992 lines
64 KiB
Plaintext
992 lines
64 KiB
Plaintext
*::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*
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* *
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* DELETE Funtion Handler *
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* *
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*----------------------------------------------------------------*
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* *
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* The DELETE function handler (FNDELETE, $AD2B) uses the *
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* COMNOPEN routine ($AB28) to locate the desired file. COMNOPEN *
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* configures the FM work area, reads in a fresh VTOC and then *
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* searches the directory sectors for the file description entry *
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* of the wanted file. (The links to the first directory sector *
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* are housed in the VTOC. Each subsequent directory sector *
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* contains the links to the next directory sector. The link *
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* bytes of the last directory sector are zeroed out.) *
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* Each directory contains up to seven different file *
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* descriptions. An example of the data contained in a file *
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* description is shown below: *
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* FIL1TSTK DS 1 ;Track # of first T/S list for file 1. *
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* FIL1TSSC DS 1 ;Sector # of first T/S list for file 1. *
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* FIL1TYPE DS 1 ;File type code for file 1. ($00=Text, *
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* ;$01=Integer, $02=Applesoft, $04=Binary, *
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* ;$08=S-type, $10=Relocatable, $20=A-type *
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* ;and $40=B-type.) The hi bit is set on *
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* ;locked files. For example, $02=unlocked *
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* ;Applesoft and $82=locked Applesoft. *
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* FIL1NAME DS 30 ;Name of file 1. If a file name less than *
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* ;30 bytes is used, trailing spaces are *
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* ;added to the name to fill the buffer. *
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* FIL1SIZE DS 2 ;Size of file 1 in terms of the number of *
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* ;sectors used. *
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* (If a file was deleted, the track # of the first T/S list sec *
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* was copied to the last byte position of the name field. The *
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* original track # byte (FIL1TSTK) was then overwritten with *
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* an #$FF.) *
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* As each directory sector is read in, an attempt is made *
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* to locate a file description which contains the name of the *
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* file wanted. If, after searching all directories, the name of *
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* the wanted file is not found, a second search is made to *
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* locate the first available space in a directory where a new *
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* file description can be placed (in case the command can *
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* legally create a new file). If no free space is located, a *
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* disk-full error message is printed. *
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* If a free space is found, NEWDESCRP ($B21C) copies the *
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* name of the wanted file from the primary file name buffer *
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* (PRIMFNBF, $AA75) into the new entry space. A check is then *
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* made to see if the command can legally create a new file. The *
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* identifying command byte (NDX2CMD, $AA5F) is used to index a *
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* table of command attributes (CMDATTRB, $A909). Because bit0 *
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* of the first attribute byte associated with the delete *
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* command is clear, a new file cannot legally be created. As a *
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* result, the delete command is exited with a file-not-found *
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* error message. *
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* If a (non-deleted) description entry containing the name *
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* of the wanted file is located, execution branches to the *
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* FILLINWA routine ($ABA6). FILLINWA uses the information *
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* contained in the description entry to customize the FM work *
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* area. The first T/S list belonging to the wanted file is then *
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* read in (READTS, $A5FE). Next, the file type code is checked. *
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* The delete command is aborted with a file-locked message if *
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* the file is locked. *
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* If the file is not locked, the track value of the file's *
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* first T/S list is copied to the last character position of the *
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* name field in the description. The original track number byte *
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* is then replaced with an #$FF to mark the file as deleted. *
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* WRDIRECT ($B037) is used to write the updated directory sector *
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* to the disk. After re-reading the file's first T/S list into *
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* the T/S list buffer, execution returns to the delete function *
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* handler at $AD5C. *
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* The DELFREE routine ($AD5E) is used to free up all the *
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* data sectors that are listed in the T/S list. Sectors are *
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* released by setting the appropriate bit in the TRKMAP bytes of *
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* the VTOC. (See the linear disassembly of the VTOC and the *
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* SUB2FREE routine ($B2DD) listed below for further explanation.)*
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* After all data sectors listed in the T/S list are *
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* freed, the sector belonging to the T/S list is also released *
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* ($ADD7). Execution then branches back to the RDTS4DEL routine *
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* ($AD54) to read in the next T/S list and repeat the freeing up *
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* process (if necessary). Once all the sectors associated with *
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* the file are released, a forced branch is made to the DONEDEL *
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* routine ($AD83). DONEDEL writes the updated VTOC and then *
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* returns to delete command handler. *
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* *
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*::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*
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(AD2B)
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FNDELETE JSR COMNOPEN ;Locate a file with the same name & open it.
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*** NOTE ***
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* Not all of the common open routine is
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* listed below because not all of it
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* applies to the DELETE function.
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* Common open routine.
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(AB28)
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COMNOPEN JSR ZWRKAREA ;Initialize the work area.
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* Zero out the FM work area so it can be customized
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* in accordance with the calling function.
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* (Although some work bytes may not be subsequently
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* alterd, don't be lulled into thinking that they
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* are not important. Zero values are just as relevant
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* as non-zero values.)
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* (P.S. Don't confuse the FM work area with its image
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* (FM work buffer) that is housed in the chain of
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* DOS buffers.)
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(ABDC)
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ZWRKAREA LDA #0
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TAX ;Initialize the x-index.
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ZEROWRKA STA FMWKAREA,X ;Put a $00 byte in work area.
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INX
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CPX #45 ;Work area is 45 bytes long.
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(ABE5) BNE ZEROWRKA
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* Begin customizing the work area.
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* Get volume, drive, slot & catalog track
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* values from the FM parameter list. Put
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* drive, slot*16, catalog track and
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* complemented volume number in the work area.
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(ABE7) LDA VOLFM ;Volume number.
