Pointer to Directory Name
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;Uses: BFRHI,BFRLO = Pointer to Work Buffer
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;Sets: SRCHI,SRCLO = Pointer to Directory Name
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;Returns: A = File Pointer
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; 0 - Error
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OPNDIR: JSR SETSRC ;Save Directory Pointer
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STY FSCNTR ;Set File Count to 0
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JSR FSOPTS ;Parse Options Byte
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JSR FSCDRV ;If Device is Not Disk Drive
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BEQ CLSDIX ; Return Error
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LDA #36 ;Set Command to "$"
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JSR FSBCMD ;and Build Command String
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SEC ;Set Flag to Concatenate
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JSR FSCBFR ;Concatenate Directory Name to Buffer
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JSR FSGBFR ;Get String Buffer Address
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JMP FOPENA ;Execute File Open (Alternate Entry Point)
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;clsdir() - Close Directory File
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;Args: A = Directory File Pointer
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;Returns: A = Error Code
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; 0 - Success
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CLSDIR: ORA #0 ;Check File Pointer
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BEQ CLSDIX ;If Not Zero
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JMP FCLOSE ;Close File Channel
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CLSDIX: RTS
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;rdhdr() - Read Directory Header
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;Note: Call once before first rddir()
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;Args: A = Directory File Pointer
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; Y,X = Pointer to HDRENT buffer
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;Sets: DSTHI,DSTLO = Pointer to HDRENT buffer
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;Returns: A = Disk Type
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; Y = Error Code (0=None)
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RDHDR: JSR SETDST ;Set Destination Address
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LDY #2 ;Set Record Length
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JSR FREAD ;and Read Record
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BCS RDHDRZ ;If Error, Exit
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STY TEMP0 ;Set Skipped Bytes to 0
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LDA (DSTLO),Y ;Get Disk Version
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PHA ;and Save It
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CMP #$43 ;If 8050/8250
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LDY #2 ;Skip Unused bytes
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BNE RDHDRC
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CMP #$41 ;If 4040/1541/1571
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BNE RDHDRD ; Skip BAM
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LDA FSLFNO ; Get Channel
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LDY #140 ; Set Record Length
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RDHDRC: STY TEMP0 ; Save Number of Skipped Bytes
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JSR FSKIP ; and Skip Bytes
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BCS RDHDRX ; If Error, Exit
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RDHDRD: LDA #2 ;Add 2 Bytes
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JSR ADDDST ;to Destination Address
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LDA FSLFNO ;Get Channel
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LDY #24 ;Set Record Length
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JSR FREAD ;and Read Record
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BCS RDHDRX ;If Error, Exit
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LDA #228 ;Set Padding Bytes
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SEC
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SBC TEMP0 ;Subtract Bytes Skipped
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TAY ;Set as Record Length
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LDA FSLFNO ;Get Channel
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JSR FSKIP ;and Skip Bytes
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LDY #23 ;Set Index to 24
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RDHDRN: LDA (DSTLO),Y ;Load Byte
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CMP #$A0 ;If Shifted Space
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BNE RDHDRS
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LDA #0 ;Change to 0
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STA (DSTLO),Y
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RDHDRS: DEY ;Decrement Index
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BPL RDHDRN ;and Loop if Not Negative
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INY ;Set Error Code to 0
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RDHDRX: PLA ;Retrieve Disk Type
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RDHDRZ: RTS
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;rddir() - Read Directory Entry
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;Args: A = Directory File Pointer
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; Y,X = Pointer to DIRENT buffer
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;Uses: BFRHI,BFRLO = Pointer to Work Buffer
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;Sets: DSTHI,DSTLO = Pointer to DIRENT buffer
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;Returns: A = File Type (0=Null Entry)
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; Y = Error Code (0=None)
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RDDIR: JSR SETDST ;Set Destination Address
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TAX ;Save LFN
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LDY #32 ;Set Record Length
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INC FSCNTR ;Increment File Count
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LDA FSCNTR ;Load It
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AND #$07 ;Modulo 8
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BNE RDDIRB ;If 0
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LDY #30 ; Change Record Length
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RDDIRB: TXA ;Restore LFN
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JSR FREAD ;and Read Record
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RDDIRC: LDA #0 ;Initialize Return Value
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BCS RDDIRX ;If Error, Exit
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LDA (DSTLO),Y ;Get File Type
