;Read from controller memory
writem	equ	0A1h		;Write to controller memory

;Define stepping rate equates
;----------------------------
;
dmfste	equ	3*341/10	;SA851 stepping rate constant
dmfset	equ	15*341/10	;SA851 settling rate constant

;Define Internal status byte fields
;----------------------------------
;
dms$t0	equ	01000000b	;Track 0 status mask  (1 = on trk 0)
dms$dd	equ	00100000b	;Double density mask  (1 = double)
dms$wr	equ	00010000b	;Double sided track wrap  (1 = wrap)
dms$ds	equ	00001000b	;Double sided status mask  (1 = double)
dms$hs	equ	00000100b	;Hard sectored status mask  (1 = hard)
dms$ss	equ	00000011b	;Sector size code mask ...
				;... 0 = 128, 1 = 256, 2 = 512, 3 = 1024

;Define North Star status byte fields
;------------------------------------
;
dmn$dä	eqõ	10000000â	;Doublå densitù mask
dmn$ds	equ	01000000b	;Double sided mask
dmn$2x	equ	00100000b	;CP/M version 2.x mask
dmn$ok	equ	00010000b	;Validation mask
dmn$40	equ	00001000b	;40/80 track mask
dmn$dt	equ	00000100b	;Double track density mask
dmn$xx	equ	00000011b	;RFU mask

;Common Subroutines
;------------------


; Return a pointer to the current drives drive parameter entry
;-------------------------------------------------------------
;
dmdpar:	lhld	dmdriv			;Get the current drive number
	mvi	h,0			;Drive number is a byte
	dad	h			;Ten bytes per parameter table entry
	mov	d,h
	mov	e,l
	dad	h
	dad	h
	dad	d
	lxi	d,dparam		;Parameter table address
	dad	d
	ret

	page

	if	maxdm ne 0	;Start 8" drive's unique code section
;====================================================================	
;Devicå Specificatioî Tablå foò DJDMA controlleò witè ¸" drives
;==============================================================
;
dmdst:	db	maxdm			;Number of logical drives
	dw	dmwarm			;Warm boot
	dw	dmtran			;Sector translation
	dw	dmldr1			;Select drive 1
	dw	dmldr2			;Select drive 2
	dw	dmhome			;Home drive
	dw	dmseek			;Seek to specified track
	dw	dmsec			;Set sector
	dw	dmdma			;Set DMA address
	dw	dmread			;Read a sector
	dw	dmwrit			;Write a sector
	dw	nobad			;No bad sector map

	if	dmorder ne 1		;no warm boot possible

;DJDMA 8" warm boot dummy
;------------------------
;	1) If 8" DJDMA is not drive A (i.e. dmorder not equal 1) then
;	   it is not possible to warm boot from 8". So routine not needed.
;
dmwarm:	ret				;return if called

	else

;DJDMÁ 8¢ warí booô loader
;-------------------------
;	1) Thió loadeò loadó froí thå starô oæ thå CCÐ (tracë ° sectoò 5©
;	   tï thå enä oæ thå BDOÓ (tracë ± sector 3)®  Onlù 76¸ (3/4k© byteó
;	   oæ tracë ± sectoò ³ ió reaä iî since thå warí booô routinå ió
;	   noô alloweä tï loaä anù thå CBIOÓ code.
;	2) Sectoò ³ ió reaä intï thå disë buffeò anä copieä intï itó propeò
;	   restinç place.
;
dmcod8	equ	22*128			;Amount of code on track 0 to load

dmwarm:	call	dmsel2			;Select drive 0
dmwbad:	lxi	h,dmwchn		;Warm boot command channel
	lxi	d,dmwoff
	call	dmcmd			;Execute the channel
	jnz	dmwbad			;Retry
	lda	dmwst0			;Get track read status
	lhld	dmwst1			;Track ones status in L
	ora	l
	cpi	40h
	jnz	dmwbad			;Loop on 'terrible' errors like no disk

