TITLE	ADVANCED DIGITAL LOADER BIOS FOR SUPER QUAD Oct 15 1982 08:00

;*****************************************************************
;**								**
;**		ADVANCED DIGITAL SUPER QUAD Z80 SBC		**
;**								**
;**			   LOADER BIOS				**
;**								**
;**	This bios contains drivers for:				**
;**								**
;**		Floppy disk or					**
;**		Hard disk					**
;**		Serial input & output				**
;**								**
;**	Written by:						**
;**								**
;**		Scott Carter					**
;**		Greg Lindberg					**
;**								**
;*****************************************************************


	SUBTTL	Customization Equates
page	60
	.z80
true	equ	0ffffh
false	equ	0

mini	equ	false		;true for minifloppy BIOS
special equ	false		;true for 8"-5" special board
m48tpi	equ	false		;true for 48tpi mini drives
m96tpi	equ	false		;true for 96tpi mini drives
nmbfpy	equ	2		;number of floppy disk drives

;------------------------------------------------------------------------
;	This is the seek rate constant!!  seekrt, below, is an offset!
	seekrate equ	0		;6ms for 8", 12ms for 5"
					;seek rate 0=3ms, 1=6ms, 2=10ms, 3=15ms
					;these times double for minifloppies

;***   Hard Disk selection choices   ***
ST503	EQU	1		; Seagate Technology ST503
ST506	EQU	2
TM601S	EQU	3		; Tandon Magnetics TM601S
TM602S	EQU	4
TM603S	EQU	5
TM603SE	EQU	6
TM501	EQU	7		; Tandon Magnetics TM501
TM502	EQU	8
TM503	EQU	9
SA602	EQU	10		; Shugart Associates SA602
SA604	EQU	11
SA606	EQU	12
SA1002	EQU	13		; Shugart Associates SA1002
SA1004	EQU	14
Q2010	EQU	15		; Quantum Q2010
Q2020	EQU	16
Q2030	EQU	17
Q2040	EQU	18
M4010	EQU	19		; MiniScribe 4010
M4020	EQU	20

;***   HDC1001 Physical drives ***
hd0	equ	SA1002		; Set to type of drive or false if not used

	SUBTTL	SYMBOLIC EQUATES
	page
;	board hardware equates
cmd	equ	0ch		;fdc command register
trk	equ	cmd+1		;track register
sec	equ	cmd+2		;sector register
data	equ	cmd+3		;data register
wait	equ	14h		;INTRQ and DRQ synch port (see manual)

memry	equ	16h		;memory control port
;
;	sector deblocking equates
;
hstcnt	equ	8		;number of sectors in buffer
hstshft equ	3		;shift factor for # of sectors in buffer

	if	mini 
ddpspt	equ	4		;double density physical sectors per track
	if	m48tpi
tracks	equ	39		;minifloppies
	else
tracks	equ	76		;96tpi drives
	endif
	else
ddpspt	equ	8		;eight inch
tracks	equ	76
	endif

dpblen	equ	15		;length of a DPB
;
;	floppy disk hardware parameter offsets
;
density	equ	0		;0=single, 1=single side double D, 2= 2S2D
seekrt	equ	1		;THIS IS OFFSET INTO TABLE, VALUE IN TABLE CAN BE
				;seek rate 0=3ms, 1=6ms, 2=10ms, 3=15ms
				;these times double for minifloppies
pspt	equ	2		;physical sectors per track (one side)
drvtrk	equ	3		;track a floppy is at
parmlen equ	4		;length of the parameter block
;
;	miscellaneous equates
;
iobyte	equ	3		;used to select various consoles and printers
cdisk	equ	4		;default disk user number
retries equ	10		;retry count for disk operations
inbfsz	equ	32		;size of input buffer for interrupt input must be power of 2
outbfsz	equ	64		;size of output buffer for interrupt output must be power of 2


	SUBTTL	Hard disk equates 
	page

;***   HDC1001 Disk equates   ***
HOFF	EQU	1		; Number of reserved tracks for loader

