fstutl.src

	.page  
	.subttl 'fstutl.src'

;  BURST COMMAND INSTRUCTION SET
;
;NOTE: PREFIX = Ascii "U0"
;           X = Don't Care.
;          
;         CMD 1    N = %TEBS000x       : Burst read cmd.
;
;                   PREFIX+N+TT+SS+NN+NT
;
;	switch:	       T ............ Transfer data = 0
;		       E ............ Ignore Error = 1 
;                      B ............ Buffer Transfer Only = 1
;		       S ............ Side Select (MFM Only).
;		       x ............ Drive number.
;
;	 input:        TT ............ Destination track.
;                      SS ............ Destination sector.
;                      NN ............ Number of sectors to be read.
;                      NT ... opt .... Next track address.
;
;          output: Status byte + Data (Burst).
;
;
;         
;	
;
;
;
;
;
;
;
;
;	CMD 2    N = %TEBS001x       : Burst write cmd.
;
;                   PREFIX+N+TT+SS+NN+NT
;
;	switch:	       T ............ Transfer data = 0
;		       E ............ Ignore Error = 1 
;                      B ............ Buffer Transfer Only = 1
;		       S ............ Side Select (MFM Only).
;		       x ............ Drive number.
;
;	 input:	       TT ............ Destination track number.
;                      SS ............ Destination sector.
;                      NN ............ Number of sectors to be
;                                      written.
;                      NT ... opt .... Next track address.
;                      Data (Burst).
;
;         output:     Status byte (burst).
;
;
;
;
;
;
;
;
;
;
;
;         CMD 3    N = %XXXS010x       : Inquire diskette type.
;
;                    PREFIX+N
;
;	 input:     x ............  Drive Number.
;	            S ............  Side Select (MFM Only).
;	
;	output: Status byte (burst).
;
;
;
;
;
;
;
;
;
;
;
;         CMD 4    N = %PIDS011x       : Format diskette
;
;                    PREFIX+N+MD+CP+SZ+LT+NS+ST+S+FL ( MFM )
;                    PREFIX+N+MD+ID1+ID2 (GCR)
;
;	switch:	       P ............ Partial Format = 0
;		       I ............ Index Mark written + Preamble, I = 1
;		       S ............ Side, 1=side 1 & 0 = side 0
;		       D ............ Double Sided Select, 1=double sided
;				      (MFM Only).
;
; 	 input:       MD ............ %MTLLLLLL
;		       M ............ Mode M=1(MFM), M=0(GCR)
;		  ***  T ............ Sector Table Download, T=1
;	         LLLLLLL ............ Logical Sector Number.
;
;                      x ............ Drive Number.
;
;           ** MFM (a-f)
;		    a) CP ... opt .... CP/M Interleave (Def 6)
;                   b) SZ ... opt .... Sector size.
;                                 %00000000 = 128
;                                 %00000001 = 256 Default.
;                                 %00000010 = 512
;                                 %00000011 = 1024
;
;                   c) LT ... opt .... Last track number (Def 39).
;                   d) NS ... opt .... Number of sectors per track.
;                                    (Default depends on sector size)
;
;                   e) ST ... opt .... Starting track (Def 0) logical.
;                   f) S  ... opt .... Starting Offset (Def 0) physical.
;                   g) FL ... opt .... Fill Byte (Def $e5).
;
;              GCR
;                  a) ID1 ............ Identification byte low.
;                  b) ID2 ............ Identification byte high.
;          output: NONE.
;
;
;         ** With the P bit set the format will end at LT and 
;	     track LT+1 will be cleared (MFM only).
;
;	 *** With the T bit set a sector Table may be downloaded
;	     following a complete parameter list.
;	     i.e. PREFIX+N+MD+CP+SZ+LT+NS+ST+S+FL + SECTOR_TABLE
;	     This is necessary for example KAYPRO Disk Format.	
;
;
;
;
;
;
;         CMD 5    N = %WXX0100x       : Sector interleave CP/M.
;