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EOR #$FF ;Calculate 1's complement of volume #.
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STA VOLWA
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LDA DRVFM ;Drive #.
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STA DRVWA
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LDA SLOTFM ;Get slot #.
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ASL ;Calculate slot * 16.
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ASL
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ASL
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ASL
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TAX ;Set (x) = slot * 16.
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STX SLOT16WA
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LDA #$11 ;Normal catalog trk = #17.
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STA TRKWA
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(AC05) RTS
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(AB2B) LDA #1 ;Describe sector length as 256 bytes
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(AB2D) STA SECSIZWA+1 ;(in the FM work area).
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* Get record length from the FM parameter
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* list & put it in the FM work area.
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* (Don't allow a zero length. If zero,
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* change it to one.)
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(AB30) LDX RECLENFM+1
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LDA RECLENFM
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BNE STRECLEN ;Non-zero record length is ok.
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CPX #0
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BNE STRECLEN
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INX ;Was zero, make it one instead.
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STRECLEN STA RECLENWA ;Put length in FM work area.
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STX RECLENWA+1
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(AB43) JSR GETFNTRY ;Try to find a directory sector for the file.
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* Locate or create a file entry in the
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* directory buffer.
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* Make two searches if necessary:
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* - Search1 - try to locate entry with same name as file wanted.
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* - Search2 - couldn't locate entry corresponding to file
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* wanted so create a new entry in first available
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* space in the directory sector.
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(B1C9)
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GETFNTRY JSR READVTOC ;Read in the VTOC so we can get the link to
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;TRKMAPS & to the first directory sector.
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* Read the Volume Table of Contents (VTOC).
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(AFF7)
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READVTOC LDA #1 ;Read opcode for RWTS.
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(AFF9) BNE RDWRVTOC ;ALWAYS.
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* Code common to read/write VTOC.
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(AFFD)
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RDWRVTOC LDY ADRVTOC ;Get address of VTOC from the
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STY IBBUFP ;FM constants table & designate it
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LDY ADRVTOC+1 ;as the I/O buffer in RWTS's IOB.
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STY IBBUFP+1
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LDX TRKWA ;Enter RWTS driver with (x)/(y) equal
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LDY #0 ;to the trk/sec values of the VTOC.
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(B00E) JMP RWTSDRVR ;Call driver to read/write the VTOC.
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------------
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* Read/Write Track/Sector driver.
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(B052)
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RWTSDRVR .
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.
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(See dism'bly of RWTS driver using READ.)
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.
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.
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(RTS)
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* Point A4L/H at the primary file name buffer.
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(B1CC) LDA FNAMBUFM ;Get address of the name buffer from the
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STA A4L ;FM parameter list & put it in the A4L/H
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LDA FNAMBUFM+1 ;pointer.
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(B1D4) STA A4L+1
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* Try to find the directory sector with the
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* wanted file name & read it into the directory
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* sector buffer. Make two searches if necessary.
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* On the first search, try to find a matching name.
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* If that doesn't work, do a second search to store
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* the description in the first available file
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* description field in a directory sector.
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(B1D6) LDA #1 ;Initialize the search counter (SCRNSRCH)
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SETSRCH STA SCRNSRCH ;in the FM scratch space for two searches.
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(B1D8) ;(1 = search1, 0 = search2)
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(B1DB) LDA #0 ;Initialize offset of file description from
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STA SECNXDIR ;the very first directory sector.
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CLC ;(c)=0=signal to read first directory sec.
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GETDIRSC INC SECNXDIR ;Kick up offset from first directory.
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(B1E4) JSR RDDIRECT ;Go read directory sector into buffer.
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* Read a directory sector.
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(B011)
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RDDIRECT PHP ;Save (c) on stack:
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; (c) = 0 = read 1rst directory sector.
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; (c) = 1 = read next directory sector.
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(B012) JSR PT2DIRBF
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* Designate the directory sector buffer
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* as I/O buffer in RWTS's IOB.
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(B045)
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PT2DIRBF LDA ADRDIRBF ;Get addr of direc
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STA IBBUFP ;sec buf from the
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LDA ADRDIRBF+1 ;FM constants tbl
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STA IBBUFP+1 ;& designate it as
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(B051) RTS ;as the I/O buffer.
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(B015) PLP ;Check if 1rst directory sec or not.
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(B016) BCS RDNXTDIR ;Go read next directory sector.
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* Read the first directory sector.
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* (Carry = 0.)
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(B018)
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RDFIRDIR LDY FIRDIRSC ;(y)/(x) = trk/sec vals of first directory
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LDX FIRDIRTK ;sector (from the VTOC buffer).
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(B01E) BNE DODIRRD ;ALWAYS - go read in directory sector.
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* Read the next directory sector.
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* (Carry = 1.)
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(B020)
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RDNXTDIR LDX DIRLNKTK ;Get track of next directory sec from the
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;link in the current directory sector.
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(B023) BNE GETDIRLK ;Link not zeroed out.
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SEC ;Link zeroed out - exit with (c) = 1 to
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(B026) RTS ;signal there are no more directory secs.
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============
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(B027)
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GETDIRLK LDY DIRLNKSC ;Get sector of next directory sec from the
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;link in the current directory sector.
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* Call to read in the directory sector.
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(B02A)
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DODIRRD STX CURDIRTK ;Save trk/sec vals of directory sec that
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(B02D) STY CURDIRSC ;we are about to read so they will be
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;the current directory sec values for the
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;next time around.
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(B030) LDA #1 ;Read opcode for RWTS.
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(B032) JSR RWTSDRVR ;Call RWTS driver to do the read.
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* Read/Write Track/Sector driver.
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(B052)
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RWTSDRVR .