TST	MACRO	DN			;physical hard disk defined
	IF	HD&DN
x	defl	1
	else
x	defl	0
	endif
	endm

hddsks	defl	0			;number of physical hard disk drives
hdldrvs	defl	0			;number of logical hard disk drives

hdtst	macro
	tst	%hddsks			;test for physical drives
	iff	x
	exitm
	endif
	.lall
hddsks	defl	hddsks+1
	.xall
	endm		;end hdtst

	hdtst				;calculate number of physical hard disks

	if	hddsks			;set flag for hard disks
hard	equ	true
	else
hard	equ	false
	endif

	.sfcond
	if	hard			;put this stuff in only if needed
	.lfcond

;***   Port equates for HDC1001   ***
HDCBASE	EQU	0E0H		; Base of HDC1001
HDCDATA	EQU	HDCBASE		; Data port
WPC	EQU	HDCBASE+1	; Write precomp port
HDCERR	EQU	WPC		; Error port
SECNT	EQU	HDCBASE+2	; Sector count
SECNO	EQU	HDCBASE+3	; Sector number
CYLLO	EQU	HDCBASE+4	; Cylinder low
CYLHI	EQU	HDCBASE+5	; Cylinder high
SDH	EQU	HDCBASE+6	; Size/Drive/Head
COMND	EQU	HDCBASE+7	; Command register
STATUS	EQU	COMND		; Status register

;***   Command equates for HDC1001   ***
CREST	EQU	10H		; Restore command
CSEEK	EQU	70H		; Seek command
CREAD	EQU	20H		; Read sector command
CWRITE	EQU	30H		; Write command
CFORM	EQU	50H		; Format track

inter	equ	8		;hard disk sector interleave factor
secs	equ	16		;Physical sectors per track per head
hstsiz	equ	512		;size of a hard disk physical sector
hdstcnt	equ	hstsiz/128	;cp/m sectors per physical sector
blksiz	equ	4096		;cp/m block size
cpmspt	equ	hdstcnt*secs	;cp/m sectors per track per head
cpmscbk	equ	blksiz/128	;cp/m sectors per cp/m block
;
dpbg	macro	dn,secs,bls,blm,ext,dks,dir,al0,al1,cks,off,phys
	.lall
dpb&dn:	dw	secs			;sec per track
	db	bls			;block shift
	db	blm			;block mask
	db	ext			;extnt mask
	dw	dks			;disk size-1
	dw	dir			;directory max
	db	al0			;alloc0
	db	al1			;alloc1
	dw	cks			;check size
	dw	off			;offset
	db	phys			;physical disk drive
	.xall
	endm

hdscg	macro	dn,mxcl,mxhd,stprt
	.lall
hdesc&dn:
	db	hdcbase			;base i/o port address
	db	dn			;physical unit no.
	db	inter			;hardware interleave
	db	secs			;sectors per track
	dw	mxcl			;last cylinder
	db	mxhd			;last head
	db	hstsiz/128		;sector size/128
	db	stprt			;step rate
	.xall
	endm

dsktyp	macro	dn,typ
	.lall
	.sfcond
	if	typ eq ST503 
hpb&dn	macro	no
	dw	-1,hdesc&dn	
als&no	defl	004Ch			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,128,5,31,1,607,511,240,0,0,1,%dn
	hdscg	%dn,152,1,3
	endm
hddr&dn	defl	1
	endif	

	if	typ eq ST506
hpb&dn	macro	no
	dw	-1,hdesc&dn	
als&no	defl	0098h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,1215,511,240,0,0,1,%dn
	hdscg	%dn,152,3,3
	endm
hddr&dn	defl	1
	endif	

	if	typ eq TM601S
hpb&dn	macro	no
	dw	-1,hdesc&dn	
als&no	defl	004Ch			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,128,5,31,1,607,511,240,0,0,1,%dn
	hdsc	%dn,152,1,3
	endm
hddr&dn	defl	1
	endif	

	if	typ eq TM602S
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0098h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,1215,511,240,0,0,1,%dn
	hdsc	%dn,152,3,3
	endm
hddr&dn	defl	1
	endif	

	if	typ eq TM603S
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	00E4h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,1823,1023,255,0,0,1,%dn
	hdscg	%dn,152,5,3
	endm
hddr&dn	defl	1
	endif

	if	typ eq TM603SE
hdpb603E0&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,2047,1023,255,0,0,1,%dn
	hdscg	%dn,229,5,3
	endm

hdpb603E1&dn	macro	no
als&no	defl	00FFh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,699,511,240,0,0,172,%dn
	endm

hpb&dn	macro	no
	local	x
x	defl	no
	hdpb603E0&dn	%x
x	defl	x+1
	hdpb603E1&dn	%x
	endm
hddr&dn	defl	2
	endif