;                    PREFIX+N+IT
;
;	switch:  T ............ Transfer data = 0
;
;	 input:  W ................ Write = 0
;                x ................ Drive Number.
;               IT ................ Interleave.
;
;         output: With the W bit cleared CP/M interleave is sent
;	         as a burst byte.
;
;
;
;
;
;
;
;
;
;         CMD 6    N = %FXS0101x       : Query disk format.
;
;                    PREFIX+N+STP
;
;
;          switch: F ................. Force Flag for STP below, F = 1
;		   S ................. Side Select (MFM Only).
;
;           input: x ................. Drive Number.
;	         STP .... opt ........ Physical steps from track zero.
;
;          output: * Status Byte 
;		  ** Status Byte on the below data bytes.
;		     Number of sectors.
;		     Logical Track.
;		     Minimum sector number.
;		     Maximum sector number.
;		     CP/M Interleave.
;	          		  
;*  If an error occurs or mode is GCR then no futher bytes will be sent.
;** If an error occurs then no futher bytes will be sent.
;
;
;
;
;
;
;
;
;
;
;
;         CMD 7    N = %WXX0110x       : Inquire Status.
;
;                    PREFIX+N+S
;
;          switch: T ................. Transfer data = 0
;
;           input: x ................. Drive Number.
;		   W ................. Write = 0
;		   S ................. With W bit set S is new status.
;
;          output: With the W bit cleared status is sent
;                  as a burst byte.
;
;
;
;
;
;
;
;
;
;
;
;
;         CMD 8    N = %XXX0111x       : Backup Disk (2-drive only)
;
;                    PREFIX+N+MD
;
;           input: To be determined.
;          output: To be determined.
;
;
;
;
;
;
;
;
;
;         CMD 9   N = %XXX11110       : Chgutl utility
;
;                    PREFIX+N+P+Q
;
;           input: P ................. Command Parameter
;
;		 'S'................. Dos Sector Interleave (GCR)
;				      Q=(0-255), def 6
;			              "U0>" + CHR$(INT)
;
;		 'R'................. DOS Retries
;				      Q=(1-127), def 5
;			              "U0>" + CHR$(RET)
;
;		 'T'................. Signature Analysis ROM.
;			              Failure 4 blinks from Activity
;				      LED.
;			              "U0>T"
;
;		 'M'................. Mode Change Utility.
;			              "U0>1" = 1571, "U0>0" = 1541
;
;            switch: No diskette init change ">" to hold commodore 
;					key and type the letter"V"
;
;
;
;		 'H'................. Head Change Utility.
;			              "U0>1" = Side 1, "U0>0" = Side 0
;
;            switch: No diskette init change ">" to hold commodore 
;					key and type the letter"V"
;
;
;
;
;	       Q=(8-15 Decimal)...... Device Number Change.	             
;			              "U0>" + CHR$(DEV)
;
;
;
;
;
;
;
;
;
;
;
;         CMD 10   N = %PXX11111       : Burst load utility
;
;                    PREFIX+N+FILENAME
;
;          switch: P ............ If this bit is set than the file type
;				  may be a sequential file.
;
;           input: FILENAME ................. ASCII FILE NAME
;         
;          output: 254 data bytes per sector.
;
;          status: 0000000X .......... Ok.
;     		 * 00000010 .......... File not found.
;	           00011111 .......... EOI (END OF FILE)
;		   (Followed by number of bytes to follow)
;		  
;	         * Controller status in the range (3-15) should 
;		   be considered an error.
;
;
;
;
;
;
;
;
;  BREAK DOWN OF STATUS BYTE  (Burst Commands 1-8)
;
;                  MD DN I1 I2 D1 D2 D3 D4
;
;                      MD ............ Mode: 1 = MFM, 0 = GCR.
;                      DN ............ Drive Number.
;                      I1, I2 ........ Sector Size.
;                             a) 00 = 128 bytes
;                             b) 01 = 256 bytes
;                             c) 10 = 512 bytes
;                             d) 11 = 1024 bytes