	lxi	b,300h			;Move .75 Kbytes of sector 3
	lxi	d,buffer		;Sector 3 is in our buffer
	lxi	h,ccp+1300h		;  and this is where we want it to go
	call	movbyt
	xra	a
	ret

dmwchn:	db	dmsdma			;Set track 0 DMA address
	dw	ccp-512			;First track DMA address - boot loader
	db	0
	db	rdtrck			;Read track command
	db	0			;Track 0
	db	0			;Side 0
	db	0			;Drive 0
	dw	dmwmap			;Sector load/status map
	db	0
dmwst0:	db	0			;Track read status
	db	dmsdma
	dw	ccp+dmcod8		;DMA address for track 1
	db	0
	db	rdtrck
	db	1			;Track 1
	db	0			;Side 0
	db	0			;Drive 0
	dw	dmwmap+26		;Load map right after track 0 map
	db	0
dmwst1:	db	0			;Track read status
	db	dmsdma
	dw	buffer			;Sector 3 gets loaded in system buffer
	db	0
	db	dmrsec
	db	1			;Track 1
	db	3			;Side 0, sector 3
	db	0			;Drive 0
	db	0			;Read status
	db	dmhalt			;Controller halt command
	db	0

dmwoff	equ	$-dmwchn-1		;Halt offset for the command channel

dmwmap:	dw	-1, -1, 0, 0, 0, 0, 0	;Do not load the boot loader
	dw	0, 0, 0, 0, 0, 0

	dw	0, -1, -1, -1		;First 2 sectors on track 2

	endif				;end of 8" DJDMA warm boot

;DJDMA 8" sector translation
;---------------------------
;
dmtran:	inx	b			;Ajust sectors to start at 1
	lda	dmpsta			;Test for double sided drives
	ani	dms$ds
	jz	dmtrn0			;Skip if single sided
	lda	dmcspt			;Get SPT/2
	sub	c			;Test for side one sectors
	jnc	dmtrn0			;Skip sector adjustment if on side zero
	cma				;'Knock off' first sides sectors
	inr	a
	mov	c,a
	mvi	b,80h			;Set side one flag
dmtrn0:	mov	l,c			;Make an index to the SECTRAN table
	mvi	h,0
	dad	d
	mov	l,m			;Load the translated sector
	mov	h,b			;Set the side bit
	ret

;DJDMÁ 8¢ drivå selecô 1
;-----------------------
;	1) Determinå thå sectoò sizå anä thå numbeò oæ sideó oî thå drive®
;	2) Returî correcô DPH.
;
dmldr1:	call	dmsel2			;Do logical select	
	call	dminit			;Test for a controller
	jc	zret			;Skip if no controller present

	call	dmstat			;Accm:= Djdma_returned_Drive_Status
	jc	zret			;Skip on status check error
	push	psw
	ani	dms$t0			;Check for track 0
	jz	dmldr0			;Skip if not on track 0 (status valid)

	pop	psw			;Clean stack
	lxi	h,1			;read sector 1 ...
	shld	truesec
	inx	h			;... of track 2
	shld	cpmtrk			;because track 1 always single density
	xra	a
	sta	rdwr			;force read to get valid drive status
	call	fill			;flush buffer and read
	jc	zret			;exit with error if error

	call	dmdpar			;Get the drive parameter address
	inx	h
	mvi	m,0			;Decalibrate the drive
	call	dmparm
	call	dmstat			;Accm:= Djdma_returned_Drive_Status
	jc	zret			;If (error eq true) goto error_return
	push	psw

dmldr0:	pop	psw			;Get drive status
	sta	dmpsta			;Set the physical status mode
	call	dmsptr			;Save status in status table
	mov	m,a

	ani	dms$ss			;Mask in sector size bits
	rlc				;Make a word index
	push	psw			;Used to select a DPB
	mov	e,a
	mvi	d,0
	lxi	h,xlts			;Table of XLT table pointers
	dad	d
	push	h			;Save pointer to proper XLT

