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Commodore 1571 firmware
File Lookup

        .page 
	.subttl 'lookup.src'
;  optsch  optimal search for lookup
;  and fndfil
	
optsch  lda  #0         ; determine optimal search
        sta  temp       ; init drive mask
        sta  drvflg      
        pha      
        ldx  f2cnt       
os10    pla      
        ora  temp        
        pha      
        lda  #1          
        sta  temp        
        dex      
        bmi  os30        
        lda  fildrv,x    
        bpl  os15        
        asl  temp        
        asl  temp        

os15    lsr  a   
        bcc  os10        
        asl  temp        
        bne  os10       ; (branch)

os30    pla      
        tax      
        lda  schtbl-1,x          
        pha      
        and  #3          
        sta  drvcnt      
        pla      
        asl  a   
        bpl  os40        
        lda  fildrv      
os35    and  #1          
        sta  drvnum      

        lda  drvcnt      
        beq  os60       ; only one drive addressed

        jsr  autoi      ; check drive for autoinit
        beq  os50       ; drive is active

        jsr  togdrv      
        lda  #0         ; set 1 drive addressed
        sta  drvcnt      
        jsr  autoi      ; check drive for autoinit
        beq  os70       ; drive is active
os45             
        lda  #nodriv     
        jsr  cmderr      
os50             
        jsr  togdrv      
        jsr  autoi      ; check drive for autoinit
        php      
        jsr  togdrv      
        plp      
        beq  os70       ; drive is active

        lda  #0         ; set 1 drive addressed
        sta  drvcnt      
        beq  os70       ; bra
os60             
        jsr  autoi      ; check drive for autoinit
        bne  os45       ; drive is not active
os70             
        jmp  setlds      

os40    rol  a   
        jmp  os35        

schtbl  .byte    0,$80,$41        
	.byte    1,1,1,1         
	.byte    $81,$81,$81,$81         
	.byte    $42,$42,$42,$42         
        .page  
;   look up all files in stream
;   and fill tables info

lookup  jsr  optsch      
lk05    lda  #0          
        sta  delind      
        jsr  srchst     ; start search
        bne  lk25        
lk10    dec  drvcnt      
        bpl  lk15        
        rts     	; no more drive searches

lk15    lda  #1         ; toggle drive #
        sta  drvflg      
        jsr  togdrv      
        jsr  setlds     ;  turn on led
        jmp  lk05        
lk20    jsr  search     ; find valid fn
        beq  lk30       ; end of search
lk25    jsr  compar     ; compare dir table
        lda  found      ; found flag
        beq  lk26       ; all fn's not found, yet
        rts      
	
lk26    lda  entfnd      
        bmi  lk20        
        bpl  lk25        

lk30    lda  found       
        beq  lk10        
        rts      

;  find next file name matching
;  any file in stream & return
;  with entry found stuffed into
;  tables

ffre    jsr  srre       ; find file re-entry
        beq  ff10        
        bne  ff25        

ff15    lda  #1          
        sta  drvflg      
        jsr  togdrv      
        jsr  setlds      

ffst    lda  #0         ; find file start entry
        sta  delind      
        jsr  srchst      
        bne  ff25        
        sta  found       
ff10    lda  found       
        bne  ff40        
        dec  drvcnt      
        bpl  ff15        
        rts      

fndfil  jsr  search     ; find file continuous...
        beq  ff10       ; ... re-entry, no channel activity
ff25    jsr  compar     ; compare file names
        ldx  entfnd      
        bpl  ff30        
        lda  found       
        beq  fndfil      
        bne  ff40        
	
ff30    lda  typflg      
        beq  ff40       ; no type restriction
        lda  pattyp,x    
        and  #typmsk     
        cmp  typflg      
        bne  fndfil      
ff40    rts      
        .page  

;  compare all filenames in stream table
;  with each valid entry in the 
;  directory.  matches are tabulated

compar  ldx  #$ff        
        stx  entfnd      
        inx      
        stx  patflg      
        jsr  cmpchk      
        beq  cp10        
cp02    rts     	; all are found

cp05    jsr  cc10        
        bne  cp02        
cp10    lda  drvnum      
        eor  fildrv,x    
        lsr  a   
        bcc  cp20       ; right drive
        and  #$40        
        beq  cp05       ; no default
        lda  #2          
        cmp  drvcnt      
        beq  cp05       ; don't use default

cp20    lda  filtbl,x   ; good drive match
        tax      
        jsr  fndlmt      
        ldy  #3          
        jmp  cp33        
cp30             
        lda  cmdbuf,x    
        cmp  (dirbuf),y          
        beq  cp32       ; chars are =

        cmp  #'?         
        bne  cp05       ; no single pattern
        lda  (dirbuf),y          
        cmp  #$a0        
        beq  cp05       ; end of filename
cp32             
        inx      
        iny      
cp33             
        cpx  limit       
        bcs  cp34       ; end of pattern