;                      D1-D4 ........ Controller Status
;
;                  GCR
;
;                      000x = Ok.
;                      0010 = Sector not found.
;                      0011 = No Sync.
;                      0100 = Data block not found.
;                      0101 = Data block checksum.
;                      0110 = Format error.
;                      0111 = Verify error.
;                      1000 = Write protect error.
;                      1001 = Header block checksum.
;                      1010 = Data extends into next
;                             block.
;                      1011 = Disk ID mismatch/Disk change.
;                      1100 = Unused.
;                      1101 = Unused.
;                      1110 = Syntax.
;                      1111 = No Drive present.
;         
;
;
;                  MFM
;
;                      000x = Ok.
;                      0010 = Sector not found.
;                      0011 = No address mark.
;                      0100 = Unused.
;                      0101 = Data CRC error.
;                      0110 = Format error.
;                      0111 = Verify error.
;                      1000 = Write protect error.
;                      1001 = Header CRC error.
;                      1010 = Unused.
;                      1011 = Disk change.
;                      1100 = Unused.
;                      1101 = Unused.
;                      1110 = Syntax.
;                      1111 = No Drive present.
	.page
; (1) fast read 

; 0   1    2     3      4    5        6   +  (cmdbuf)
; ^   ^    ^     ^      ^    ^        ^  
; U   0    N    trk   sec   #sec   nexttrack(optional)
        

fstrd   sta  cmd	; save command for dos
	sta  ctl_cmd	; save command for stbctt
	
        bit  lock	; channel open ?
        bvs  frd_00	

	ldx  #%00001011 ; no channel
	.byte skip2
ndkrd	ldx  #%01001111 ; no drive

fail	jsr  upinst     ; update dkmode
	jsr  statqy	; wait for state handshake
final	cpx  #2
	bcs  exbad

	rts

exbad   txa             ; retrieve status
	and  #15	; bits 0-3 only
	ldx  #0         ; jobnum
        jmp  error      ; controller error entry
  

frd_00	jsr  spout       

	bit  dkmode     ; gcr or mfm ?
        bpl  rdgcr


; 	MFM READ 

	lda  #9         ; read cmd
        jmp prcmd       

rdgcr	jsr  autoi      ; check for auto init

frd_01	cli             ; let controller run
	lda  switch	; check for B
	and  #%00100000
	bne  bfonly

        lda  cmdbuf+3   ; get track
        sta  hdrs        
        lda  cmdbuf+4   ; get sector
        sta  hdrs+1      
        ldx  #0         ; job #0
        lda  ctl_cmd    ; read ($80) or fread ($88)
        sta  jobs,x      
	jsr  stbctt     ; hit controller hard

        sei      	; disable irqs
	jsr  upinst	; update controller status

	bit  switch	; check E
	bvs  igerr	

        cpx  #2         ; error
        bcs  fail

igerr   jsr  hskrd      ; handshake on state of clkin

	lda  switch	; check B
	bmi  notran

bfonly  ldy  #0         ; even page
frd_02	lda  $0300,y    ; get data
        sta  ctl_dat    ; setup data
        jsr  hskrd      ; handshake on state
        iny      
        bne  frd_02

notran	dec  cmdbuf+5   ; any more sectors ?
        beq  exrd        

        jsr  sektr      ; next sector
        jmp  frd_01	; more to do

exrd    cli
        jmp  chksee     ; next track ?

	.page
; (2) fast write 

; 0   1    2     3      4    5        6   +  (cmdbuf)
; ^   ^    ^     ^      ^    ^        ^  
; U   0    N    trk   sec   #sec   nexttrack(optional)

fstwrt  sta  cmd        ; save command for dos
        bit  lock	; channel open ?
        bvs  fwrt_0	

	ldx  #%00001011	; no channel
	.byte  skip2
ndkwrt	ldx  #%01001111	; no drv 1
	stx  ctl_dat	; save status
	lda  switch	; set internal switch
        ora  #%00001000
	sta  switch

fwrt_0  bit  dkmode     ; gcr or mfm ?
        bpl  wrtgcr


;	MFM WRITE

	lda  #10
	jmp  prcmd	

wrtgcr	jsr  autoi      ; chk for autoi
	
	lda  switch	; transmision required
	bmi  notrx

fwrt_1	sei             ; no irqs
	ldy  #0         ; even page
fwrt_2  lda  pb		; debounce
        eor  #clkout    ; toggle state of clock
	bit  icr	; clear pending
        sta  pb
fwrt_3	jsr  tstatn     ; chk for atn
fwrt_4	lda  pb
        bmi  fwrt_3	; attn low ?

        lda  icr	; wait for byte
        and  #8
        beq  fwrt_4	; chk for attn low only

        lda  sdr	; get data
        sta  $0300,y    ; put away data
        iny      
        bne  fwrt_2	; more ?

	jsr  clkhi	; release clock
notrx   cli             ; let controller run
	lda  switch	; check for buffer transfer only
	and  #%00100000
	bne  nowrt

	lda  switch	; check internal
	and  #%00001000
	beq  notrx0	; br, ok...

