💾 Archived View for mirrors.apple2.org.za › archive › www.textfiles.com › apple › ANATOMY › t.dos.b2… captured on 2023-01-29 at 11:41:54.

View Raw

More Information

-=-=-=-=-=-=-

	
=====================================

	
FREE UP SECTORS THAT WERE ASSIGNED

	
BUT NOT USED.

	
=====================================




	
WHENEVER, SOMETHING IS WRITTEN TO

	
THE DISK, THE WHOLE TRK IS ALLOCATED

	
IN THE VTOC WHETHER IT IS NEEDED OR

	
NOT.  THERE4, ONCE WE ARE DONE

	
WRITING, GO BACK & FREE UP THE

	
UNNEEDED SECTORS.



FIXMAP LDA ASIGNTRK ;HAS A TRK ALREADY BEEN ASSIGNED?
 BNE FREEXTRA ;YES - GO FREE UP EXTRA SECS.
 RTS ;NO - GO EXIT.

FREEXTRA PHA ;SAVE TRK # ON STK.
 JSR READVTOC ;READ IN THE VTOC.
 LDY ASIGNSEC ;SET (Y) = # OF NEXT SECTOR WHICH
;COULD HAVE BEEN WRITTEN.
 PLA ;GET ASSIGNMENT TRK# BAK FRM STK.
 CLC ;DON'T WANT 2 FREE LAST SEC USED,
;SO CLR (C) HERE SO DON'T FREE IT
;UP WHEN BEGIN ROTATING MAPS IN
;SUB2FREE ROUTINE.
 JSR SUB2FREE ;ADJUST ASIGNMAP TO FREE UP SECS
;BY SETTING BIT CORRESPONDING TO
;THE SEC #.  NEXT, MERGE ASIGNMAP
;WITH THE APPROPRIATE TRK MAP IN
;THE VTOC.
 LDA #0 ;NO MORE DEALLOCATIONS NEEDED.
 STA ASIGNTRK
 JMP WRITVTOC ;WRITE CORRECTED VTOC BACK 2 DSK.



	
================================

	
SUBROUTINE TO FREE UP SECS 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 UNNECESSARILY

	
ASSIGNED SECTORS.

	
2) IF THE DISK WAS JUST WRITTEN

	
TO, ASIGNMAP MAP DOES NOT HOUSE

	
ANY NEWLY ASSIGNED SECS (EVEN

	
IF THOSE SECS ARE NECESSARY OR

	
NOT).

	
3) SECS ARE NORMALLY ASSIGNED

	
IN DESCENDING ORDER.

	
4) # OF ROR'S = # OF SECS THAT

	
NEED TO BE ASSIGNED.

	


	
FOR EX:  IF LAST TRK HAD NEVER

	
BEEN ASSIGNED & ONLY SECS $0F

	
AND $0E WERE NEEDED, THEN ON

	
ENTRY TO SUB2FREE, THE 1RST 2

	
BYTES WOULD APPEAR AS FOLLOWS:

	
SEC NMB: CBA98765 43210FED

	
BIT VAL: 11111111 11111...

	
AFTER THE 1RST ROR, THE STATUS

	
OF SEC $0D IS DETERMINED BY THE

	
ENTRY STATUS OF THE CARRY (C):

	
SEC NMB: DCBA9876 543210FE

	
BIT VAL: C1111111 111111..

	
ON NEXT ROR, THE "CPY SECPERTK"

	
INSTRUC CONDITIONS (C) TO CLR

	
FOR SEC $0E:

	
SEC NMB: EDCBA987 6543210F

	
BIT VAL: 0C111111 1111111.

	
ON NEXT ROR, THE "CPY SECPERTK"

	
INSTRUC CONDITIONS (C) TO CLR

	
FOR SEC $0F:

	
SEC NMB: FEDCBA98 76543210

	
BIT VAL: 00C11111 11111111

	
WHEN ASIGNMAP IS MERGED WITH THE

	
CORRESPONDING TRKMAP IN THE VTOC,

	
THE SECS THAT WERE UNNECESSARILY

	
ASSIGNED IN THE VTOC ARE FREED.

	
(NOTE:  WHEN USED IN THE DELETE

	
FUNCTION, SUB2FREE IS REPEATEDLY

	
CALLED BY FREESEC TO FREE ONE

	
SECTOR AT A TIME.)



SUB2FREE LDX #$FC ;SET INDEX TO SHIFT 4 BYTES AS A
;UNIT (#$FC --> #$FF).
STNDARD ROR ASIGNMAP-$FC,X ;4 BYTES PER MAP FOR @ TRK.
 INX
 BNE STNDARD
 INY ;WHEN (Y) = 16, ASIGNMAP IS BACK
;IN STANDARD POS'N.
 CPY SECPERTK ;CONDITION (C) FOR NEXT SHIFT.
 BNE SUB2FREE
 ASL ;TRK*4 TO INDEX TRKMAP.
 ASL
 TAY
 BEQ SUB2RTN ;TRK VAL OF 0 NOT ALLOWED.


	
ASIGNMAP NOW REFLECTS TRUE SEC

	
ASSIGNMENT & IS IN STANDARD

	
POSITION.  THERE4, MERGE IT

	
WITH THE APPROPRIATE TRKMAP IN

	
THE VTOC TO FREE UP EXTRA SECS.



 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



	
==========================================

	
CALCULATE THE EXACT POSITION OF THE

	
3-BYTE FILE POINTER:

	
==========================================




	
- FILPTSEC = SECTOR OFFSET (IN LOW/HI

	
FORMAT) INTO THE ENTIRE FILE (2 BYTES).