	call	dmgdph			;Get a pointer to the drives DPH
	pop	d			;Copy XLT pointer from table to DPH
	lxi	b,2
	call	movbyt
	lxi	d,8			;Offset to DPB pointer
	dad	d

	push	h
	lda	dmpsta			;Test for a double sided drive
	ani	dms$ds
	lxi	d,dpb128s		;Base for single sided DPB's
	jz	dmsok
	call	dmfstp			;Set controller to fast steping mode
	lxi	d,dpb128d		;Base of double sided DPB's
dmsok:	xchg
	poð	ä			;Restorå DPH pointeò to DPB
	pop	psw			;Offset to correct DPB (sector size)

	rlc				;Times   4
	rlc				;	 8
	rlc				;	16 bytes per DPB

	mov	c,a			;Offset to the correct DPB
	mvi	b,0
	dad	b
	xchg				;Load the DPB pointer in the DPH
	mov	m,e
	inx	h
	mov	m,d

	lxi	h,15			;Offset to the sector size code
	dad	d
	mov	c,m

dmgdph:	lda	dmdriv			;Get the DPH pointer
	lxi	d,dphdm0
	call	retdph
	ret

;DJDMÁ 8¢ drivå selecô 2
;-----------------------
;	1) Figurå numbeò oæ sectoró_peò_trac믲 foò SECTRAN.							;
;
dmldr2:	call	dmsel2			;Perform logical drive select
	call	dmgdph			;Load the DPH pointer
	lxi	d,10			;Offset to the DPB pointer
	dad	d
	mov	a,m			;Load the DPB pointer
	inx	h
	mov	h,m
	mov	l,a
	mov	a,m			;Load the number of CP/M sectors/track
	rrc				;Divide by two
	sta	dmcspt			;Save CPM SPT
	ret

;Set the drive's step rate to 3ms
;--------------------------------
;	1) Thå currenô drivå ió doublå sided®  Thuó ió iô safå tï seô thå
;	   steppinç ratå tï ³ mó witè 1µ mó settling.
;
dmfstp:	call	dmdpar			;Get the parameter table pointer
	inx	h			;Bump to the drive initialized flag
	mvi	m,0			;Force reparamitization of this drive
	inx	h			;Offset to the Stepping rate constant
	mvi	m,(low dmfste)		;Fast stepping rate constant
	inx	h
	mvi	m,(high dmfste)
	lxi	d,5			;Skip over the reserved fields
	dad	d
	mvi	m,(low dmfset)		;Fast settling rate constant
	inx	h
	mvi	m,(high dmfset)
	call	dmparm			;Set drive parameters for the SA850
	ret

;DJDMA 8" driver variables
;--- °
;	   sidå 1).
;
mfseek:	xra	a			;Clear double sided select flag
	sta	mfsid1
	lxi	h,dmpsta		;Get the drive status
	mov	a,m
	ani	dms$hs			;Test for hard sectored drives
	jz	dmsoft			;Skip if soft sectored

	mov	a,m			;Test for double sided drives
	ani	dms$ds
	jz	dmseek			;Skip if single sided

	mov	a,m			;Test for track wrap mode
	ani	dms$wr
	jz	dmseek			;Skip if not wrapping

	mov	a,c			;Test for tracks 35-69
	cpi	35
	jc	dmseek			;Skip if less than track 35

	mvi	a,69			;Adjust tracks 35 -> 69 to 34 -> 0
	sub	c
	mov	c,a
	mvi	a,080h			;Set side one flag
	sta	mfsid1
	jmp	dmseek

dmsoft:	mov	a,m			;get drive status again
	ani	dms$ds			;check for double sided (cy = 0)
	jz	dmseek			;skip if not double sided

	mov	a,c			;get track number
	rar				;divide by 2 for Morrow soft sectored
	mov	c,a
	jnc	dmseek			;skip if on side 1
	mvi	a,80h
	sta	mfsid1			;else indicate side 2
	jmp	dmseek

;DJDMA 5.25" set sector
;----------------------
;
mfssec:	lda	dmpsta			;if (drive .eq. soft_sectored)
	ani	dms$hs			;	goto sector save routine
	jz	dmsec			;else
	dcr	c			;	adjust for first sect = zero
	jmp	dmsec