        lda  cmdbuf,x    
        cmp  #'*         
        beq  cp40       ; star matches all
        bne  cp30       ; keep checking
cp34             
        cpy  #19         
        bcs  cp40       ; end of filename

        lda  (dirbuf),y          
        cmp  #$a0        
        bne  cp05        

cp40    ldx  f2ptr      ; filenames match
        stx  entfnd      
        lda  pattyp,x   ; store info in tables
        and  #$80        
        sta  patflg      
        lda  index       
        sta  entind,x    
        lda  sector      
        sta  entsec,x    
        ldy  #0          
        lda  (dirbuf),y          
        iny      
        pha      
        and  #$40        
        sta  temp        
        pla      
        and  #$ff-$20    
        bmi  cp42        

        ora  #$20        
cp42             
        and  #$27        
        ora  temp        
        sta  temp        
        lda  #$80        
        and  pattyp,x    
        ora  temp        
        sta  pattyp,x    
        lda  fildrv,x    
        and  #$80        
        ora  drvnum      
        sta  fildrv,x    

        lda  (dirbuf),y          
        sta  filtrk,x    
        iny      
        lda  (dirbuf),y          
        sta  filsec,x    
        lda  rec         
        bne  cp50        
        ldy  #21         
        lda  (dirbuf),y          
        sta  rec         

;check table for unfound files

cp50             
cmpchk  lda  #$ff        
        sta  found       
        lda  f2cnt       
        sta  f2ptr       

cc10    dec  f2ptr       
        bpl  cc15        
        rts     	; table exhausted

cc15    ldx  f2ptr       
        lda  pattyp,x    
        bmi  cc20        
        lda  filtrk,x    
        bne  cc10        
cc20    lda  #0          
        sta  found       
        rts      
        .page  

;  search directory 
;  returns with valid entry delind=0
;  or returns 1st deleted entry
;  delind=1 
;
;  srchst will initiate a search
;  search will continue a search

srchst           
        ldy  #0         ; init deleted sector
        sty  delsec      
        dey      
        sty  entfnd      

        lda  dirtrk     ; start search at beginning
        sta  track       
        lda  #1          
        sta  sector      
        sta  lstbuf      
        jsr  opnird     ; open internal read chnl
	
sr10    lda  lstbuf     ; last buffer if 0
        bne  sr15        
        rts     	; (z=1)

sr15    lda  #7          
        sta  filcnt      
        lda  #0         ; read track #
        jsr  drdbyt      
        sta  lstbuf     ; update end flag

sr20    jsr  getpnt      
        dec  filcnt      
        ldy  #0          
        lda  (dirbuf),y ; read file type
        bne  sr30        

        lda  delsec     ; deleted entry found
        bne  search     ; deleted entry already found
        jsr  curblk     ; get current sector
        lda  sector      
        sta  delsec      

        lda  dirbuf     ; get current index
        ldx  delind     ; bit1: want deleted entry
        sta  delind      
        beq  search     ; need valid entry
        rts     	; (z=0)

sr30    ldx  #1          
        cpx  delind     ; ?looking for deleted?
        bne  sr50       ;  no!
        beq  search      

srre    lda  dirtrk      
        sta  track       
        lda  dirsec      
        sta  sector      
        jsr  opnird      
        lda  index       
        jsr  setpnt      

search  lda  #$ff        
        sta  entfnd      
        lda  filcnt     ; adjust file count
        bmi  sr40        
        lda  #32        ; incr by 32
        jsr  incptr      
        jmp  sr20        

sr40    jsr  nxtbuf     ; new buffer
        jmp  sr10       ; (branch)

sr50    lda  dirbuf     ; found valid entry
        sta  index      ; save index
        jsr  curblk     ; get sector
        lda  sector      
        sta  dirsec      

        rts     	; (z=0)
autoi            
;  check drive for active diskette
;  init if needed
;  return nodrv status

        lda  autofg      
        bne  auto2      ; auto-init is disabled

        ldx  drvnum      
        lsr  wpsw,x     ; test & clear wpsw
        bcc  auto2      ; no change in diskette

        lda  #$ff        
        sta  jobrtn     ; set error return code
        jsr  itrial     ; init-seek test
        ldy  #$ff       ;  .y= true
        cmp  #2          
        beq  auto1      ; no sync= no diskette

        cmp  #3          
        beq  auto1      ; no header= no directory

        cmp  #$f         
        beq  auto1      ; no drive!!!!

        ldy  #0         ; set .y false
auto1            
        ldx  drvnum      

;<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>

	jmp  ptch44	; *** rom ds 85 ***
;       tya      
;       sta  nodrv,x    ; set condn of no-drive
rtch44			; ret address

;<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>

        bne  auto2      ; no need to init crud!

        jsr  initdr     ; init that drive
auto2            
        ldx  drvnum      

;<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>

	jmp  ptch50	; *** rom ds 85 ***
;       lda  nodrv,x    ; return no-drive condn
;       rts      

;<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>


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This page has been created by Sami Rautiainen.
Read the small print. Last updated March 24, 1998.