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Text File | 1990-02-12 | 19.5 KB | 781 lines

.%083! ╫AIT FOR A BURST BYTE TO ARRIVE IN THE SERIAL DATA REGISTER OF ├╔┴#1 FROM THE FAST SERIAL BUS. .%084! SERIAL╫AIT = * .%085! LDA #$08 .%086! - BIT CIA╞LAGS .%087! BEQ - .%088! RTS .%089! ╫AIT FOR AND GET A BURST BYTE FROM THE FAST SERIAL BUS, AND SEND THE "─ATA ┴CCEPTED" SIGNAL. .%090! GET┬URST┬YTE = * .%091! JSR SERIAL╫AIT .%092! LDX CIA─ATA .%093! JSR TOGGLE├LOCK .%094! TXA .%095! RTS .%096! ╙END THE BURST COMMANDS TO "LOG IN" THE ═╙-─╧╙ DISK AND SET THE ╥EAD SECTOR INTERLEAVE FACTOR. .%097! MOUNT─ISK = * ;() : .├╙=ERR .%098! LDA #%00011010 .%099! JSR SEND╒0 .%100! BCC + .%101! RTS .%102! + JSR KERNEL╒NLSN .%103! BIT ST .%104! BMI SEND╒0┼RROR .%105! CLC .%106! JSR KERNEL╙PINP .%107! BIT CIA╞LAGS .%108! JSR TOGGLE├LOCK .%109! JSR GET┬URST┬YTE .%110! STA ERRNO .%111! AND #$0F .%112! CMP #2 .%113! BCS MOUNT┼XIT ╟RAB THE THROW-AWAY PARAMETERS FROM THE MOUNT OPERATION. .%114! LDY #0 .%115! - JSR GET┬URST┬YTE .%116! STA FORMAT╨ARMS,Y .%117! INY .%118! CPY #6 .%119! BCC - .%120! CLC ╙ET THE SECTOR INTERLEAVE TO 1 FOR A 1581 OR 4 FOR A 1571. .%121! ;** SET INTERLEAVE .%122! LDA #%00001000 .%123! JSR SEND╒0 .%124! BCC + .%125! RTS .%126! + LDA #1 ;INTERLEAVE OF 1 FOR 1581 .%127! BIT SOURCE╘YPE .%128! BMI + .%129! LDA #4 ;INTERLEAVE OF 4 FOR 1571 .%130! + JSR KERNEL├IOUT .%131! JSR KERNEL╒NLSN .%132! MOUNT┼XIT = * .%133! RTS .%134! ╥EAD ALL OF THE SECTORS OF A GIVEN TRACK INTO THE TRACK CACHE. .%135! BUFPTR = 2 .%136! SECNUM = 4 .%137! .%138! READ╘RACK = * ;( .┴=CYLINDER, .╪=SIDE ) : TRACKBUF, .├╙=ERR .%139! PHA .%140! TXA ╟ET THE SIDE AND PUT IT INTO THE COMMAND BYTE. ╥EMEMBER THAT WE HAVE TO FLIP THE SIDE BIT FOR A 1581. .%141! AND #$01 .%142! ASL .%143! ASL .%144! ASL .%145! ASL .%146! BIT SOURCE╘YPE .%147! BPL + .%148! EOR #$10 .%149! + JSR SEND╒0 .%150! BCC + .%151! RTS .%152! + PLA ;CYLINDER NUMBER .%153! JSR KERNEL├IOUT .%154! LDA #1 ;START SECTOR NUMBER .%155! JSR KERNEL├IOUT .%156! LDA #9 ;SECTOR COUNT .%157! JSR KERNEL├IOUT .%158! JSR KERNEL╒NLSN ╨REPARE TO RECEIVE THE TRACK DATA. .%159! SEI .%160! CLC .%161! JSR KERNEL╙PINP .%162! BIT CIA╞LAGS .%163! JSR TOGGLE├LOCK .