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.
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(See dis'mbly of RWTS driver using READ.)
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.
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.
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(RTS)
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(B035) CLC ;Link didn't zero out so signal that there
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(B036) RTS ;are more directory secs to read & exit.
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============
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(B1E7) BCS CHNGSRCH ;Link zeroed out, no more directory secs,
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;so go switch searches.
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(B1E9) LDX #0
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CKDIRTRK STX CURDIRNX ;Offset of file description into the current
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(B1EB) ;directory sector.
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(B1EE) LDA FIL1TSTK,X ;Get track number of first T/S list
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;for a particular file from the file
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;description entry in the directory sector.
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(B1F1) BEQ CHRSRCHA ;If trk=0, no more files in this direc sec.
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(B1F3) BMI CHRSRCHB ;Skip deleted file. (When a file is
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;deleted, #$FF is put in byte where trk #
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;of first T/S list is usually kept.
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* Compare the name found in the file
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* description entry portion of the
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* directory sector with the file name
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* wanted. (On entry, A4L/H points at
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* the primary file name buffer.)
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(B1F5) LDY #0 ;Initialize index to file name buffer.
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INX ;Point (x) at the first char position
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INX ;in the name field of description entry.
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CMPNAMES INX
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LDA (A4L),Y ;Get char of name from primary.
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CMP FIL1TSTRK,X ;Compare to char in name of description.
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BNE DONTMTCH ;Chars (and therefore names) don't match.
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INY
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CPY #30 ;Done all chars yet (0 to 29)?
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BNE CMPNAMES ;Chars matched, branch if more to check.
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LDX CURDIRNX ;All chars matched, so names matched.
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CLC ;Return with (x) = index to file
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(B20A) RTS ;description in current directory sector
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============ ;and with (c) = 0 to signal that the
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;correct file description was found.
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* Advance index to point at the next
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* potential file description entry.
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(B20B)
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DONTMTCH JSR NXPLUS35 ;Names didn't match, so adjust index
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;to point at the next entry.
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* Add 35 to the offset to point the index
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* at the next file description entry.
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* (Check to make sure that we don't index
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* right off the end of the directory sec.)
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(B230)
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NXPLUS35 CLC
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LDA CURDIRNX
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(B234) ADC #35 ;Add 35 to index. (Each file description
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;entry is 35 bytes long.)
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(B236) TAX ;Check if there is more space for entries
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CPX #245 ;in the current directory sector.
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(B239) RTS ;Exit with (c) conditioned:
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; (c) = 0 = more space in directory.
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; (c) = 1 = ran off end of directory.
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(B20E) BCC CKDIRTRK ;More potential file descriptions to check
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;in this directory sector.
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(B210) BCS GETDIRSC ;Go get next directory sector.
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------------
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* If we just completed the first search,
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* go back to do the second search.
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(B212)
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CHRSRCHA LDY SCRNSRCH ;(1 = search1, 0 = search2)
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(B215) BNE SETSRCH ;Go switch to second search.
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* If first search, skip deleted files.
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* If second search, fall through to store
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* the description in the first unused
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* space in the directory.
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(B217)
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CHRSRCHB LDY SCRNSRCH ;(1 = search1, 0 = search2)
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(B21A) BNE DONTMTCH
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* Couldn't locate the named file in the
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* directory description entries, so begin
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* creating a new description in the first available
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* space in a directory (in case command can
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* legally create a new file).
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(B21C)
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NWDESCRP LDY #0 ;Initialize index to primary file name buffer.
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INX ;Set index to first char position in the
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INX ;name field of the file description entry
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SETNWNAM INX ;space in the directory sector.
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LDA (A4L),Y ;Copy char from primary file name buffer
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STA FIL1TSTK,X ;to the directory description space.
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INY
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CPY #30 ;30 chars in name (0 to 29).
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BNE SETNWNAM ;Branch if more chars to copy.
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LDX CURDIRNX ;Return with (x) = index to file
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SEC ;description space in current directory
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(B22F) RTS ;sector & with (c)=1 to signal new entry
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============ ;was just created.
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* If first search, switch to second search.
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* If second search, link zeroed out because
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* there isn't enough room left on the
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* disk for a new entry. Therefore,
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* exit with a disk-full error message.
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(B23A)
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CHNGSRCH LDA #0 ;Used to reset search counter if
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;go back to start second search.
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(B23C) LDY SCRNSRCH ;(1 = search1, 0 = search2)
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(B23F) BNE SETSRCH ;Just did first search, so go start
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;the second search.
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(B241) JMP DISKFULL ;Even second search was unsuccesful
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------------ ;so go handle a disk-full error.
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(AB46) BCC FILLINWA ;Branch if found a directory sector with
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;name wanted in the file description entry.
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* Named file wasn't found in directory,
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* so prepare a new file entry in case
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* command can legally create a new file.
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(AB48) STX CURDIRNX ;Offset to new description entry in
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;case want to create a new file.
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* Check to see if command can
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* legally create a new file.
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(AB4B) LDX NDX2CMD ;(x) = index representing command.
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(AB4E) LDA CMDATTRB,X ;Get first byte containing description
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;of the given command's attributes.
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(AB51) LDX CURDIRNX ;(x) = index for new file description
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;entry into the directory sector.
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(AB54) LSR ;(c) = bit 0 of 1rst attribute byte.
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(AB55) BCS CREATNEW ;If (c) = 1, command can create a new file.
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;ALWAYS FALL THRU FOR DELETE FUNCTION (cause (c) = 0).
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* Command can't create a new file.
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* See which language we are using and
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* exit with the appropriate error msg.