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PHA ;and Save it
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LDA #3 ;Add 3 Bytes
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JSR ADDDST ;to Destination Address
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LDY #15 ;Set Index to 15
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RDDIRN: LDA (DSTLO),Y ;Load Byte
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CMP #$A0 ;If Shifted Space
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BNE RDDIRS
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LDA #0 ;Change to 0
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STA (DSTLO),Y
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RDDIRS: DEY ;Decrement Index
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BPL RDDIRN ;and Loop if Not Negative
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INY ;Set Error Code to 0
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PLA ;Restore File Type
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RDDIRX: RTS
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;setdrv() - Set Current Drive
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;Args: A = Drive Identifier
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;Returns: A = Drive Identifier
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; 0 - None/Error
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SETDRV: JSR FSCDRA ;Check Device Number
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BCS SETDRX ;If Disk Drive
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STA FSDVNO ; Write to Device#
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SETDRX: RTS
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;getdrv() - Get Current Drive
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;Returns: A = Drive Identifier
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; 0 - None/Error
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GETDRV: LDA FSDVNO ;Load Current Device#
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JMP FSCDRA ;Check if Disk Drive
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;setdir() - Set Current Directory
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;Args: A = Drive Identifier
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; Y,X = Pointer to Directory Name
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;Uses: BFRHI,BFRLO = Pointer to Work Buffer
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;Sets: SRCHI,SRCLO = Pointer to Directory Name
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;Returns: A = Error Code
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; $00 - Successful
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; $FF - Inapplicable
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SETDIR: JSR SETSRC ;Save Pointer
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JSR FSOPTS ;Parse Drive Argument
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JSR FSGBFR ;Get String Buffer Address
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;command is "/0:Directory"
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;assuming 0 is disk number
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;of course this is switched from normal command syntax
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RTS
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;getdir() - Get Current Directory
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;Args: A = Drive Identifier
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; Y,X = Pointer to String
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;Uses: BFRHI,BFRLO = Pointer to Work Buffer
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;Sets: DSTHI,DSTLO = Pointer to String
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;Returns: A - Length of Directory Name
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; $00 - Root
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; $FF - Inapplicable
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GETDIR: ;Return Inapplicable (fall through)
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;mkdir() - Create Directory
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;Args: A = Drive Identifier
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; Y,X = Pointer to Directory Name
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;Uses: BFRHI,BFRLO = Pointer to Work Buffer
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;Sets: SRCHI,SRCLO = Pointer to Directory Name
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;Returns: A = Error Code
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; $00 - Successful
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; $FF - Inapplicable
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MKDIR: ;Return Inapplicable (fall through)
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;rmdir() - Remove Directory
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;Args: A = Drive Identifier
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; Y,X = Pointer to Directory Name
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;Uses: BFRHI,BFRLO = Pointer to Work Buffer
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;Sets: SRCHI,SRCLO = Pointer to Directory Name
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;Returns: A = Error Code
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; $00 - Successful
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; $FF - Inapplicable
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RMDIR: ;Return Inapplicable (fall through)
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;remove() - Delete File
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;Args: A = Drive Identifier
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; Y,X = Pointer to File Name
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;Uses: BFRHI,BFRLO = Pointer to Work Buffer
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;Sets: SRCHI,SRCLO = Pointer to File Name
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;Returns: A = Error Code
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; $00 - Successful
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; $FF - Inapplicable
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REMOVE: ;Return Inapplicable (fall through)
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;rename() - Rename File
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;Args: A = Drive Identifier
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; Y,X = Pointer to Destination File Name
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;Uses: SRCHI,SRCLO = Pointer to Source File Name
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; BFRHI,BFRLO = Pointer to Work Buffer
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;Sets: DSTHI,DSTLO = Pointer to Destination File Name
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;Returns: A = Error Code
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; $00 - Successful
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; $FF - Inapplicable
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RENAME: LDA #$FF ;Return Inapplicable
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RTS
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