	ldx  ctl_dat	; get error
	jmp  fail	; abort

notrx0  lda  cmdbuf+3   ; get track
        sta  hdrs        
        lda  cmdbuf+4   ; get sector
        sta  hdrs+1      
        ldx  #0         ; job #0
	lda  ctl_cmd	; get write job
        sta  jobs,x      
        jsr  stbctt     ; wack controller in the head

        sei             ; no irqs ok !
        jsr  spout      ; go output
	jsr  upinst	; update status
        jsr  hskrd	; send it
	jsr  burst	; wait for reverse
	jsr  spinp
        cli             ; irqs ok now
        
	bit  switch	; check error abort switch
	bvs  nowrt

        cpx  #2         ; error on job ?
        bcs  fwrt_5	; abort ?

nowrt   dec  cmdbuf+5   ; more sectors ?
        beq  fwrt_6

        jsr  sektr      ; increment sector
        jmp  fwrt_1

fwrt_5	jmp  exbad

fwrt_6  cli		; done
	jmp  chksee	; next track ?

	.page
; (3) fast seek

; 0   1    2    
; ^   ^    ^   
; U   0    N   

fstsek  lda  cmdbuf+2	; check drive number
	and  #1
        bne  3$		; drive 1 - error

	lda  #5		; read address cmd
	jsr  prcmd	; give it to controller
	
	ldx  mfmcmd	; get status
	cpx  #2		; ok ?
	bcc  2$

	ldx  #0
	stx  dkmode 	; force gcr,drv0,ok
	lda  #seek	; seek
	sta  cmd	; give command to dos
	sta  jobs,x	; give job to controller
	jsr  stbctt	; bang the controller
	.byte  skip2	; return status
3$	ldx  #%01001111 ; no drv 1
2$	jmp  fail	; update status

	.page
; (4) burst format mfm/gcr

; 0   1    2    3	4
; ^   ^    ^    ^       ^
; U   0    N    ID     ID

fstfmt  lda  cmdbuf+2   ; check drive number
	and  #1
	bne  1$

	lda  cmdbuf+3	; format gcr or mfm ?
	bpl  2$


;       FORMAT IN MFM

	lda  #8		; format disk in mfm
	jmp  prcmd

2$	lda  #0
	sta  dkmode     ; force GCR,DRV0
	sta  nodrv	; drive ok
	lda  cmdbuf+4
	sta  dskid	; low id
	lda  cmdbuf+5
	sta  dskid+1	; high id
	
	jsr  clrchn	; close all channels
	lda  #1
	sta  track	; track one

        jsr  ptch28	; format now

	tax		; save error
	ldx  #%01001111
	.byte skip2
	jsr  upinst	; update status
	jmp  final	; finish up ...
	
	.page
; (5) SOFT INTERLEAVE

; 0   1    2     3 
; ^   ^    ^     ^    
; U   0    N    INT

cpmint  sei
	bit  switch	; read ?
	bpl  1$		; br, write

	jsr  spout  	; serial port output
	lda  cpmit	; get current interleave
	sta  ctl_dat	; send it
	jmp  hskrd

1$	ldx  cmdsiz      
        cpx  #4
        bcs  2$

	ldx  #%00001110 ; syntax
	jsr  upinst	; update dkmode

        lda  #badcmd     
        jmp  cmderr      

2$	lda  cmdbuf+3
	sta  cpmit      ; save
        rts      
	.page
; (6) query disk format

; 0   1    2    3
; ^   ^    ^    ^
; U   0    N   STP (opt)

; status / status / cpmsek / logical_track / min_sector / max_sector / hardint
; mfm/gcr   mfm      mfm          mfm           mfm          mfm        mfm

querdk  jsr  fstsek	; check disk format
	bit  dkmode	; mfm or gcr ?
	bpl  2$
	
	lda  #13
	jsr  prcmd	; generate sector table

	ldx  mfmcmd	; status ok ?
	cpx  #2
	bcs  1$

	jsr  maxmin	; determine low/high sector
	jsr  fn_int	; determine interleave
	txa		; hard interleave 
	pha		; save it

1$	sei		; no irq's
	jsr  spout	; serial port output
	lda  dkmode	; get status and send it
	sta  ctl_dat
	jsr  hskrd	; transmit status

	ldx  mfmcmd	; was status ok ?
	cpx  #2
	bcs  2$

	lda  cpmsek	; get number of sectors
	sta  ctl_dat	
	jsr  hskrd	; send it

	lda  cmd_trk	; get logical track number
	sta  ctl_dat
	jsr  hskrd	; send track

	lda  minsek
	sta  ctl_dat	; send min.
	jsr  hskrd	; wait for handshake

	lda  maxsek	; send max.
	sta  ctl_dat
	jsr  hskrd	; wait for handshake

	pla		; get interleave
	sta  ctl_dat	; send interleave
	jsr  hskrd	; wait for handshake