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(AB57)
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NEWILLGL LDA CONDNFLG ;$00=warmstart, $01=reading, $40=A(RAM),
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;$80=coldstart & $C0=integer.
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(AB5A) CMP #$C0 ;Integer in ROM?
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BNE TOFILNOT ;No.
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(AB5E) JMP LNGNOTAV ;Yes - handle language-not-available error.
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-------------
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TOFILNOT JMP FILENOT ;Handle file-not-found error.
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(AB61) ------------
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* Fill in the FM work area buffer.
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* (Routine common to opening a new
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* or pre-existing file.)
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(ABA6)
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FILLINWA LDA FIL1TSTK,X ;T/S list trk val (from directory sec).
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STA FIRSTSTK
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LDA FIL1TSSC,X ;T/S list sec val (from directory sec).
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STA FIRTSSEC
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LDA FIL1TYPE,X ;File type (from directory sec).
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STA FILTYPFM
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STA FILTYPWA
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LDA FIL1SIZE,X ;File size (from directory sec).
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STA FILENSEC
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LDA FIL1SIZE+1,X
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STA FILENSEC+1
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STX BYTNXDIR ;Index into directory sec to description.
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LDA #$FF ;Pretend that the last data sector used had
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STX RELPREV ;a relative sector number (in relation to
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(ABCF) STA RELPREV+1 ;the entire file) of #$FFFF. NOTE: This
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;value is later used to trick the read and
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;write subfunctions into ignoring the data
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;sector currently in memory.
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(ABD2) LDA MXIN1TSL ;Dictate that a T/S list can only describe $7A
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(ABD5) STA MXSCURTS ;(#122) data sectors. Note: This value is later
|
|
;used by the read and write subfunctions to decide
|
|
;whether or not the T/S list currently in memory
|
|
;should be used.
|
|
|
|
* Read first T/S list sector
|
|
* to the T/S list buffer.
|
|
(ABD8) CLC ;(c) = 0 = signal 1rst T/S list sector.
|
|
(ABD9) JMP READTS ;Go read in the T/S list sector.
|
|
------------
|
|
|
|
* Read T/S list sector.
|
|
(AF5E)
|
|
READTS PHP ;Save (c) denoting if 1rst T/S list or not.
|
|
;(c) = 0 = read 1rst T/S list sec.
|
|
;(c) = 1 = read next T/S list sec.
|
|
(AF5F) JSR CKTSUPDT ;Write T/S list sec buf if updating is
|
|
;required. (If T/S list buf has changed
|
|
;since last read or write, then write it
|
|
;back to the disk so don't overwrite buf
|
|
;and lose information when read the new
|
|
;T/S list sector.)
|
|
|
|
* Check if T/S list requires updating.
|
|
* (ie. Has T/S list buf changed since
|
|
* the last read or write?)
|
|
(AF34)
|
|
CKTSUPDT LDA UPDATFLG
|
|
BMI WRITETS ;If bit 7 set, updating is required.
|
|
(AF39) RTS ;NOT APPLICABLE TO THE DELETE FUNCTION.
|
|
============
|
|
|
|
(AF62) JSR SETTSIOB ;Prepare RWTS's IOB for READING a T/S list.
|
|
|
|
* Prepare RWTS's IOB for reading
|
|
* or writing the T/S list sector.
|
|
(AF4B)
|
|
SETTSIOB LDA TSBUFFM ;Get adr of the T/S list buf from the FM
|
|
STA IBBUFP ;parameter list & designate T/S list buf
|
|
LDA TSBUFFM+1 ;as the I/O buffer in RWTS's IOB.
|
|
STA IBBUFP+1
|
|
LDX CURTSTRK ;Set (x)/(y) = trk/sec of current T/S list.
|
|
LDY CURTSSEC
|
|
(AF5D) RTS
|
|
|
|
(AF65) JSR SELTSBUF ;Select the T/S list buffer.
|
|
|
|
* Point A4L/H at the T/S list sector buffer.
|
|
(AF0C)
|
|
SELTSBUF LDX #2 ;Index for T/S list buf.
|
|
(AF0E) BNE PT2FMBUF ;ALWAYS.
|
|
|
|
(AF12)
|
|
PT2FMBUF LDA WRKBUFFM,X ;Get address of the desired buffer from
|
|
STA A4L ;the FM parameter list & put it in the
|
|
LDA WRKBUFFM+1,X ;A4L/H pointer.
|
|
STA A4L+1
|
|
(AF1C) RTS
|
|
|
|
(AF68) PLP ;Get saved (c) back from stack.
|
|
(AF69) BCS RDNXTTS ;If (c) = 1, already read first T/S list
|
|
;sec, so go read next one.
|
|
;(Not applicable at this point in time cause (c) = 0.)
|
|
|
|
* Read first T/S list sector.
|
|
* (Carry was clear.)
|
|
(AF6B)
|
|
RDFIRSTS LDX FIRSTSTK ;Set (x)/(y)=trk/sec of first T/S list sec.
|
|
LDY FIRTSSEC
|
|
(AF71) JMP RDTSLST ;Go read T/S list sector into buffer.
|
|
------------
|
|
|
|
* Subroutine to read/write T/S list sector.
|
|
(AFB5)
|
|
RDTSLST LDA #1 ;Read opcode for RWTS.
|
|
|
|
* Code common to read/write T/S list.
|
|
(AFB7)
|
|
RDWRTS STX CURTSTRK ;New T/S list sector trk/sec values (x)/(y)
|
|
STY CURTSSEC ;become current T/S list trk/sec values.
|
|
(AFBD) JSR RWTSDRVR ;Call RWTS driver to read/write current T/S list.
|
|
|
|
* Read or write the current T/S list.