%164! LDA #<TRACKBUF .%165! LDY #>TRACKBUF .%166! STA BUFPTR .%167! STY BUFPTR+1 ╟ET THE SECTOR DATA FOR EACH OF THE 9 SECTORS OF THE TRACK. .%168! LDA #0 .%169! STA SECNUM .%170! - BIT SOURCE╘YPE .%171! BMI + ╔F WE ARE DEALING WITH A 1571, WE HAVE TO SET THE BUFFER POINTER FOR THE NEXT SECTOR, TAKING INTO ACCOUNT THE SOFT INTERLEAVE OF 4. .%172! JSR GET1571┬UF╨TR .%173! + JSR READ╙ECTOR .%174! BCS TRACK┼XIT .%175! INC SECNUM .%176! LDA SECNUM .%177! CMP #9 .%178! BCC - .%179! CLC .%180! TRACK┼XIT = * .%181! CLI .%182! RTS .%183! ╟ET THE BUFFER POINTER FOR THE NEXT 1571 SECTOR. .%184! GET1571┬UF╨TR = * .%185! LDA #<TRACKBUF .%186! STA BUFPTR .%187! LDX SECNUM .%188! CLC .%189! LDA #>TRACKBUF .%190! ADC BUFPTR1571,X .%191! STA BUFPTR+1 .%192! RTS .%193! .%194! BUFPTR1571 = * .%195! .BYTE 0,8,16,6,14,4,12,2,10 .%196! ╥EAD AN INDIVIDUAL SECTOR INTO MEMORY AT THE SPECIFIED ADDRESS. .%197! READ╙ECTOR = * ;( BUFPTR ) : .├╙=ERR ╟ET AND CHECK THE BURST STATUS BYTE FOR ERRORS. .%198! JSR GET┬URST┬YTE .%199! STA ERRNO .%200! AND #$0F .%201! CMP #2 .%202! BCC + .%203! RTS .%204! + LDX #2 .%205! LDY #0 .%206! ╥ECEIVE THE 512 SECTOR DATA BYTES INTO MEMORY. .%207! READ┬YTE = * .%208! LDA #$08 .%209! - BIT CIA╞LAGS .%210! BEQ - .%211! LDA CIA├LOCK .%212! EOR #$10 .%213! STA CIA├LOCK .%214! LDA CIA─ATA .%215! STA (BUFPTR),Y .%216! INY .%217! BNE READ┬YTE .%218! INC BUFPTR+1 .%219! DEX .%220! BNE READ┬YTE .%221! RTS .%222! ╘HIS NEXT LEVEL OF ROUTINES DEALS WITH LOGICAL SECTORS AND THE TRACK CACHE RATHER THAN WITH HARDWARE. .%223! ;====LOGICAL SECTOR LEVEL==== .%224! ╔NVALIDATE THE TRACK CACHE IF THE ═╙-─╧╙ DRIVE NUMBER IS CHANGED OR IF A NEW DISK IS INSERTED. ╘HIS ROUTINE HAS TO ESTABLISH A ╥┴═ CONFIGURATION OF $0┼ SINCE IT WILL BE CALLED FROM ╥┴═0. ├ONFIGURATION $0┼ GIVES ╥┴═0 FROM $0000 TO $┬╞╞╞, ╦ERNAL ╥╧═ FROM $├000 TO $╞╞╞╞, AND THE ╔/╧ SPACE OVER THE ╦ERNAL FROM $─000 TO $─╞╞╞. ╘HIS CONFIGURATION IS SET BY ALL APPLICATION INTERFACE SUBROUTINES. .%225! INIT╨ACKAGE = * .%226! LDA #$0E .%227! STA $FF00 .%228! LDA #$FF .%229! STA BUF├YLINDER .%230! STA BUF╙IDE .%231! CLC .%232! RTS .%233! ╠OCATE A SECTOR (BLOCK) IN THE TRACK CACHE, OR READ THE CORRESPONDING PHYSICAL TRACK INTO THE TRACK CACHE IF NECESSARY. ╘HIS ROUTINE ACCEPTS THE CYLINDER, SIDE, AND SECTOR NUMBERS OF THE BLOCK. .