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Commodore 1571 firmware
Fast load

        .page  
	.subttl 'fastld.src'

fstload jsr  spout	; output
	jsr  set_fil	; setup filename for parser
	bcs  9$

        jsr  autoi	; init mechanism
	lda  nodrv	; chk status
	bne  9$		; no drive status

	lda  fastsr	; set error recovery flag on
	ora  #$81	; & eoi flag
	sta  fastsr	
	jsr  findbuf	; check for buffer availabilty

	lda  cmdbuf
	cmp  #'*	; load last ?
	bne  7$
	
	lda  prgtrk	; any file ?
	beq  7$

	pha		; save track
	lda  prgsec
	sta  filsec	; update
	pla
	jmp  1$

7$	lda  #0          
	tay
	tax		; clear .a, .x, .y
        sta  lstdrv     ; init drive number
	sta  filtbl	; set up for file name parser
        jsr  onedrv     ; select drive
	lda  f2cnt
	pha	
	lda  #1
	sta  f2cnt
	lda  #$ff
	sta  r0		; set flag
	jsr  lookup	; locate file
	pla		 
	sta  f2cnt	; restore var
	lda  fastsr
	and  #$7f	; clr error recovery flag
	sta  fastsr
	bit  switch	; seq flag set ?
	bmi  8$

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

; 	lda  pattyp	; is it a program file ?
;	cmp  #2
	jsr  ptch56	; *** rom ds 85 ***
	nop		; fill

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

	bne  6$		; not prg

8$      lda  filtrk     ; check if found. err if not
        bne  1$		; br, file found

6$    	ldx  #%00000010	; file not found
	.byte skip2
9$	ldx  #%00001111	; no drive
        jmp  sys_err	

1$      sta  prgtrk	; save for next
	pha		; save track
	jsr  set_buf	; setup buffer allocation
	pla		; get track
	ldx  channel	; get channel offset
	sta  hdrs,x	; setup track
        lda  filsec     ; & sector
	sta  prgsec	; for next time
        sta  hdrs+1,x

	lda  #read	; read job
	sta  cmdbuf+2	; save read cmd
	sta  ctl_cmd	

2$	cli		; let controller run
	ldx  jobnum	; get job #
	lda  ctl_cmd	; get cmd
	sta  jobs,x	; send cmd
	jsr  stbctr	; whack the controller in the head
	cpx  #2		; error ?
	bcc  5$
	
	jmp  ctr_err

5$	sei
	ldy  #0
	lda  (dirbuf),y	; check status
	beq  end_of_file	

	lda  fastsr	; clear flag
	and  #$fe
	sta  fastsr

	jsr  handsk	; handshake error to the host

	ldy  #2
3$	lda  (dirbuf),y
	tax		; save data in .x
	jsr  handsk	; handshake it to the host
	iny
	bne  3$

	ldx  channel	; jobnum * 2
	lda  (dirbuf),y ; .y = 0
	cmp  hdrs,x	; same as previous track ?
	beq  4$

	ldy  #read
	.byte skip2
4$	ldy  #fread	; fast read
	sty  ctl_cmd	; command to seek then read
	sta  hdrs,x	; next track
	ldy  #1		; sector entry
	lda  (dirbuf),y	
	sta  hdrs+1,x	; next sector	
	jmp  2$


end_of_file
	ldx  #$1f	; eof
	jsr  handsk	; handshake it to the host

	lda  #1
	bit  fastsr	; first time through ?
	beq  1$	        ; br, nope

	tay		; .y = 1
	lda  (dirbuf),y	; number of bytes
	sec
	sbc  #3
	sta  ctl_dat	; save it
	tax		; send it
	jsr  handsk	; handshake it to the host

	iny		; next
	lda  (dirbuf),y	; address low
	tax
	jsr  handsk	; handshake it to the host

	iny
	lda  (dirbuf),y	; address high
	tax
	jsr  handsk	; handshake it to the host
	ldy  #4		; skip addresses
	bne  3$		; bra

1$      ldy  #1
	lda  (dirbuf),y	; number of bytes
	tax
	dex
	stx  ctl_dat	; save here
	jsr  handsk	; handshake it to the host

	ldy  #2		; start at data
3$	lda  (dirbuf),y
	tax
	jsr  handsk	; handshake it to the host
	iny
	dec  ctl_dat	; use it as a temp
	bne  3$

	lda  #0
	sta  sa
	jsr  close	; close channel	(faux)
	jmp  endcmd
;
;
;
; *************************
; ***** ERROR HANDLER *****
; *************************

ctr_err sei		; no irq's
	stx  ctl_dat	; save status here
	jsr  handsk	; handshake it to the host
	lda  #0
	sta  sa
	jsr  close	; close channel (faux)
	ldx  jobnum
	lda  ctl_dat	; get error
	jmp  error	; error out.....	

sys_err sei
	stx  ctl_dat	; save error
	ldx  #2		; file not found 
	jsr  handsk	; give it to him
	lda  #0
	sta  sa
	jsr  close	; close channel (faux)
	lda  ctl_dat	; get error back
	cmp  #2
	beq  1$

	lda  #nodriv	; no active drive
	.byte skip2
1$	lda  #flntfd	; file not found
	jmp  cmderr	; never more...
;
;
;
; *************************************
; ***** FIND INTERNAL READ BUFFER *****
; *************************************

findbuf lda  #0
	sta  sa		; psydo-load 
	lda  #1		; 1 buffer
	jsr  getrch	; find a read channel
	tax
	lda  bufind,x	; get buffer
	sta  dirbuf+1	; set it up indirect
	rts	
;
;
;
; **************************************
; ***** SETUP INTERNAL READ BUFFER *****
; **************************************

set_buf lda  dirbuf+1	; index to determine job
	sec
	sbc  #3
	sta  jobnum	; save in jobnum
	asl  a
	sta  channel	; save channel off
	lda  #0
	sta  dirbuf	; even page boundary
	rts
;
;
;
; *************************************
; ***** FAST LOAD FILENAME PARSER *****
; *************************************

set_fil ldy  #3		; default .y
	lda  cmdsiz	; delete burst load command
	sec
	sbc  #3
	sta  cmdsiz	; new command size

	lda  cmdbuf+4   ; drv # given ?
	cmp  #':
	bne  1$

	lda  cmdbuf+3
	tax		; save 
	and  #'0
	cmp  #'0        ; 0:file ?
	bne  1$

	cpx  #'1	; chk for error
	beq  4$			

1$	lda  cmdbuf+3   ; drv # given ?
	cmp  #':
	bne  2$

	dec  cmdsiz
	iny

2$	ldx  #0		; start at cmdbuf+0
3$      lda  cmdbuf,y	; extract file-name
	sta  cmdbuf,x
	iny
	inx
	cpx  cmdsiz	; done ?
	bne  3$		; delete cmd from buffer

	clc
	.byte skip1
4$	sec		; error
	rts



handsk			; .x contains data
1$	lda  pb		; debounce
        cmp  pb
        bne  1$

	and  #$ff	; sclr neg flag
        bmi  3$		; br, attn low 

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

        stx  sdr	; send it
        lda  fastsr      
        eor  #4         ; change state of clk
        sta  fastsr      

        lda  #8
2$	bit  icr	; wait transmission time
        beq  2$

        rts      

3$	jmp  ptch30	; bye-bye the host wants us


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