	
- FILPTBYT = BYTE OFFSET INTO THE CURRENT

	
SECTOR (1 BYTE).

	


	
ALL 3 BYTES BYTES DEFINE THE EXACT POS'N

	
OF THE FILE POINTER VIA THE FOLLOWING

	
FORMULA:

	
(REC# * REC LENGTH) + BYTE OFFSET

	
INTO THE RECORD.

	
WHERE:

	
RECNMBFM=RECORD# FROM R-PARAMETER (SET

	
BY USER WHEN USING RANDOM

	
ACCESS FILES OR SIMPLY

	
INCREMENTED WHEN USING OTHER

	
FILE TYPES).

	
RECLENWA=RECORD LENGTH PARSED FROM

	
L-PARAMETER & ASSIGNED WITH

	
THE OPEN CMD (ELSE DEFAULTED

	
TO A SIZE OF 1).

	
BYTOFFFM=OFFSET INTO THE CURRENT RECORD

	
(SET BY USER WHEN USING THE

	
OPEN CMD OR OCCASIONALLY USED

	
WITH SEQUENTIAL FILES AS A

	
B-PARAMETER).

	
NOTE THAT YOU CAN ACTUALLY DIRECTLY

	
ACCESS ANY BYTE IN ANY FILE BY

	
BYPASSING THE COMMAND INTERPRETER AND

	
SETTING THE L-, B- AND R-PARAMETERS

	
HOWEVER YOU WANT.



CALCFPTR LDA RECNMBFM ;PUT RECORD # IN MULTIPLIER AND
 STA FILPTBYT ;ALSO SAVE IT IN THE WORK AREA.
 STA RECNMBWA
 LDA RECNMBFM+1
 STA FILPTSEC
 STA RECNMBWA+1
 LDA #0 ;ZERO OUT HI ORDER BYTE OF SEC
 STA FILPTSEC+1 ;OFFSET INTO THE ENTIRE FILE.


	
CALCULATE:  REC # * REC LENGTH.

	
THIS ROUTINE IS JUST A BASIC

	
MULTPLICATION OF TWO 16-BIT

	
NUMBERS.  IT MAY AT FIRST SEEM

	
CONFUSING BECAUSE FILPTSEC &

	
FILPTBYT ARE USED BOTH FOR HOLDING

	
THE MULTIPLIER (RECORD #) AND PART

	
OF THE PRODUCT RESULT.  HOWEVER,

	
THE BITS OF THE PRODUCTS DON'T GET

	
MIXED UP WITH THE BITS OF THE

	
MULTIPLIER BECAUSE ROLLING IN A

	
PRODUCT BIT ALSO ROLLS OUT THE

	
LAST-USED MULTIPLIER BIT (IE.,

	
THERE IS NO BIT OVERLAP).



 LDY #16 ;16 BITS / ONE 2-BYTE NUMBER.
NMBXLEN TAX ;SAVE PART OF RUNNING PRODUCT.
;(ON 1RST ENTRY, SET (X) = 0.)
 LDA FILPTBYT ;GET (A) = MULTIPLIER.
 LSR ;PUT MULTIPLIER BIT IN CARRY.
 BCS NMBXLEN1 ;IF (C)=1, GO ADD MULTIPLICAND.
 TXA ;(A) = PART OF RUNNING PRODUCT.
 BCC NMBXLEN2 ;ALWAYS, NO USE +ING MULTIPLICAND
;CAUSE BIT IN MULTIPLIER IS A 0
;SO JUST GO SHIFT RUNNING PRODUCT
NMBXLEN1 CLC ;+ MULTIPLICAND 2 RUNNING VERSION
 LDA FILPTSEC+1 ;OF SHIFTED PRODUCT.
 ADC RECLENWA
 STA FILPTSEC+1
 TXA ;SET (A)=LOW BYT OF RUNNING PROD.
 ADC RECLENWA+1
NMBXLEN2 ROR ;SHIFT (AS A UNIT) RUNNING RESULT
 ROR FILPTSEC+1 ;1 BIT RIGHT 4 NEXT TIME AROUND.
 ROR FILPTSEC ;SHIFT LOWER 2 BYTES OF RUNNING
 ROR FILPTBYT ;PRODUCT & AT SAME TIME THROW OUT
;LAST-USED MULTIPLIER BIT.
 DEY ;REDUCE BIT COUNTER.
 BNE NMBXLEN ;TAKE IF NOT USED ALL 16 BITS YET


	
COPY BYTE OFFSET INTO RECORD FROM

	
THE FM PARAMETER LIST TO THE WORK

	
AREA.



 CLC
 LDA BYTOFFFM
 STA BYTOFFWA


	
CALCULATE THE LOWEST ORDER BYTE OF

	
THE FILE POINTER:

	
BYTOFFWA = OFFSET INTO CURRENT RECORD.

	
= BYTE OFFSET INTO RECORD

	
+ (RECORD LENGTH * RECORD #).



 ADC FILPTBYT
 STA FILPTBYT
 LDA BYTOFFFM+1
 STA BYTOFFWA+1
 ADC FILPTSEC
 STA FILPTSEC
 BCC CALCRTS
 INC FILPTSEC+1
CALCRTS RTS


	
RESIDUAL JUNK



 HEX B5 ;GARBAGE LEFT OVER FRM OLD ROUT'N
 RTS ;PRIOR TO PATCH TO CALCFPTR.
;CONSIDER AS FREE SPACE.