%234! SECTOR╙AVE = 5 .%235! .%236! READ┬LOCK = * ;( .┴=CYLINDER,.╪=SIDE,.┘=SECTOR ) : .┴┘=BLK╨TR,.├╙=ERR ├HECK IF THE CORRECT TRACK IS IN THE TRACK CACHE. .%237! CMP BUF├YLINDER .%238! BNE READ┬LOCK╨HYSICAL .%239! CPX BUF╙IDE .%240! BNE READ┬LOCK╨HYSICAL ╔F SO, THEN LOCATE THE SECTOR'S ADDRESS AND RETURN THAT. .%241! DEY .%242! TYA .%243! ASL .%244! CLC .%245! ADC #>TRACKBUF .%246! TAY .%247! LDA #<TRACKBUF .%248! CLC .%249! RTS .%250! ╚ERE, WE HAVE TO READ THE PHYSICAL TRACK INTO THE TRACK CACHE. ╫E SAVE THE INPUT PARAMETERS AND CALL THE HARDWARE-LEVEL TRACK-READING ROUTINE. .%251! READ┬LOCK╨HYSICAL = * .%252! STA BUF├YLINDER .%253! STX BUF╙IDE .%254! STY SECTOR╙AVE .%255! JSR READ╘RACK ├HECK FOR ERRORS. .%256! BCC READ┬LOCK╨HYSICAL╧K .%257! LDA ERRNO .%258! AND #$0F .%259! CMP #11 ;DISK CHANGE .%260! BEQ + .%261! SEC .%262! RTS ╔F THE ERROR THAT HAPPENED IS A "─ISK ├HANGE" ERROR, THEN MOUNT THE DISK AND TRY TO READ THE PHYSICAL TRACK AGAIN. .%263! + JSR MOUNT─ISK .%264! LDA BUF├YLINDER .%265! LDX BUF╙IDE .%266! LDY SECTOR╙AVE .%267! BCC READ┬LOCK╨HYSICAL .%268! RTS .%269! ╚ERE, THE PHYSICAL TRACK HAS BEEN READ INTO THE TRACK CACHE OK, SO WE RECOVER THE ORIGINAL INPUT PARAMETERS AND TRY THE TOP OF THE ROUTINE AGAIN. .%270! READ┬LOCK╨HYSICAL╧K = * .%271! LDA BUF├YLINDER .%272! LDX BUF╙IDE .%273! LDY SECTOR╙AVE .%274! JMP READ┬LOCK .%275! ─IVIDE THE GIVEN NUMBER BY 18. ╘HIS IS NEEDED FOR THE CALCULATIONS TO CONVERT A LOGICAL SECTOR NUMBER TO THE CORRESPONDING PHYSICAL CYLINDER, SIDE, AND SECTOR NUMBERS THAT THE LOWER-LEVEL ROUTINES REQUIRE. ╘HE METHOD OF REPEATED SUBTRACTION IS USED. ╘HIS ROUTINE WOULD PROBABLY WORK FASTER IF WE TRIED TO REPEATEDLY SUBTRACT 360 (18*20) AT THE TOP, BUT ╔ DIDN'T BOTHER. .%276! DIVIDE┬Y18 = * ;( .┴┘=NUMBER ) : .┴=QUOTIENT, .┘=REMAINDER .%277! ;** COULD REPEATEDLY SUBTRACT 360 HERE .%278! LDX #$FF .%279! - INX .%280! SEC .%281! SBC #18 .%282! BCS - .%283! DEY .%284! BPL - .%285! CLC .%286! ADC #18 .%287! INY .%288! TAY .%289! TXA .%290! RTS .%291! ├ONVERT THE GIVEN LOGICAL BLOCK NUMBER TO THE CORRESPONDING PHYSICAL CYLINDER, SIDE, AND SECTOR NUMBERS. ╘HIS ROUTINE FOLLOWS THE FORMULAE GIVEN EARLIER WITH A FEW SIMPLIFYING TRICKS. .