2$	rts	

	.page
; (7) query/init status

; 0   1    2     3      
; ^   ^    ^     ^
; U   0    N   STAT


inqst   bit  switch	; read/write op ?
	bpl  wrstat

statqy  sei 		; disable irqs
	jsr  spout      ; serial port out
	lda  dkmode 	; get status
	sta  ctl_dat	
	jsr  hskrd	; 6526 will send it	

	lda  #0
	sta  erword
	
exchnl  jsr  spinp	; serial port input
exchn2	cli
	rts

wrstat	lda  cmdbuf+3	; new value
	sta  dkmode	
	rts

	.page
; (8) backup disk

; 0   1    2     3      
; ^   ^    ^     ^      
; U   0    N    DEST.DRV

duplc1  ldx  #%00001110
	jsr  upinst	; update dkmode
	
	lda  #badcmd
	jmp  cmderr

	.page
;       subroutines

;******************************************************
	
chksee  lda  cmdsiz     ; chk for next track
        cmp  #7          
        bcc  1$

	ldy  hdrs	; where are we ?
	dey		; one less
	tya
	asl  a		; *2
	sta  cur_trk
        ldy  cmdbuf+6   ; get next track
        sty  hdrs       ; give track to controller
	dey
	sty  cmd_trk	; update track
	jmp  seke	

1$	rts      

;******************************************************

upinst  stx  ctl_dat
	lda  dkmode     ; update main status w/ controller status
        and  #%11110000 ; clear old controller status
        ora  ctl_dat    ; or in controller status
        sta  dkmode     ; updated
	sta  ctl_dat
	rts

;******************************************************

hskrd   jsr  tstatn     ; test for atn

1$	lda  pb		; debounce
        cmp  pb
        bne  1$

        bmi  hskrd      ; attn low ?

        eor  fastsr     ; wait for state chg
        and  #4          
        beq  1$

hsksnd  lda  ctl_dat    ; retrieve data
        sta  sdr	; send it
        lda  fastsr      
        eor  #4         ; change state of clk
        sta  fastsr      
        lda  #8
1$	bit  icr	; wait transmission time
        beq  1$

        rts      

;******************************************************

sektr   ldx  cmdbuf+3   ; get track
	lda  num_sec-1,x
	tax
	dex
        stx  ctl_dat    ; save
	clc
        lda  cmdbuf+4   ; get sector
        adc  cpmit      ; add interleave
        cmp  ctl_dat    ; less than maxsec ?
        bcc  gtsec       
        sbc  ctl_dat    ; rap around
        beq  oksec      ; special case on max
        sec      
        sbc  #1         ; less one
	.byte skip2
oksec   lda  ctl_dat      
gtsec   sta  cmdbuf+4   ; new sector
        lda  #fread     ; exread job
        sta  ctl_cmd      
        rts      

;******************************************************

stbctt  php
	cli
	jsr  stbctl     ; strobe controller
        cmp  #2         ; was there an error ?
        bcc  1$		; br, nope

	ldx  #0
	stx  jobnum	; set job #
	lda  cmdbuf+2	; get command
	sta  ctl_cmd	; reset command
	sta  cmd	; set for dos
	sta  lstjob,x	; set last job
	sta  jobs	; give it to the controller
	jsr  stbctl	; wait for it
	jsr  watjob	; let dos clean it up
        lda  jobs       ; get error return
	cmp  #2		; set/clr carry
1$	plp
	tax     	; return status in .x
	bcc  2$

        lda  cmdbuf+3    
        sta  track      ; give track
        lda  cmdbuf+4    
        sta  sector     ; give sector
	jmp  3$		; update DOS

2$	lda  #0
	sta  jobrtn	; clr job return flag

3$	txa		; restore .a
        rts      

;******************************************************

burst	jsr  tstatn     ; test for atn
1$	lda  pb		; debounce
        cmp  pb
        bne  1$		; same ?

        bmi  burst	; attn low ?

        eor  fastsr     ; wait for state chg
        and  #4          
        beq  1$
	
	lda  fastsr
	eor  #4
	sta  fastsr     ; state change
	rts

;******************************************************