	
=================================

	
EXIT FM WITH OR WITHOUT ERRS.

	
=================================



LNGNOTAV LDA #1
 BNE BADFMXIT ;ALWAYS.
RNGERROP LDA #2
 BNE BADFMXIT ;ALWAYS.
RNGERRSB LDA #3
 BNE BADFMXIT ;ALWAYS.
WRITPROT LDA #4
 BNE BADFMXIT ;ALWAYS.
ENDOFDAT LDA #5
 BNE BADFMXIT ;ALWAYS.
FILENOT LDA #6
 BNE BADFMXIT ;ALWAYS.
DISKFULL JMP FULLPTCH
 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.


	
COMMON FM EXIT ROUTINE.

	
NOTE THAT ROUTINE IS EXITED BY

	
RESETTING THE STACK POINTER.

	
USUALLY RETURNS TO CALLER OF THE

	
FUNCTION (IE. NORMALLY RETURNS TO

	
AFTRFUNC, $A6AB) IN THE FMDRIVER

	
ROUTINE ($A6A8).)  HOWEVER, THERE

	
IS ONE EXCEPTION.  THE APPEND CMD

	
HNDLR (CMDAPPND, $A298) MAY CALL

	
THIS ROUTINE SEVERAL TIMES.  MOST

	
OF THE TIME, EXECUTION RTNS TO

	
AFTRFUNC.  HOWEVER, THE LAST TIME

	
FMEXIT IS CALLED, THE CONTENTS OF

	
STKSAV ($B39B) ARE ALTERED BEFORE

	
FMEXIT IS ENTERED.  THIS FORCES

	
AN EXIT TO CALLER OF APPEND CMD

	
HNDLR (RATHER THAN TO CALLER OF

	
FUNCTION HNDLR).  IN THIS LATER

	
INSTANCE, EXECUTION ACTUALLY RTNS

	
TO AFTRCMD ($A17D) LOCATED IN THE

	
COMMAND PARSING & PROCESSING ROUTINES.




FMEXIT PHP
 STA RTNCODFM ;STORE RTN CODE IN FM PARM LIST.
 LDA #0 ;AVOID THAT INFAMOUS $48 BUG.
 STA STATUS
 JSR CPYFMWA ;COPY WORK AREA TO WORK BUFFER.
 PLP ;RETRIEVE STATUS OF SUCCESS OF
;OPERATION BACK OFF STK.
 LDX STKSAV ;ADJUST STK POINTER TO FORCE EXIT
 TXS ;TO CALLER EVEN IF SEVERAL
  RTS ;SUBRT'NS DEEPER THAN ORIG ENTRY.



	
=================================

	
FILE MANAGER SCRATCH SPACE.

	
($B397 - $B3A3)

	
=================================



CURDIRTK DS 1 ;TRK# OF CURRENT DIRECTORY SEC.
CURDIRSC DS 1 ;SEC# OF CURRENT DIRECTORY SEC.
WABUFADR HEX 0000 ;UNUSED ($B399-$B39A).
STKSAV DS 1 ;SECOND STACK POINTER SAVE AREA.
;USED TO RESET THE STACK TO FORCE
;EXECUTION TO RTN TO A DESIRED
;ROUTINE.  (NORMALLY RETURNS TO
;AFTRFUNC ($A6AB) AFTR @ FUNCTION
;IS CALLED. HOWEVER, ALSO USED BY
;THE APPEND CMD 2 FORCE EXECUTION
;TO RTN TO AFTRCMD ($A17D).)
;P.S.  DON'T CONFUSE STKSAV WITH
;THE 1RST STACK POINTER SAVE AREA
;(STKSAVED, $AA59).
CURDIRNX DS 1 ;BYTE OFFSET OF FILE DESCRIPTION
;ENTRY INTO CURRENT DIREC SEC.
SCRNSRCH DS 1 ;- CATALOG SCRN LINE COUNTER.
;- DESCENDING CNTR 4 # OF SRCHS
;  DONE 2 LOCATE A MATCHING NAME
;  OR EMPTY SPACE FOR A NEW FILE
;  DESCRIP ENTRY IN DIRECTORY SEC
;  (SEARCH1 = 1, SEARCH2 = 0).
;- OFFSET OF DAT PR FROM START OF
;  A GIVEN T/S LIST.
TRK0YET DS 2 ;ASSIGNMENT FLAG = SIGNAL IF TRK0
;ENCOUNTERED YET (ONLY 1RST BYTE
;USED):
;   $00=TRK0 NOT ENCOUNTERED YET.
;   $01 = TRK0 ENCOUNTERED.
;(USED TO SEE IF ENTIRE DISK HAS
;BEEN SCANNED WHEN LOOKING 4 FREE
;SECS TO ASSIGN.)
LOKUNMSK = TRK0YET ;LOCK/UNLOCK MASK ($80/$00).
FRETKMSK HEX 0000FFFF ;4-BYTE MASK USED BY INIT FUNC'N
;TO FREE AN ENTIRE TRACK.



	
=================================

	
CONVERSION TABLE FOR PRVOLNMB.

	
($B3A4 - $B3A6)

	
=================================



BASETEN HEX 010A64 ;10^0=0, 10^1=10, 10^2=100.



	
=================================

	
CHARACTER CODE FILE TYPE SYMBOLS

	
USED BY THE CATALOG ROUTINE.

	
($B3A7 - $B3AE)

	
=================================



FTYPETBL ASC "TIABSRAB" ;TEXT, INTEGER, APPLESOFT, BINARY
;S-TYPE, R(ELOCATABLE)-TYPE,
;A-TYPE, B-TYPE.  THESE CODES ARE
;FREQUENTLY CHANGED BY HACKERS.)