%292! CONVERT╠OGICAL┬LOCK╬UM = * ;( .┴┘=BLOCK╬UM ) : .┴=CYL, .╪=SIDE, .┘=SEC .%293! JSR DIVIDE┬Y18 .%294! LDX #0 .%295! CPY #9 .%296! BCC + .%297! PHA .%298! TYA .%299! SBC #9 .%300! TAY .%301! PLA .%302! LDX #1 .%303! + INY .%304! RTS .%305! ├OPY A SEQUENTIAL GROUP OF LOGICAL SECTORS INTO MEMORY. ╘HIS ROUTINE IS USED BY THE DIRECTORY LOADING ROUTINE TO LOAD THE ╞┴╘ AND ╥OOT ─IRECTORY, AND IS USED BY THE CLUSTER READING ROUTINE TO RETRIEVE ALL OF THE BLOCKS OF A CLUSTER. ┴FTER THE GIVEN STARTING LOGICAL SECTOR NUMBER IS CONVERTED INTO ITS PHYSICAL CYLINDER, SIDE, AND SECTOR EQUIVALENT, THE PHYSICAL VALUES ARE INCREMENTED TO GET THE ADDRESS OF SUCCESSIVE SECTORS OF THE GROUP. ╘HIS AVOIDS THE OVERHEAD OF THE LOGICAL TO PHYSICAL CONVERSION. ╤UITE A NUMBER OF TEMPORARIES ARE NEEDED. .%306! DEST╨TR = 6 .%307! CUR├YLINDER = 8 .%308! CUR╙IDE = 9 .%309! CUR╙ECTOR = 10 .%310! BLOCK├OUNTDOWN = 11 .%311! SOURCE╨TR = 12 .%312! .%313! COPY┬LOCKS = * ;( .┴┘=START┬LOCK, .╪=BLOCK├OUNT, ($6)=DEST ) : .├╙=ERR .%314! STX BLOCK├OUNTDOWN .%315! JSR CONVERT╠OGICAL┬LOCK╬UM .%316! STA CUR├YLINDER .%317! STX CUR╙IDE .%318! STY CUR╙ECTOR .%319! .%320! COPY┬LOCK╠OOP = * .%321! LDA CUR├YLINDER .%322! LDX CUR╙IDE .%323! LDY CUR╙ECTOR .%324! JSR READ┬LOCK .%325! BCC + .%326! RTS .%327! + STA SOURCE╨TR .%328! STY SOURCE╨TR+1 .%329! LDX #2 .%330! LDY #0 ╚ERE ╔ UNROLL THE COPYING LOOP A LITTLE BIT TO CUT THE OVERHEAD OF THE BRANCH INSTRUCTION IN HALF. (┴ CYCLE SAVED... YOU KNOW). .%331! - LDA (SOURCE╨TR),Y .%332! STA (DEST╨TR),Y .%333! INY .%334! LDA (SOURCE╨TR),Y .%335! STA (DEST╨TR),Y .%336! INY .%337! BNE - .%338! INC SOURCE╨TR+1 .%339! INC DEST╨TR+1 .%340! DEX .%341! BNE - ╔NCREMENT THE CYLINDER, SIDE, SECTOR VALUES. .%342! INC CUR╙ECTOR .%343! LDA CUR╙ECTOR .%344! CMP #10 .%345! BCC + .%346! LDA #1 .%347! STA CUR╙ECTOR .%348! INC CUR╙IDE .%349! LDA CUR╙IDE .%350! CMP #2 .%351! BCC + .%352! LDA #0 .%353! STA CUR╙IDE .%354! INC CUR├YLINDER .%355! + DEC BLOCK├OUNTDOWN .%356! BNE COPY┬LOCK╠OOP .%357! CLC .%358! RTS .%359! ╥EAD A CLUSTER INTO THE ├LUSTER ┬UFFER, GIVEN THE CLUSTER NUMBER. ╘HE CLUSTER NUMBER IS CONVERTED TO A LOGICAL SECTOR NUMBER AND THEN THE SECTOR COPYING ROUTINE IS CALLED. ╘HE FORMULA GIVEN EARLIER IS USED FOR THE CONVERSION. .