|
|
(B052)
|
|
RWTSDRVR .
|
|
.
|
|
(See dis'mbly of RWTS driver using READ.)
|
|
.
|
|
.
|
|
(RTS)
|
|
|
|
* Update the FM work area
|
|
* (not in DOS buffer chain).
|
|
(AFC0) LDY #5 ;Offset into current T/S list buffer.
|
|
LDA (A4L),Y ;Get & save the relative sector number of
|
|
(AFC4) STA RELFIRST ;the first data sector described in this
|
|
;T/S list.
|
|
(AFC7) CLC ;Add maximum # of data secs that can be described
|
|
ADC MXSCURTS ;in this T/S list ($7A or #122).
|
|
STA RELASTP1 ;Store relative sector number (plus 1) of
|
|
INY ;the last data sector that can be described in list.
|
|
LDA (A4L),Y
|
|
STA REFIRST+1
|
|
ADC MXSCURTS+1
|
|
STA RELASTP1+1
|
|
CLC ;Return with "no error" signal.
|
|
(AFDB) RTS
|
|
============
|
|
|
|
(AD2E) LDX CURDIRNX ;(x) = index to file description entry in
|
|
;the directory sector buffer.
|
|
(AD31) LDA FIL1TYPE,X ;Get file type from the directory sec buf.
|
|
BPL ALTRNTRY ;Branch if file is not locked.
|
|
(AD36) JMP FILELOKD ;Err - can't DELETE a locked file so go
|
|
------------ ;handle error and exit.
|
|
|
|
* Get the track number of the file's first
|
|
* T/S list from the file description entry
|
|
* in the directory sec buf. Put it in the
|
|
* work area and write it over the last char
|
|
* position in the appropriate file name field
|
|
* in the directory sector.
|
|
(AD39)
|
|
ALTRNTRY LDX CURDIRNX ;(x) = index to the file description entry
|
|
;in the directory sector buffer.
|
|
(AD3C) LDA FIL1TSTK,X ;Get the trk # of the first T/S list sec.
|
|
STA FIRSTSTK ;Copy it into the work area and into the
|
|
(AD42) STA FIL1NAME+29,X ;last character position of the file
|
|
;name field description.
|
|
(AD45) LDA #$FF ;Replace the original track # of the T/S
|
|
STA FIL1TSTK,X ;list with #$FF to signal file is deleted.
|
|
LDY FIL1TSSC,X ;Put the sector # of the file's first T/S
|
|
STY FIRTSSEC ;list sec in the work area.
|
|
(AD50) JSR WRDIRECT ;Write the modified directory sector.
|
|
|
|
* Write the directory buffer.
|
|
(B037)
|
|
WRDIRECT JSR PT2DIRBF
|
|
|
|
* Designate the directory sector buffer
|
|
* as the I/O buffer in RWTS's IOB.
|
|
(B045)
|
|
PT2DIRBF LDA ADRDIRBF ;Get the addr of the directory sec buf
|
|
STA IBBUFP ;in the FM constants table.
|
|
LDA ADRDIRBF+1 ;Store it in RWTS's IOB.
|
|
STA IBBUFP+1
|
|
(B051) RTS
|
|
|
|
(B03A) LDX CURDIRTK ;Enter RWTS driver with (x)/(y) = trk/sec vals.
|
|
LDY CURDIRSC
|
|
LDA #2 ;Write opcode for RWTS.
|
|
(B042) JMP RWTSDRVR ;Call RWTS driver to write the directory sector buffer.
|
|
------------
|
|
|
|
(B052)
|
|
RWTSDRVR .
|
|
.
|
|
(See dis'mbly of RWTS driver using WRITE.)
|
|
.
|
|
.
|
|
(RTS)
|
|
|
|
* Read the T/S list sector into the
|
|
* T/S list buffer. (Need this info
|
|
* so know what sectors to release.)
|
|
(AD53) CLC ;(c) = 0 = 1rst T/S list sec.
|
|
(AD54) ;(c) = 1 = 2nd T/S list sec.
|
|
RDTS4DEL JSR READTS ;Go read in a T/S list sector.
|
|
|
|
* Read T/S list sector.
|
|
(AF5E)
|
|
READTS PHP ;Save (c) denoting if 1rst T/S list or not.
|
|
;(c) = 0 = read 1rst T/S list sec.
|
|
;(c) = 1 = read next T/S list sec.
|
|
(AF5F) JSR CKTSUPDT ;Write T/S list sec buf if updating is
|
|
;required. (If T/S list buf has changed
|
|
;since last read or write, then write it
|
|
;back to the disk so don't overwrite buf
|
|
;and lose information when read the new
|
|
;T/S list sector.)
|
|
|
|
* Check if T/S list requires updating.
|
|
* (ie. Has T/S list buf changed since
|
|
* the last read or write?)
|
|
(AF34)
|
|
CKTSUPDT LDA UPDATFLG
|
|
(AF37) BMI WRITETS ;If bit 7 set, updating is required.
|
|
;NOT APPLICABLE TO THE DELETE FUNCTION.
|
|
(AF39) RTS
|
|
|
|
(AF62) JSR SETTSIOB ;Prepare RWTS's IOB for READING a T/S list.
|
|
|
|
* Prepare RWTS's IOB for reading
|
|
* or writing the T/S list sector.
|
|
(AF4B)
|
|
SETTSIOB LDA TSBUFFM ;Get adr of the T/S list buf from the FM
|
|
STA IBBUFP ;parameter list & designate T/S list buf
|
|
LDA TSBUFFM+1 ;as the I/O buffer in RWTS's IOB.
|
|
STA IBBUFP+1
|
|
LDX CURTSTRK ;Set (x)/(y) = trk/sec of current T/S list.