	
=================================

	
DISK VOLUME SPELLED BACKWARDS.

	
($B3AF - $B3BA)

	
=================================



DSKVOLUM ASC " EMULOV KSID" ;THESE CHRS ARE OFTEN CHANGED
;TO PERSONALIZE A CATALOG.



	
=================================

	
VOLUME TABLE OF CONTENTS (VTOC)

	
BUFFER ($B3BB - $B4BA).

	
=================================



VTOCBUFF DS 1 ;UNUSED ($B3BB).
;REFERENCE FOR START OF TABLE.
FIRDIRTK DS 1 ;TRK# OF 1RST DIRECTORY SECTOR.
FIRDIRSC DS 1 ;SEC# OF 1RST DIRECTORY SECTOR.
VERSION HEX 03 ;DOS VERSION RELEASE NUMBER.
 DS 2 ;UNUSED ($B3BF-$B3C0).
VOLUSED DS 1 ;DISK VOL# (NORMALLY, $FE).
 DS 32 ;UNUSED ($B3C2-$B3E1).
MXIN1TSL HEX 7A ;MAX # OF SECS THAT CAN BE LISTED
;IN A T/S LIST SEC ($7A, #122).
 DS 8 ;UNUSED ($B3E3-$B3EA).
NXTRKUSE DS 1 ;NEXT TRACK TO ASSIGN.
DRECTION DS 1 ;TRK ASGNMENT DIRECT'N (+1 OR -1)
 DS 2 ;UNUSED ($B3ED-$B3EE).
TKPERDSK HEX 23 ;TRKS/DISK (#35).
;AFTER DRIVE ADJUSTMENT, VALUE IN
;TKPERDSK CAN BE ALTERED 2 ENABLE
;THE USE OF AN EXTRA TRK ON DISK.
SECPERTK HEX 10 ;SECS/TRK ($10, #16, $00 --> $0F)
BYTPERSC HEX 0001 ;BYTES/SECTOR ($0100, #256).



	
------------------------------------

	
TRACK/SECTOR MAPS IN VTOC.

	
($B3F3 - $B47E)

	
------------------------------------




	
MAPS OF SECTOR USAGE ON EACH TRK.

	
EACH TRK IS REPRESENTED BY FOUR

	
BYTES.  THE BITS IN THESE BYTES

	
DEFINE THE SECTOR USAGE BY THE

	
FOLLOWING CONVENTION:

	
SET BIT = FREE SECTOR.

	
CLEAR BIT = USED SECTOR.

	
1RST BYTE:  FEDC BA98

	
2ND BYTE:  7654 3210

	
(THE 3RD & 4TH BYTES ASSOCIATED

	
WITH @ TRK ARE WASTED.  THESE BYTES

	
ARE WASTED BECAUSE THEY ARE WRITTEN

	
OVER BY DOS BUT NOT ACTUALLY USED

	
FOR ANYTHING.  THERE4 THEY ARE NOT

	
READILY AVAILABLE TO THE ASSEMBLY

	
LANGUAGE PROGRAMMER THAT IS IN

	
DESPERATE NEED OF AN AVAIABLE HOLE

	
IN DOS.)



TRKMAP0 HEX 00000000 ;$B3F3: TRK0 (DOS IMAGE).
TRKMAP1 HEX 00000000 ;$B3F7: TRK1 (DOS IMAGE).
TRKMAP2 HEX 00000000 ;$B3FB: TRK2 (SECS 0 TO 4 USD FOR
;DOS IMAGE.  REST OF SECS ARE
;SET ASIDE BUT NOT USED BY DOS.
;THEY ARE FREE TO THE USER AFTER
;ALTERING TRKMAP2, USING RWTS
;DIRECTLY OR ALTERING THE BOOT.)
TRKMAP3 DS 4 ;$B3FF: TRK 3
TRKMAP4 DS 4 ;$B403: TRK4
TRKMAP5 DS 4 ;$B407: TRK5
TRKMAP6 DS 4 ;$B40B: TRK6
TRKMAP7 DS 4 ;$B40F: TRK7
TRKMAP8 DS 4 ;$B413: TRK8
TRKMAP9 DS 4 ;$B417: TRK9
TRKMAP10 DS 4 ;$B41B: TRK$0A
TRKMAP11 DS 4 ;$B41F: TRK$0B
TRKMAP12 DS 4 ;$B423: TRK$0C
TRKMAP13 DS 4 ;$B427: TRL$0D
TRKMAP14 DS 4 ;$B42B: TRK$0E
TRKMAP15 DS 4 ;$B42F: TRK$0F
TRKMAP16 DS 4 ;$B433: TRK $10
TRKMAP17 DS 4 ;$B437: TRK$11 (DIRECT/VTOC).
TRKMAP18 DS 4 ;$B43B: TRK$12
TRKMAP19 DS 4 ;$B43F: TRK$13
TRKMAP20 DS 4 ;$B443: TRK$14
TRKMAP21 DS 4 ;$B447: TRK$15
TRKMAP22 DS 4 ;$B44B: TRK$16
TRKMAP23 DS 4 ;$B44F: TRK$17
TRKMAP24 DS 4 ;$B453: TRK$18
TRKMAP25 DS 4 ;$B457: TRK$19
TRKMAP26 DS 4 ;$B45B: TRK$1A
TRKMAP27 DS 4 ;$B45F: TRK$1B
TRKMAP28 DS 4 ;$B463: TRK$1C
TRKMAP29 DS 4 ;$B467: TRK$1D
TRKMAP30 DS 4 ;$B46B: TRK$1E
TRKMAP31 DS 4 ;$B46F: TRK$1F
TRKMAP32 DS 4 ;$B473: TRK$20
TRKMAP33 DS 4 ;$B477: TRK$21
TRKMAP34 HEX FFFF0000 ;$B47B: TRK$22



	
---------------------------------

	
UNUSED PART OF VTOC

	
($B47F - $B4BA)

	
---------------------------------



 DS 60 ;UNUSED ($B47F-$B4BA).