%360! READ├LUSTER = * ;( .┴┘=CLUSTER╬UMBER ) : CLUSTER┬UF, .├╙=ERR .%361! ;** CONVERT CLUSTER NUMBER TO LOGICAL BLOCK NUMBER .%362! SEC .%363! SBC #2 .%364! BCS + .%365! DEY .%366! + LDX CLUSTER┬LOCK├OUNT .%367! CPX #1 .%368! BEQ + .%369! ASL .%370! STY 7 .%371! ROL 7 .%372! LDY 7 .%373! + CLC .%374! ADC FIRST╞ILE┬LOCK .%375! BCC + .%376! INY .%377! .%378! ;** READ LOGICAL BLOCKS COMPRISING CLUSTER .%379! + LDX #<CLUSTER┬UF .%380! STX 6 .%381! LDX #>CLUSTER┬UF .%382! STX 7 .%383! LDX CLUSTER┬LOCK├OUNT .%384! JMP COPY┬LOCKS .%385! ╘HIS NEXT LEVEL OF ROUTINES DEAL WITH THE DATA STRUCTURES OF THE ═╙-─╧╙ DISK FORMAT. .%386! ;====═╙-─╧╙ FORMAT LEVEL==== .%387! .%388! BOOT┬LOCK = 2 .%389! ╥EAD THE DISK FORMAT PARAMETERS, DIRECTORY, AND ╞┴╘ INTO MEMORY. .%390! LOAD─IRECTORY = * ;( ) : .┴┘=DIRBUF, .╪=DIR┼NTRIES, .├╙=ERR .%391! LDA #$0E .%392! STA $FF00 .%393! ╥EAD THE BOOT SECTOR AND EXTRACT THE PARAMETERS. .%394! ;** GET PARAMETERS FROM BOOT SECTOR .%395! LDA #0 .%396! LDY #0 .%397! JSR CONVERT╠OGICAL┬LOCK╬UM .%398! JSR READ┬LOCK .%399! BCC + .%400! RTS .%401! + STA BOOT┬LOCK .%402! STY BOOT┬LOCK+1 .%403! LDY #13 ;GET CLUSTER SIZE .%404! LDA (BOOT┬LOCK),Y .%405! STA CLUSTER┬LOCK├OUNT .%406! CMP #3 .%407! BCC + .%408! ╔F A DISK PARAMETER IS FOUND TO EXCEED THE LIMITS OF ╠╥╥, ERROR CODE #60 IS RETURNED. .%409! INVALID╨ARMS = * .%410! LDA #60 .%411! STA ERRNO .%412! SEC .%413! RTS .%414! .%415! + LDY #16 ;CHECK ╞┴╘ REPLICATION COUNT, MUST BE 2 .%416! LDA (BOOT┬LOCK),Y .%417! CMP #2 .%418! BNE INVALID╨ARMS .%419! LDY #22 ;GET ╞┴╘ SIZE IN SECTORS .%420! LDA (BOOT┬LOCK),Y .%421! STA FAT┬LOCKS .%422! CMP #4 .%423! BCS INVALID╨ARMS .%424! LDY #17 ;GET DIRECTORY SIZE .%425! LDA (BOOT┬LOCK),Y .%426! STA ROOT─IR┼NTRIES .%427! CMP #129 .%428! BCS INVALID╨ARMS .%429! LSR .%430! LSR .%431! LSR .%432! LSR .%433! STA ROOT─IR┬LOCKS .%434! LDY #19 ;GET TOTAL SECTOR COUNT .%435! LDA (BOOT┬LOCK),Y .%436! STA TOTAL╙ECTORS .%437! INY .%438! LDA (BOOT┬LOCK),Y .%439! STA TOTAL╙ECTORS+1 .%440! LDY #24 ;CHECK SECTORS PER TRACK, MUST BE 9 .%441! LDA (BOOT┬LOCK),Y .%442! CMP #9 .%443! BNE INVALID╨ARMS .%444! LDY #26 .%445! LDA (BOOT┬LOCK),Y .