|
|
LDY CURTSSEC
|
|
(AF5D) RTS
|
|
|
|
(AF65) JSR SELTSBUF ;Select the T/S list buffer.
|
|
|
|
* Point A4L/H at the T/S list sector buffer.
|
|
(AF0C)
|
|
SELTSBUF LDX #2 ;Index for T/S list buf.
|
|
(AF0E) BNE PT2FMBUF ;ALWAYS.
|
|
|
|
(AF12)
|
|
PT2FMBUF LDA WRKBUFFM,X ;Get address of the desired buffer from
|
|
STA A4L ;the FM parameter list & put it in the
|
|
LDA WRKBUFFM+1,X ;A4L/H pointer.
|
|
STA A4L+1
|
|
(AF1C) RTS
|
|
|
|
(AF68) PLP ;Get saved (c) back from stack.
|
|
(AF69) BCS RDNXTTS ;If (c) = 1, already read first T/S list
|
|
;sec, so go read next one.
|
|
;(Not applicable on first entry cause (c) = 0).
|
|
|
|
* Read first T/S list sector.
|
|
* (Carry was clear.)
|
|
(AF6B)
|
|
RDFIRSTS LDX FIRSTSTK ;Set (x)/(y)=trk/sec of first T/S list sec.
|
|
LDY FIRTSSEC
|
|
(AF71) JMP RDTSLST ;Go read T/S list sector into buffer.
|
|
------------
|
|
|
|
* Read the next T/S list sector.
|
|
* (Carry was set.)
|
|
(AF74)
|
|
RDNXTTS LDY #1 ;Index into the T/S list buffer.
|
|
LDA (A4L),Y ;Trk for link to next T/S list sector.
|
|
(AF78) BEQ TSLNKZRO ;Link zeroed out so there are no more
|
|
;T/S list secs for this file.
|
|
(AF7A) TAX ;(x) = next T/S list sec number.
|
|
INY
|
|
LDA (A4L),Y ;Sector # for link to next T/S list sec.
|
|
TAY ;(y) = next T/S list sector number.
|
|
(AF7F) JMP RDTSLST ;Go read in the next T/S list.
|
|
-------------
|
|
|
|
* The T/S link zeroed out so we must decide
|
|
* if we got an error or not. (That is, do
|
|
* we want to create another T/S list?)
|
|
(AF82)
|
|
TSLNKZRO LDA OPCODEFM ;Check if reading or writing to see
|
|
CMP #4 ;if we want to add another T/S list.
|
|
(AF87) BEQ UPDATETS ;Writing - so go update link.
|
|
;(Never take with DELETE function.)
|
|
(AF89) SEC ;We were reading and the link zeroed out,
|
|
(AF8A) RTS ;so return with (c) = 1 to generate an error.
|
|
============ ;(Remember, we previously set the return
|
|
;code to a default value for a file-not-found
|
|
;error.)
|
|
|
|
* Subroutine to read/write T/S list sector.
|
|
(AFB5)
|
|
RDTSLST LDA #1 ;Read opcode for RWTS.
|
|
|
|
* Code common to read/write T/S list.
|
|
(AFB7)
|
|
RDWRTS STX CURTSTRK ;New T/S list sector trk/sec values (x)/(y)
|
|
STY CURTSSEC ;become current T/S list trk/sec values.
|
|
(AFBD) JSR RWTSDRVR ;Call RWTS driver to read/write current T/S
|
|
;list.
|
|
|
|
* Read or write the current T/S list.
|
|
(B052)
|
|
RWTSDRVR .
|
|
.
|
|
(See dis'mbly of RWTS driver using READ.)
|
|
.
|
|
.
|
|
(RTS)
|
|
|
|
* Update the FM work area
|
|
* (not in DOS buffer chain).
|
|
(AFC0) LDY #5 ;Offset into current T/S list buffer.
|
|
LDA (A4L),Y ;Get & save the relative sector number of
|
|
(AFC4) STA RELFIRST ;the first data sector that can be described in this
|
|
;T/S list. (Possible values are: $0000, $007A,
|
|
;2*$007A, 3*$007A OR 4*$007A.)
|
|
(AFC7) CLC ;Add the maximum # of data secs that can be described
|
|
ADC MXSCURTS ;in this T/S list.
|
|
STA RELASTP1 ;Store maximum relative sector number (plus 1) of
|
|
INY ;the last data sector that can be described in this list.
|
|
LDA (A4L),Y
|
|
STA RELFIRST+1
|
|
ADC MXSCURTS+1
|
|
(AFD7) STA RELASTP1+1 ;(RELASTP1/+1 = $0000, $007A, 2*$007A,
|
|
;4*$007A or 5*$007A.)
|
|
(AFDA) CLC ;Return with "no error" signal.
|
|
(AFDB) RTS
|
|
|
|
(AD57) BCS DONEDEL ;Branch if just read the last T/S list
|
|
;sector associated with this file.
|
|
(AD59) JSR SELTSBUF ;Point A4L/H at the T/S list sector
|
|
|
|
|
|
* Point A4L/H at the T/S list sector buffer.
|
|
(AF0C)
|
|
SELTSBUF LDX #2 ;Index for T/S list buf.
|
|
(AF0E) BNE PT2FMBUF ;ALWAYS.
|
|
|
|
(AF12)
|
|
PT2FMBUF LDA WRKBUFFM,X ;Get address of the desired buffer from
|
|
STA A4L ;the FM parameter list & put it in the
|
|
LDA WRKBUFFM+1,X ;A4L/H pointer.
|
|
STA A4L+1
|
|
(AF1C) RTS
|
|
|
|
* Free all the sectors that are listed in
|
|
* the T/S list sector that currently occupies
|
|
* the T/S list sector buffer.