	
=================================

	
DIRECTORY SECTOR BUFFER.

	
($B4BB - $B5BA)

	
=================================



DIRECBUF HEX 00 ;UNUSED-REFERENCE 4 START OF BUF.
DIRLNKTK DS 1 ;TRK OF NEXT DIRECTORY SECTOR.
DIRLNKSC DS 1 ;SECTOR OF NEXT DIRECTORY SECTOR.
 DS 8 ;UNUSED ($B4BC-$B4C5).



	
---------------------------------

	
FILE DESCRIPTION ENTRIES.

	
($B4C6 - $B5BA)

	
---------------------------------



FIL1TSTK DS 1 ;FILE1: T/S LIST TRK ($B4C6)
FIL1TSSC DS 1 ;       T/S LIST SEC ($B4C7)
FIL1TYPE DS 1 ;       FILE TYPE ($B4C8)
FIL1NAME DS 30 ;       NAME ($B4C9-$B4E6)
FIL1SIZE DS 2 ;       SIZE ($B4E7-$B4E8)

FIL2TSTK DS 1 ;FILE2: T/S LIST TRK ($B4E9)
FIL2TSSC DS 1 ;       T/S LIST SEC ($B4EA)
FIL2TYPE DS 1 ;       TYPE ($B4EB)
FIL2NAME DS 30 ;       NAME ($B4EC-$B509)
FIL2SIZE DS 2 ;       SIZE ($B50A-$B50B)

FIL3TSTK DS 1 ;FILE3: T/S LIST TRK ($B50C)
FIL3TSSC DS 1 ;       T/S LIST SEC '$B50D)
FIL3TYPE DS 1 ;       TYPE ($B50E)
FIL3NAME DS 30 ;       NAME ($B50F-$B52C)
FIL3SIZE DS 2 ;       SIZE ($B52D-$B52E)

FIL4TSTK DS 1 ;FILE4: T/S LIST TRK ($B52F)
FIL4TSSC DS 1 ;       T/S LIST SEC ($B530)
FIL4TYPE DS 1 ;       TYPE ($B531)
FIL4NAME DS 30 ;       NAME ($B532-$B54F)
FIL4SIZE DS 2 ;       SIZE ($B550-$B551)

FIL5TSTK DS 1 ;FILE5: T/S LIST TRK ($B552)
FIL5TSSC DS 1 ;       T/S LIST SEC ($B553)
FIL5TYPE DS 1 ;       TYPE ($B554)
FIL5NAME DS 30 ;       NAME ($B555-$B572)
FIL5SIZE DS 2 ;       SIZE ($B573-$B574)

FIL6TSTK DS 1 ;FILE6: T/S LIST TRK ($B575)
FIL6TSSC DS 1 ;       T/S LIST SEC ($B576)
FIL6TYPE DS 1 ;       TYPE ($B577)
FIL6NAME DS 30 ;       NAME ($B578-$B595)
FIL6SIZE DS 2 ;       SIZE ($B596-$B597)

FIL7TSTK DS 1 ;FILE7: T/S LIST TRK ($B598)
FIL7TSSC DS 1 ;       T/S LIST SEC ($B599)
FIL7TYPE DS 1 ;       TYPE ($B59A)
FIL7NAME DS 30 ;       NAME ($B59B-$B5B8)
FIL7SIZE DS 2 ;       SIZE ($B5B9-$B5BA)



	
=================================

	
FILE MANAGER PARAMETER LIST.

	
($B5BB - $B5D0)

	
=================================



OPCODEFM DS 1 ;FM OPERATION CODE.
SUBCODFM DS 1 ;FM OPERATION SUBCODE.
RECNMBFM DS 2 ;FM PARM LST VERSION OF RECORD #.
;(USUALLY 1 LESS THAN RECNMBWA.)
;(SEE DESCRIPTION OF THE RECORD
;NUMBER GIVEN IN THE WORK AREA
;LISTED BELOW.)
BYTOFFFM DS 2 ;BYTE OFFSET INTO RECORD.
LEN2RDWR DS 2 ;LENGTH TO READ OR LENGTH-1
;TO WRITE.  (INIT VAL & COUNTER).
;ALSO USED AS A TEMPORARY BUF TO
;TRANSFER ADDR & LENGTH BYTES TO
;ONEIOBUF BUF WHEN USING THE
;WRITE-ONE-BYTE AND READ-ONE-BYTE
;SUBFUNCTIONS.
CURIOBUF DS 2 ;ADDR OF CURRENT I/O BUFFER.
RTNCODFM DS 1 ;RETURN CODE.  (CONTRARY TO WHAT
;SOME ARTICLES SUGGEST, THE VALUE
;IN THIS BYTE IS ONLY RELEVANT IF
;AN ERROR OCCURS.)
 DS 1 ;UNUSED ($B5C6).
WRKBUFFM DS 2 ;PTS TO WORK BUF (IN DOS CHAIN).
TSBUFFM DS 2 ;PTS TO T/S LIST SEC BUF (CHAIN).
DATBUFFM DS 2 ;PTS TO DATA SECTOR BUF (CHAIN).
NXTNAME DS 2 ;PTS TO NEXT DOS NAME BUFFER IN
;CHAIN. (SET UP, BUT NOT USED.)
 DS 2 ;UNUSED ($B5CF-$B5D0).