%446! CMP #2 ;CHECK NUMBER OF SIDES, MUST BE 2 .%447! BNE INVALID╨ARMS .%448! LDY #14 ;CHECK NUMBER OF BOOT SECTORS, MUST BE 1 .%449! LDA (BOOT┬LOCK),Y .%450! CMP #1 .%451! BNE INVALID╨ARMS .%452! ├ALCULATE THE DERIVED PARAMETERS. .%453! ;** GET DERIVED PARAMETERS .%454! LDA FAT┬LOCKS ;FIRST ROOT DIRECTORY SECTOR .%455! ASL .%456! CLC .%457! ADC #1 .%458! STA FIRST╥OOT─IR┬LOCK .%459! CLC ;FIRST FILE SECTOR .%460! ADC ROOT─IR┬LOCKS .%461! STA FIRST╞ILE┬LOCK .%462! LDA TOTAL╙ECTORS ;NUMBER OF FILE CLUSTERS .%463! LDY TOTAL╙ECTORS+1 .%464! SEC .%465! SBC FIRST╞ILE┬LOCK .%466! BCS + .%467! DEY .%468! + STA FILE├LUSTER├OUNT .%469! STY FILE├LUSTER├OUNT+1 .%470! LDA CLUSTER┬LOCK├OUNT .%471! CMP #2 .%472! BNE + .%473! LSR FILE├LUSTER├OUNT+1 .%474! ROR FILE├LUSTER├OUNT .%475! ╟EE, ╔ HAVE MORE COMMENTS EMBEDDED IN THE CODE THAN ╔ DID LAST ISSUE. .%476! ;** LOAD ╞┴╘ .%477! + LDA #<FATBUF .%478! LDY #>FATBUF .%479! STA 6 .%480! STY 7 .%481! LDA #1 .%482! LDY #0 .%483! LDX FAT┬LOCKS .%484! JSR COPY┬LOCKS .%485! BCC + .%486! RTS .%487! .%488! ;** LOAD ACTUAL DIRECTORY .%489! + LDA #<DIRBUF .%490! LDY #>DIRBUF .%491! STA 6 .%492! STY 7 .%493! LDA FIRST╥OOT─IR┬LOCK .%494! LDY #0 .%495! LDX ROOT─IR┬LOCKS .%496! JSR COPY┬LOCKS .%497! BCC + .%498! RTS .%499! + LDA #<DIRBUF .%500! LDY #>DIRBUF .%501! LDX ROOT─IR┼NTRIES .%502! CLC .%503! RTS .%504! ╘HIS ROUTINE LOCATES THE GIVEN ╞┴╘ TABLE ENTRY NUMBER AND RETURNS THE VALUE STORED IN IT. ╙OME WORK IS NEEDED TO DEAL WITH THE 12-BIT COMPRESSED DATA STRUCTURE. .%505! ENTRY┴DDR = 2 .%506! ENTRY╫ORK = 4 .%507! ENTRY┬ITS = 5 .%508! ENTRY─ATA0 = 6 .%509! ENTRY─ATA1 = 7 .%510! ENTRY─ATA2 = 8 .%511! .%512! GET╞AT┼NTRY = * ;( .┴┘=FAT┼NTRY╬UMBER ) : .┴┘=FAT┼NTRY╓ALUE .%513! STA ENTRY┬ITS ─IVIDE THE ╞┴╘ ENTRY NUMBER BY TWO AND MULTIPLY BY THREE BECAUSE TWO ╞┴╘ ENTRIES ARE STORED IN THREE BYTES. ╘HEN ADD THE ╞┴╘ BASE ADDRESS AND WE HAVE THE ADDRESS OF THE THREE BYTES THAT CONTAIN THE ╞┴╘ ENTRY WE ARE INTERESTED IN. ╔ RETRIEVE THE THREE BYTES INTO ZERO-PAGE MEMORY FOR EASY MANIPULATION. .%514! ;** DIVIDE BY TWO .%515! STY ENTRY┴DDR+1 .%516! LSR ENTRY┴DDR+1 .%517! ROR .%518! .%519! ;** TIMES THREE .%520! STA ENTRY╫ORK .%521! LDX ENTRY┴DDR+1 .%522! ASL .%523! ROL ENTRY┴DDR+1 .