|
|
(AD5C) LDY #12 ;First data sector pair listed is offset 12
|
|
;bytes from the start of the T/S list buf.
|
|
DELFREE STY CURDIRNX ;Set (y) = index to data pair in the
|
|
(AD5E) ;T/S list buffer.
|
|
(AD61) LDA (A4L),Y ;Get trk # of the data sector.
|
|
(AD63) BMI BYPASDEL ;Neg track # is illegal (usually denotes
|
|
;a deleted file). (Can use neg track # as a
|
|
;protection scheme.)
|
|
(AD65) BEQ BYPASDEL ;Trk # of 0 = no more data secs listed in
|
|
;the current T/S list sector.
|
|
(AD67) PHA ;Save trk # of data sector on the stack.
|
|
INY ;Get sec # of data sector.
|
|
LDA (A4L),Y
|
|
TAY ;Condition (y) = sec & (a) = trk for entry
|
|
PLA ;into routines to free up sectors.
|
|
(AD6D) JSR FREESEC ;Free up sectors for the deleted file.
|
|
|
|
* Subroutine to free up a sector
|
|
* in the VTOC TRKMAP.
|
|
(AD89)
|
|
FREESEC SEC ;(c) = 1 so free up present sector when
|
|
;start rotating the assignment map.
|
|
(AD8A) JSR SUB2FREE ;Adjust assignment map to FREE UP SECTORS
|
|
;BY SETTING BIT corresponding to the sector
|
|
;number. Next, merge ASIGNMAP with the
|
|
;appropriate bit map in the VTOC.
|
|
|
|
* Subroutine to free up sectors that were
|
|
* deleted or prematurely assigned but not used.
|
|
*
|
|
* This tricky little routine is easy to
|
|
* understand once you realize that:
|
|
* 1) Unlike the VTOC, ASIGNMAP does not
|
|
* contain any unnecessarily assigned
|
|
* sectors.
|
|
* 2) If the disk was just written to,
|
|
* ASIGNMAP does not house any newly
|
|
* assigned sectors (even if those sectors
|
|
* are necessary or not).
|
|
* 3) Sectors are normally assigned in
|
|
* descending order.
|
|
* 4) The number of ROR's done = number
|
|
* of sectors that need to be assigned.
|
|
* For example: If the last track had never
|
|
* been assigned and only sectors $0F and
|
|
* $0E were needed, then on entry to SUB2FREE,
|
|
* the first two bytes would appear as follows:
|
|
* Sector numbers: CBA98765 43210FED
|
|
* Bit values: 11111111 11111...
|
|
* After the first ROR, the status of sector
|
|
* $0D is determined by the entry status of
|
|
* the carry (c):
|
|
* Sector numbers: DCBA9876 543210FE
|
|
* Bit values: c1111111 111111..
|
|
* On the next ROR, the "CPY SECPERTK"
|
|
* instruction conditions (c) to clear for
|
|
* sector $0E:
|
|
* Sector numbers: EDCBA987 6543210F
|
|
* Bit values: 0c111111 1111111.
|
|
* On the next ROR, the "CPY SECPERTK"
|
|
* instruction conditions (c) to clear for
|
|
* sector $0F:
|
|
* Sector numbers: FEDCBA98 76543210
|
|
* Bit values: 00c11111 11111111
|
|
* When ASIGNMAP is merged with the corresponding
|
|
* TRKMAP in the VTOC, the sectors that were
|
|
* unnecessarily assigned in the VTOC are
|
|
* freed. (Note: When used in the DELETE
|
|
* function, SUB2FREE is repeatedly called
|
|
* up by FREESEC to free one sector at a time.)
|
|
(B2DD)
|
|
SUB2FREE LDX #$FC ;Set index to shift 4 bytes as a unit
|
|
(B2DF) ;(#$FC --> #$FF).
|
|
STNDARD ROR ASIGNMAP-$FC,X ;4 bytes = map for 1 track.
|
|
INX
|
|
BNE STNDARD
|
|
(B2E5) INY ;When (y) = 16, ASIGNMAP is back in
|
|
;standard position.
|
|
(B2E6) CPY SECPERTK ;Condition (c) for next shift.
|
|
BNE SUB2FREE
|
|
ASL ;Trk*4 to index TRKMAP.
|
|
ASL
|
|
TAY
|
|
(B2EE) BEQ SUB2RTN ;Track value of 0 not allowed.
|
|
|
|
* ASIGNMAP now reflects the true sector assignment
|
|
* and is in standard position. Therefore, merge it
|
|
* with the appropriate TRKMAP in the VTOC to free up
|
|
* extra sectors.
|
|
(B2F0) LDX #4
|
|
MERGMAPS LDA ASIGNMAP-1,X
|
|
ORA TRKMAP0+3,Y ;Do the merge.
|
|
STA TRKMAP0+3,Y
|
|
DEY ;Reduce indices.
|
|
DEX
|
|
BNE MERGMAPS
|
|
SUB2RTN RTS
|
|
(B2FF)
|
|
|
|
(AD8D) LDA #0 ;Zero out ASIGNSEC, ASIGNTRK & ASIGNMAP
|
|
LDX #5 ;(6 bytes) in the work area.
|
|
RELEASEC STA ASIGNSEC,X
|
|
DEX
|
|
BPL RELEASEC
|
|
(AD97) RTS
|
|
|
|
(AD70)
|
|
BYPASDEL LDY CURDIRNX ;Set (y) to index the first data pair.
|
|
INY ;Kick up (y) to point at next data pair.