FMPRMLST = OPCODEFM ;START OF FM PARAMETER LIST.

FIRDOSPG = OPCODEFM ;CONTAINS 1RST PAGE# OF DOS WHEN
;WRITING DOS IMAGE DURING INIT.

RECLENFM = RECNMBFM ;FM PARM LIST VERSION OF THE
;RECORD LENGTH.  (SEE DESCRIPTION
;OF RECORD LENGTH DESCRIBED IN
;THE WORK AREA LISTING BELOW.)
RENAMBUF = RECLENFM ;PTS 2 BUFFER CONTAINING NEW FILE
;NAME.  (USED IN RENAME CMD.)
VOLFM = BYTOFFFM ;VOLUME# WANTED.
DRVFM = BYTOFFFM+1 ;DRIVE# WANTED.

SLOTFM = LEN2RDWR ;SLOT NUMBER.
FILTYPFM = LEN2RDWR+1 ;FILE TYPE CODE (INCLUDING THE
;LOCKED/UNLOCKED STATUS).
FNAMBUFM = CURIOBUF ;FILE NAME ADDRESS.
ONEIOBUF = CURIOBUF ;A ONE-BYTE I/O BUFFER.



	
=================================

	
FILE MANAGER WORK AREA.

	
($B5D1 - $B5FF)

	
(DON'T CONFUSE WITH THE VARIOUS

	
WORK BUFFERS CONTAINED IN THE

	
CHAIN OF DOS BUFFERS.)

	
=================================



FMWKAREA DS 1 ;SIMPLY USED FOR REFERENCE POINT.

FIRSTSTK = FMWKAREA ;TRK# OF 1RST T/S LIST SEC.
FIRTSSEC DS 1 ;SEC # OF 1RST T/S LIST SEC.
CURTSTRK DS 1 ;TRK# OF CURRENT T/S LIST SEC.
CURTSSEC DS 1 ;SEC# OF CURRENT T/S LIST SEC.
UPDATFLG DS 1 ;FLAG TO UPDATE DIFFERENT TYPES
;OF SECTORS:
; $02=LAST OPERATION WAS A WRITE.
; $20=VTOC NEEDS UPDATING.
; $40=DATA SEC NEEDS UPDATING.
; $80=T/S LST SEC NEEDS UPDATING.
CURDATRK DS 1 ;TRK# OF CURRENT DATA SECTOR.
CURDATSC DS 1 ;SEC# OF CURRENT DATA SECTOR.
SECNXD1R DS 1 ;OFFSET OF FILE DESCRIPTION FROM
;THE VERY FIRST DIRECTORY SEC.
BYTNXD1R DS 1 ;OFFSET OF FILE DESCRIPTION INTO
;THE CURRENT DIRECTORY SEC.
MXSCURTS DS 2 ;MAXIMUM # OF SECS THAT CAN BE
;LISTED IN A T/S LIST.
RELFIRST DS 2 ;RELATIVE SEC # (IN RELATION TO
;THE ENTIRE FILE) OF THE FIRST
;DATA SEC THAT IS (OR CAN BE)
;LISTED IN THE CURRENT T/S LIST.
;(POSSIBLE VALS ARE:$0000, $007A,
;2*$007A, 3*$007A OR 4*$007A.)
RELASTP1 DS 2 ;ONE GREATER THAN THE MAXIMUM
;RELATIVE SEC# (IN RELATION 2 THE
;ENTIRE FILE) OF THE LAST DAT SEC
;THAT CAN POSSIBLY BE DESCRIBED
;IN THE CURRENT T/S LIST.
;(POSSIBLE VALUES ARE: $007A,
;2*$007A, 3*$007A, 4*$007A AND
;5*$007A.)
RELPREV DS 2 ;RELATIVE SEC# (IN RELATION 2 THE
;ENTIRE FILE) OF THE LAST DAT SEC
;THAT WAS READ OR WRITTEN.
;(POSSIBLE VAL ARE: $0000, $007A,
;2*$007A, 3*$007A OR 4*$007A.)
SECSIZWA HEX 0001 ;BYTES/SECTOR (#256, $00-$FF).


	
--- FILE POINTER ---

	
(3 BYTES)


FILPTSEC DS 2 ;SECTOR OFFSET OF PTR (2 BYTES).
FILPTBYT DS 1 ;BYTE OFFSET PORTION OF POINTER.