%524! CLC .%525! ADC ENTRY╫ORK .%526! STA ENTRY┴DDR .%527! TXA .%528! ADC ENTRY┴DDR+1 .%529! STA ENTRY┴DDR+1 .%530! .%531! ;** ADD BASE, GET DATA .%532! CLC .%533! LDA ENTRY┴DDR .%534! ADC #<FATBUF .%535! STA ENTRY┴DDR .%536! LDA ENTRY┴DDR+1 .%537! ADC #>FATBUF .%538! STA ENTRY┴DDR+1 .%539! LDY #2 .%540! - LDA (ENTRY┴DDR),Y .%541! STA ENTRY─ATA0,Y .%542! DEY .%543! BPL - .%544! LDA ENTRY┬ITS .%545! AND #1 .%546! BNE + .%547! ╔F THE ORIGINAL GIVEN ╞┴╘ ENTRY NUMBER IS EVEN, THEN WE WANT THE FIRST 12-BIT COMPRESSED FIELD. ╘HE NYBBLES ARE EXTRACTED ACCORDING TO THE DIAGRAM SHOWN EARLIER. .%548! ;** CASE 1: FIRST 12-BIT CLUSTER .%549! LDA ENTRY─ATA1 .%550! AND #$0F .%551! TAY .%552! LDA ENTRY─ATA0 .%553! RTS .%554! ╧THERWISE, WE WANT THE SECOND 12-BIT FIELD. .%555! ;** CASE 2: SECOND 12-BIT CLUSTER .%556! + LDA ENTRY─ATA1 .%557! LDX #4 .%558! - LSR ENTRY─ATA2 .%559! ROR .%560! DEX .%561! BNE - .%562! LDY ENTRY─ATA2 .%563! RTS .%564! ╞INALLY, THIS IS THE FILE COPYING LEVEL. ╔T DEALS WITH READING THE CLUSTERS OF ═╙-─╧╙ FILES AND COPYING THE DATA THEY CONTAIN TO THE ALREADY-OPEN ├┬═ ╦ERNAL FILE, POSSIBLY WITH ┴╙├╔╔-TO-╨┼╘╙├╔╔ TRANSLATION. .%565! ;====FILE COPY LEVEL==== .%566! .%567! TRANS═ODE = 14 .%568! LFN = 15 .%569! CBM─ATA╨TR = $60 .%570! CBM─ATA╠EN = $62 .%571! CLUSTER = $64 .%572! ├OPY THE GIVEN CLUSTER TO THE ├┬═ OUTPUT FILE. ╘HIS ROUTINE FETCHES THE NEXT CLUSTER OF THE FILE FOR THE NEXT TIME THIS ROUTINE IS CALLED, AND IF IT HITS THE ╬╒╠╠ POINTER OF THE LAST CLUSTER OF A FILE, IT ADJUSTS THE NUMBER OF VALID FILE DATA BYTES THE CURRENT CLUSTER CONTAINS TO ╞ILE╠ENGTH % ├LUSTER╠ENGTH (SEE NOTE BELOW). .%573! COPY╞ILE├LUSTER = * ;( CLUSTER, LFN, TRANS═ODE ) : .├╙=ERR ╥EAD THE CLUSTER AND SETUP TO COPY THE WHOLE CLUSTER TO THE ├┬═ FILE. .%574! LDA CLUSTER .%575! LDY CLUSTER+1 .%576! JSR READ├LUSTER .%577! BCC + .%578! RTS .%579! + LDA #<CLUSTER┬UF .%580! LDY #>CLUSTER┬UF .%581! STA CBM─ATA╨TR .%582! STY CBM─ATA╨TR+1 .%583! LDA #0 .%584! STA CBM─ATA╠EN .%585! LDA CLUSTER┬LOCK├OUNT .%586! ASL .%587! STA CBM─ATA╠EN+1 .%588! ╞ETCH THE NEXT CLUSTER NUMBER OF THE FILE, AND ADJUST THE CLUSTER DATA LENGTH FOR THE LAST CLUSTER OF THE FILE. .%589! ;**GET NEXT CLUSTER .%590! LDA CLUSTER .