;DJDMA 5.25" read/write sector
;-----------------------------
;
mfread:	call	mfset			;Set up side flag
	jmp	dmread

mfwrit:	call	mfset			;Set up side flag
	jmp	dmwrit

mfset:	lda	mfsid1			;Get the side flag
	lxi	h,dmsctr		;Merge with the sector number
	ora	m
	mov	m,a
	ret

;DJDMA 5.25" driver variables
;----------------------------
;
;Mini-Floppy Configuration/DPB_Lookup table
;	1) This table is used by the mini-floppy first time select routine
;	   (mfsldr1) and is used to:
;		a) validate the drive configuration byte.
;		b) fill in the parameters that can't be determined by doing
;		   sense drive status (like sensing double sided drives).
;		c) returning a pointer to the proper DPB for the media.
;	2) There are four fields per entry.
;		Field_1: Drive configuration byte.
;		Field_2: Additional drive parameters that can't be determined
;			 by doing a sense drive status (i.e. double_sided and
;			 track_wrap).
;		Field_3: Pointer to the appropriate DPB
;
mfs:	db	10h			;North Star CP/M 1.4
	db	0			;Single density, 35 tracks, 1-sided
	dw	dpbmf0			;1K groups

	db	90h			;North Star CP/M 1.4
	db	0			;Double density, 35 tracks, 1-sided
	dw	dpbmf1			;1K groups

	db	0b0h			;North Star CP/M 2.x
	db	0			;Double density, 35 tracks, 1-sided
	dw	dpbmf2			;2K groups

	db	0f0h			;North Star CP/M 2.x
	db	(dms$ds or dms$wr)	;Double density, 35 tracks, 2-sided
	dw	dpbmf3			;2K groups

	db	0a0h			;North Star CP/M 2.x  (fake 40 track)
	db	0			;Double density, 35 tracks, 1-sided
	dw	dpbmf2			;2K groups

	db	0d0h			;North Star CP/M 2.x (fake 40 track)
	db	(dms$ds or dms$wr)	;Double density, 35 tracks, 2-sided
	dw	dpbmf3			;2K groups

	db	0a1h			;Morrow Designs CP/M 2.x Soft sectored
	db	0			;Double density, 40 tracks, 1-sided
	dw	dpbmf4

	db	0a9h			;Morrow Designs CP/M 2.x Soft sectored
	db	dms$ds			;Double density, 40 tracks, 2-sided
	dw	dpbmf5

	db	0			;End of configuration table

; Hard sectored single sided sector translation table
;
mfxlts:	db	 1,  2
	db	 3,  4
	db	 5,  6
	db	 7,  8
	db	 9, 10
	db	11, 12
	db	13, 14
	db	15, 16
	db	17, 18
	db	19, 20

; Hard sectored double sided sector translation table
;
mfxltd:	db	 1,  2,  3,  4
	db	21, 22, 23, 24
	db	 5,  6,  7,  8
	db	25, 26, 27, 28
	db	 9, 10, 11, 12
	db	29, 30, 31, 32
	db	13, 14, 15, 16
	db	33, 34, 35, 36
	db	17, 18, 19, 20
	db	37, 38, 39, 40

; Soft sectored single sided translation table
;
mfxlt1:	db	 1,  2,  3,  4,  5,  6,  7,  8
	db	25, 26, 27, 28, 29, 30, 31, 32
	db	 9, 10, 11, 12, 13, 14, 15, 16
	db	33, 34, 35, 36, 37, 38, 39, 40
	db	17, 18, 19, 20, 21, 22, 23, 24

mfsid1:	db	0		;On side one flag

;disk parameter headers
;----------------------
;
dphmf0:	dw	0		;translation table address
	dw	0
	dw	0
	dw	0
	dw	dirbuf		;directory buffer
	dw	dpbmf0		;pointer to disk parameter block
	dw	csvmf0		;scratch pad area for checking changed disks