WASTEBYT DS 1 ;WEIRD FLG USED BY THE APPEND CMD
;(VIA RSETPTRS, $B6B3) WHEN
;BACKING UP THE FILE POINTER AND
;TESTED (IN APNDPTCH, $B692)
;WHENEVER AN OUT-OF-DATA ERROR IS
;ENCOUNTERED.
RECLENWA DS 2 ;RECORD LENGTH.
RECNMBWA DS 2 ;CURRENT RECORD NUMBER.
BYTOFFWA DS 2 ;CURRENT BYTE OFFSET INTO RECORD.
;- RANDOM ACCESS TXT FILES HAVE A
;  FIXED RECORD LNGTH ASSIGNED BY
;  THE USER.
;- SEQUENTIAL TEXT AND APPLESOFT
;  FILES HAVE A RECORD LENGTH OF
;  ONE.
;- DURING A LOAD OR BLOAD, APPLE-
;  SOFT OR BINARY FILES ARE
;  CONSIDERED TO BE COMPOSED OF A
;  COLLECTION OF ONE-BYTE LONG
;  RECORDS.
;- WHEN SAVING OR BSAVING HOWEVER
;  THESE FILES ARE TREATED AS IF
;  THEY CONSIST OF A SINGLE VERY
;  LONG RECORD.
FILENSEC DS 2 ;FILE LENGTH IN SECTORS.
ASIGNSEC DS 1 ;NEXT SECTOR TO ASSIGN.
ASIGNTRK DS 1 ;NEXT TRK TO ASSIGN.
ASIGNMAP DS 4 ;4-BYTE MAP OF SEC USAGE ON THE
;TRK BEING ASSIGNED.
FILTYPWA DS 1 ;FILE TYPE CODE (INCLUDING THE
;LOCKED OR UNLOCKED STATUS).
SLOT16WA DS 1 ;SLOT*16.
DRVWA DS 1 ;DRIVE NUMBER.
VOLWA DS 1 ;1'S COMPLEMENT OF VOLUME NUMBER.
TRKWA DS 1 ;TRACK NUMBER.
 HEX 0000000000 ;UNUSED ($B5FB-$B5FF).



	
=================================

	
IMAGE OF BOOT1 ($B600-$B6FF)

	
=================================




	
- STORED ON TRK0/SEC0.

	
- READ IN AT $800-$8FF BY DISK CONTROLLER ROM (BOOT0).

	
- EXECUTION BEGINS AT $0801 & USES THE CONTROLLER'S READ-

	
SECTOR SUBROUTINE (BTRDSEC, $CS00, WHERE S = SLOT # OF

	
CARD) TO READ IN TRK0/SEC9 DOWN TO TRK0/SEC1 (THAT IS,

	
$BFFF ----> $B600).




	
NOTE:  IN ORDER TO GENERATE AN ACCURATE SYMBOL TABLE THAT

	
CAN BE APPLIED TO BOTH THE FORMATTED AND LINEAR DIS-

	
ASSEMBLIES, AND BECAUSE DIFFERENT ASSEMBLERS VARY IN

	
THEIR ABILITIES TO ACCEPT CERTAIN OBJECT VALUES OR RE-ORG

	
DURING ASSEMBLY, THE FOLLOWING SPECIAL LABEL SYSTEM HAS

	
BEEN CREATED:

	
IMAGE LBL/ADR   EXECUTION LBL/ADR       COMMENTS

	
---------------  -----------------  --------------------

	
SEC2RDB6, $B600  SEC2RDB08, $800    ;DEFINES # OF SECS 2

	
;BE READ IN BY BOOT0

	
BT1EXCB6, $B601  BT1EXC08, $801     ;START BT1 EXECUTION

	
;BOOT0 JMPS TO HERE.

	
SKPRELB6, $B61F  SKPREL08, $81F     ;TARGET LBL 4 BRNCH.

	
PRP4B2B6, $B639  PRP4B208, $839     ;TARGET LBL 4 BRNCH.

	
IMG8FD, $B6FD  BT1LDADR, $8FD     ;BOOT1 LOAD ADDRESS.

	
;VARIES FROM $B600 2

	
;$BF00.  EVENTUALLY

	
;PTS 2 START BOOT2

	
;($B700).

	
IMG8FF, $B6FF  BT1PG2RD, $8FF     ;CONTAINS # OF SECS

	
;TO READ IN WHEN

	
;EXECUTING BOOT1.

	
;ALSO DOUBLES AS

	
;LOGICAL SEC #.

	
;VARIES FROM:

	
;$09 --> $00 --> $FF.

	
AS INDICATED ABOVE, SEC2RD08 ($800) DEFINES # OF SECS

	
TO BE READ IN BY BOOT0.  THIS VALUE IS NORMALLY $01

	
(MEANING READ ONLY SEC0 OF TRK0).  HOWEVER, YOU CAN ZAP

	
TRK0/SEC0/OFFSET0 WITH A LARGER VALUE ($01 TO $10) TO

	
READ IN MORE SECS FROM TRK0.  ALSO NOTE THAT MOST

	
REFERENCES SAY THAT SEC2RD08 NORMALLY CONTAINS A "$00"

	
(RATHER THAN A "$01").  BECAUSE THE TEST AT $CS56 USES

	
THE CARRY, EITHER VAL WILL CAUSE ONLY 1 SEC 2 BE READ IN

	
HOWEVER, "$01" IS THE VALUE USED BY DOS.  (CONFUSION MAY

	
STEM FROM THE FACT THAT APPLESOFT LATER STORES A $00 IN

	
$800.)



SEC2RDB6 HEX 01 ;IMAGE OF SEC2RD08.  DENOTES # OF
;SECS TO BE READ FROM TRK0 DURING
;BOOT0.

BT1EXCB6 LDA PT2BTBUF+1 ;IMAGE OF BT1EXC08. GET NEXT PAGE
;TO BE READ IN.
 CMP #$09 ;IS IT PAGE 9 (IE. 1RST PAGE READ
;BY BOOT1)?
 BNE SKPRELB6 ;NO - ALREADY USED BY BOOT1 TO
;READ PAGE9, SO SKIP POINTER
;INITIALIZATION GIVEN BELOW.