%591! LDY CLUSTER+1 .%592! JSR GET╞AT┼NTRY .%593! STA CLUSTER .%594! STY CLUSTER+1 .%595! CMP #$FF .%596! BNE COPY╞ILE├LUSTER─ATA .%597! CPY #$0F .%598! BNE COPY╞ILE├LUSTER─ATA .%599! LDA LEN═╠ .%600! STA CBM─ATA╠EN .%601! LDA #$01 .%602! LDX CLUSTER┬LOCK├OUNT .%603! CPX #1 .%604! BEQ + .%605! LDA #$03 .%606! + AND LEN═╠+1 ╘HE FOLLOWING THREE LINES WERE ADDED IN A LAST MINUTE PANIC AFTER REALIZING THAT IF ╞ILE╠ENGTH % ├LUSTER╙IZE == 0, THEN THE LAST CLUSTER OF THE FILE CONTAINS ├LUSTER╙IZE BYTES, NOT ZERO BYTES. .%000! BNE + .%000! LDX LEN═╠ .%000! BEQ COPY╞ILE├LUSTER─ATA .%607! + STA CBM─ATA╠EN+1 .%608! .%609! COPY╞ILE├LUSTER─ATA = * .%610! JSR COMMIE╧UT .%611! RTS .%612! ├OPY THE FILE DATA IN THE ═╙-─╧╙ CLUSTER BUFFER TO THE ├┬═ OUTPUT FILE. .%613! CBM─ATA╠IMIT = $66 .%614! .%615! COMMIE╧UT = * ;( CBM─ATA╨TR, CBM─ATA╠EN ) : .├╙=ERR ╔F THE THE LOGICAL FILE NUMBER TO COPY TO IS 0 ("NULL DEVICE"), THEN DON'T BOTHER COPYING ANYTHING. .%616! LDX LFN .%617! BNE + .%618! CLC .%619! RTS ╧THERWISE, PREPARE THE LOGICAL FILE NUMBER FOR OUTPUT. .%620! + JSR KERNEL├HKOUT .%621! BCC COMMIE╧UT═ORE .%622! STA ERRNO .%623! RTS .%624! .%625! COMMIE╧UT═ORE = * ╨ROCESS THE CLUSTER DATA IN CHUNKS OF UP TO 255 BYTES OR THE NUMBER OF DATA BYTES REMAINING IN THE CLUSTER. .%626! LDA #255 .%627! LDX CBM─ATA╠EN+1 .%628! BNE + .%629! LDA CBM─ATA╠EN .%630! + STA CBM─ATA╠IMIT .%631! LDY #0 .%632! - LDA (CBM─ATA╨TR),Y .%633! BIT TRANS═ODE .%634! BPL + ╔F WE HAVE TO TRANSLATE THE CURRENT ┴╙├╔╔ CHARACTER, LOOK UP THE ╨┼╘╙├╔╔ VALUE IN THE TRANSLATION TABLE AND OUTPUT THAT VALUE. ╔F THE TRANSLATION TABLE ENTRY VALUE IS $00, THEN DON'T OUTPUT A CHARACTER (FILTER OUT INVALID CHARACTER CODES). .%635! TAX .%636! LDA TRANS┬UF,X .%637! BEQ COMMIE╬EXT .%638! + JSR KERNEL├HROUT .%639! COMMIE╬EXT = * .%640! INY .%641! CPY CBM─ATA╠IMIT .%642! BNE - .%643! ╔NCREMENT THE CLUSTER BUFFER POINTER AND DECREMENT THE CLUSTER BUFFER CHARACTER COUNT ACCORDING TO THE NUMBER OF BYTES JUST PROCESSED, AND REPEAT THE ABOVE IF MORE FILE DATA REMAINS IN THE CURRENT CLUSTER. .%644! CLC .%645! LDA CBM─ATA╨TR .%646! ADC CBM─ATA╠IMIT .%647! STA CBM─ATA╨TR .%648! BCC + .%649! INC CBM─ATA╨TR+1 .%650! + SEC .%651! LDA CBM─ATA╠EN .%652! SBC CBM─ATA╠IMIT