|
|
INY
|
|
(AD75) BNE DELFREE ;If (y) < > 0, then never ran off the end of
|
|
;the T/S list buff yet, so go check if more
|
|
;data pairs to do.
|
|
|
|
* Free up the sector that contains
|
|
* the T/S list sector.
|
|
(AD77) LDA CURTSTRK ;Trk # of current T/S list sec.
|
|
LDY CURTSSEC ;Sec # of current T/S list sec.
|
|
(AD7D) JSR FREESEC ;Go free up the T/S list sec.
|
|
|
|
* Subroutine to free up a sector
|
|
* in the VTOC TRKMAP.
|
|
(AD89)
|
|
FREESEC SEC ;(c) = 1 so free up present sector when
|
|
;start rotating the assignment map.
|
|
(AD8A) JSR SUB2FREE ;Adjust assignment map to FREE UP SECTORS
|
|
;BY SETTING BIT corresponding to the sector
|
|
;number. Next, merge ASIGNMAP with the
|
|
;appropriate bit map in the VTOC.
|
|
|
|
(B2DD)
|
|
SUB2FREE .
|
|
.
|
|
(See dis'mbly above.)
|
|
.
|
|
.
|
|
(RTS)
|
|
|
|
(AD8D) LDA #0 ;Zero out ASIGNSEC, ASIGNTRK & ASIGNMAP
|
|
LDX #5 ;(6 bytes) in the work area.
|
|
RELEASEC STA ASIGNSEC,X
|
|
DEX
|
|
BPL RELEASEC
|
|
(AD97) RTS
|
|
|
|
(AD80) SEC
|
|
(AD81) BCS RDTS4DEL ;ALWAYS.
|
|
|
|
* Done freeing up all the sectors associated
|
|
* with this file, so now write the modified
|
|
* VTOC back to the disk.
|
|
(AD83)
|
|
DONEDEL JSR WRITVTOC
|
|
|
|
* Write the updated VTOC to the disk.
|
|
(AFFB)
|
|
WRITVTOC LDA #2 ;Write opcode for RWTS.
|
|
|
|
* Common to read/write VTOC.
|
|
(AFFD)
|
|
RDWRVTOC LDY ADRVTOC ;Get the address of the VTOC from the
|
|
STY IBBUFP ;FM constants table and designate it as
|
|
LDY ADRVTOC+1 ;the I/O buffer in RWTS's IOB.
|
|
STY IBBUFP+1
|
|
LDX TRKWA ;Enter RWTS driver with (x)/(y) equal to the
|
|
LDY #0 ;trk/sec values of the VTOC.
|
|
(B00E) JMP RWTSDRVR ;Call RWTS driver to write the directory sector buffer.
|
|
------------
|
|
|
|
(B052)
|
|
RWTSDRVR .
|
|
.
|
|
(See dis'mbly of RWTS driver using WRITE.)
|
|
.
|
|
.
|
|
(RTS)
|
|
|
|
(AD86) JMP GOODFMXT ;Go exit file manager cleanly.
|
|
-----------
|
|
|
|
|
|
* Exit the file manager with or without errors.
|
|
(B35F)
|
|
LNGNOTAV LDA #1
|
|
(B361) BNE BADFMXIT ;ALWAYS.
|
|
|
|
(B373)
|
|
FILENOT LDA #6
|
|
BNE BADFMXIT ;ALWAYS.
|
|
DISKFULL JMP FULLPTCH ;(See dis'mbly of errors.)
|
|
NOP
|
|
FILELOKD LDA #10
|
|
BNE BADFMXIT ;ALWAYS.
|
|
GOODFMXT LDA RTNCODFM
|
|
CLC ;(c) = 0 to signal good operation.
|
|
BCC FMEXIT
|
|
BADFMXIT SEC ;(c) = 1 to signal unsuccessful.
|
|
FMEXIT PHP ;Save status on stack.
|
|
STA RTNCODFM ;Store return code in FM parameter list.
|
|
LDA #0
|
|
STA STATUS
|
|
(B38E) JSR CPYFMWA ;Copy the work area to the work buffer.
|
|
|
|
* Copy the FM work area (non-chain) to
|
|
* the FM work buffer (in DOS chain).
|
|
(AE7E)
|
|
CPYFMWA JSR SELWKBUF ;Select the FM work buffer (in DOS chain).
|
|
|
|
* Point the A4L/H pointer at the FM work buffer.
|
|
(AF08)
|
|
SELWKBUF LDX #0 ;Set index to select work buffer.
|
|
(AF0A) BEQ PT2FMBUF ;ALWAYS.
|
|
|
|
(AF12)
|
|
PT2FMBUF LDA WRKBUFFM,X ;Get address of selected buffer from the
|
|
STA A4L ;FM parameter list & put it in the pointer.
|
|
LDA WRKBUFFM+1,X
|
|
STA A4L+1
|
|
(AF1C) RTS
|
|
|
|
(AE81) LDY #0 ;Initialize index.
|
|
STORWRK LDA FMWKAREA,Y ;Get byte from the FM work area.
|
|
STA (A4L),Y ;Put it in the work buffer.
|
|
INY
|
|
CPY #45 ;45 bytes to copy (0 to 44).
|
|
BNE STORWRK
|
|
(AE8D) RTS
|
|
|
|
(B391) PLP ;Retrieve status of success of operation
|
|
;from the stack.
|
|
(B392) LDX STKSAV ;Adjust stack pointer to force exit to the
|
|
TXS ;caller of the function even if we are
|
|
RTS ;several subroutines deeper than the
|
|
============ ;original entry point. (That is, return to
|
|
;AFTRFUNC ($A6AB) in the FMDRIVER routine
|
|
;($A6A8).)
|
|
|