	
INITIALIZE THE POINTER (PTR2RDSC)

	
TO POINT AT BOOT0'S READ SECTOR

	
SUBROUTINE (BTRDSEC, $CS5C;

	
WHERE S=SLOT#, NORMALLY $C65C).



 LDA SLT16ZPG ;(A) = SLOT*16 FROM ZERO PAGE.
 LSR ;DIVIDE BY 16.
 LSR
 LSR
 LSR
 ORA #$C0 ;MERGE WITH $C0 TO GET $CS, WHERE
;S=SLOT#.
 STA PTR2RDSC+1 ;STORE HI BYTE OF CONTROLLER'S
;READ-SECTOR SUBROUTINE ADDR.
 LDA #<BTRDSEC ;GET LOW BYTE OF SUBRTN ADR.
 STA PTR2RDSC ;(LOW BYTE IS A CONSTANT (#$5C) &
;IS THERE4 NOT VARIABLE WITH SLOT
;USED (AS IS HI BYTE).)



	
READ IN 9 SECTORS REPRESENTED BY

	
TRK0/SEC9 DOWN TO TRK0/SEC1 INTO

	
$BFFF TO $B600.  NOTE THAT THE

	
SECS ARE READ IN FROM HIGHER TO

	
LOWER MEMORY. THESE SECS CONTAIN

	
THE IMAGE OF BOOT1, PART OF THE

	
FILE MANAGER AND ALMOST ALL OF

	
RWTS & ITS ASSOCIATED ROUTINES.





	
CALCULATE THE TARGET ADDR FOR

	
THE FIRST SECTOR TO BE READ IN.



 CLC
 LDA BT1LDADR+1 ;CONTAINS $B6 ON 48K SLAVE.
 ADC BT1PG2RD ;CONTAINS #09 ON 48K SLAVE.
 STA BT1LDADR+1 ;(A) = $BF ON 48K SLAVE.


	
DETERMINE # OF PAGES (SECS) LEFT

	
2 READ, PHYSICAL SECTOR# & TARGET

	
ADDRESS.  THEN, GO READ IN THE

	
NEXT SECTOR.



SKPRELB6 LDX BT1PG2RD ;IMAGE OF SKRPREL08 ($81F).
;(X)=PAGES LEFT 2 READ (MINUS 1).
;(ALSO DOUBLES AS LOGICAL SEC#.
;VARIES FROM $09-->$FF).
 BMI PRP4B2B6 ;WHEN (X) = #$FF, THEN WE HAVE
;READ ALL THE SECS IN, SO GO XIT.
 LDA PHYSECP8-$AE00,X ;EQUIVALENT 2 "LDA $84D,X".
;CONVERT LOGICAL SEC# 2 PHYS SEC#
 STA BOOTSEC ;STORE PHYSICAL SEC# IN PAGE0.
 DEC BT1PG2RD ;REDUCE PAGES (SECS) LEFT TO READ
;FOR NEXT TIME AROUND.
 LDA BT1LDADR+1 ;POINT BUFFER POINTER AT TARGET
 STA PT2BTBUF+1  ;ADR.  (VARIES FROM $BF TO $B6
;ON 48K SLAVE).
 DEC BT1LDADR+1 ;REDUCE HI BYTE OF I/O BUF FOR
;NEXT TIME AROUND.  (VARIES FROM
;$BF TO $B5 ON 48K SLAVE.)
 LDX SLT16ZPG ;SET (X) = SLOT*16.
 JMP (PTR2RDSC) ;EQUIVALENT TO "JMP ($8FD)" OR
;"JMP $CS5C" TO GO READ IN THE
;NEXT SECTOR.
;************ NOTE **************
;* GOES TO BT1EXC08 ($801) AFTER*
;* EACH SECTOR IS READ IN.      *
;* (REMEMBER, BT1EXCB6 IS A     *
;* CARBON COPY OF BT1EXC08.)    *
;********************************



	
PREPARE FOR BOOT2.



PRP4B2B6 INC BT1LDADR+1 ;IMAGE OF PR4B208 ($839).
;POINT AT THE LOAD ADR FOR BOOT2.
 INC BT1LDADR+1 ;(AFTR INCS, = $B7 ON 48K SLAVE).


	
SET FULL SCREEN TEXT & DESIGNATE

	
KEYBOARD & SCREEN AS I/O DEVICES.



 JSR SETKBD ;SIMULATE IN#0 (SET KSW: KEYIN).
 JSR SETVID ;SIMULATE PR#0 (SET CSW: COUT1).
 JSR INIT ;SIMULATE A "TEXT" STATEMENT.
  LDX SLT16ZPG ;(X) = SLOT*16.


	
------ GO TO BOOT2 ------ *



 JMP (BT1LDADR) ;JMP 2 BOOT2 ($B700 ON 48K SLAVE)



	
=================================

	
TABLE OF PHYSICAL SECTOR #'S.

	
($B64D - $B65C)

	
- AN IMAGE OF THIS TABLE IS

	
HOUSED AT $84D DURING THE BOOT.

	
=================================



;CORRESPONDING LOGICAL SECTOR #
PHYSECP8 HEX 00 ;             $00
 HEX 0D ;             $01
 HEX 0B ;             $02
 HEX 09 ;             $03
 HEX 07 ;             $04
 HEX 05 ;             $05
 HEX 03 ;             $06
 HEX 01 ;             $07
 HEX 0E ;             $08
 HEX 0C ;             $09
 HEX 0A ;             $0A
 HEX 08 ;             $0B
 HEX 06 ;             $0C
 HEX 04 ;             $0D
 HEX 02 ;             $0E
 HEX 0F ;             $0F
E