	if	typ eq TM501
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0099h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,128,5,31,1,1219,511,240,0,0,1,%dn
	hdscg	%dn,305,1,3
	endm
hddr&dn	defl	1
	endif

	if	typ eq TM502
hdpb5020&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,2047,1023,255,0,0,1,%dn
	hdscg	%dn,305,3,3
	endm

hdpb5021&dn	macro	no
als&no	defl	0031H			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,391,511,240,0,0,257,%dn
	endm

hpb&dn	macro	no
	local	x
x	defl	no
	hdpb5020&dn	%x
x	defl	x+1
	hdpb5021&dn	%x
	endm
hddr&dn	defl	2
	endif

	if	typ eq TM503
hdpb5030&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,2047,1023,255,0,0,1,%dn
	hdscg	%dn,305,5,3
	endm

hdpb5031&dn	macro	no
als&no	defl	00CAH			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,1611,1023,255,0,0,172,%dn
	endm

hpb&dn	macro	no
	local	x
x	defl	no
	hdpb5030&dn	%x
x	defl	x+1
	hdpb5031&dn	%x
	endm
hddr&dn	defl	2
	endif

	if	typ eq SA602
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0050h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,128,5,31,1,635,511,240,0,0,1,%dn
	hdscg	%dn,159,1,3
	endm
hddr&dn	defl	1
	endif

	if	typ eq SA604
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	009Fh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,1271,511,240,0,0,1,%dn
	hdsc	%dn,159,3,3
	endm
hddr&dn	defl	1
	endif

	if	typ eq SA606
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	00EFh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,1907,1023,255,0,0,1,%dn
	hdscg	%dn,159,5,3
	endm
hddr&dn	defl	1
	endif

	if	typ eq SA1002
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0080h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,128,5,31,1,1019,511,240,0,0,1,%dn
	hdscg	%dn,255,1,0
	endm
hddr&dn	defl	1
	endif

	if	typ eq SA1004
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	00FFh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,2039,1023,255,0,0,1,%dn
	hdscg	%dn,255,3,0
	endm
hddr&dn	defl	1
	endif

	if	typ eq Q2010
hpb&dî	macrï	no
	dw	-1,hdesc&dn
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,128,5,31,1,2043,1023,255,0,0,1,%dn
	hdscg	%dn,511,1,0
	endm
hddr&dn	defl	1
	endif

	if	typ eq Q2020
hdpb20&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,2047,1023,255,0,0,1,%dn
	hdscg	%dn,511,3,0
	endm

hdpb21&dn	macro	no
als&no	defl	00FFh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,2039,1023,255,0,0,257,%dn
	endm

hpb&dn	macro	no
	local	x
x	defl	no
	hdpb20&dn	%x
x	defl	x+1
	hdpb21&dn	%x
	endm
hddr&dn	defl	2
	endif

	if	typ eq Q2030
hdpb30&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,2047,1023,255,0,0,1,%dn
	hdscg	%dn,511,5,0
	endm

hdpb31&dn	macro	no
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,2047,1023,255,0,0,172,%dn
	endm

hdpb32&dn	macro	no
als&no	defl	00FEh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,384,5,31,1,2031,1023,255,0,0,343,%dn
	endm

hpb&dn	macro	no
	local	x
x	defl	no
	hdpb30&dn	%x
x	defl	x+1
	hdpb31&dn	%x
x	defl	x+1
	hdpb32&dn	%x
	endm
hddr&dn	defl	3
	endif

	if	typ eq Q2040
hdpb40&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,512,5,31,1,2047,1023,255,0,0,1,%dn
	hdscg	%dn,511,7,0
	endm

hdpb41&dn	macro	no
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,512,5,31,1,2047,1023,255,0,0,129,%dn
	endm

hdpb42&dn	macro	no
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,512,5,31,1,2047,1023,255,0,0,257,%dn
	endm

hdpb43&dn	macro	no
als&no	defl	00FEh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,512,5,31,1,2031,1023,255,0,0,385,%dn
	endm

hdpb4021&dn	macro	no
als&no	defl	00DFh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,1783,1023,255,0,0,257,%dn
	endm

hpb&dn	macro	no
	local	x
x	defl	no
	hdpb40&dn	%x
x	defl	x+1
	hdpb41&dn	%x
x	defl	x+1
	hdpb42&dn	%x
x	defl	x+1
	hdpb43&dn	%x
	endm
hddr&dn	defl	4
	endif

	if	typ eq M4010
hpb&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	00F0h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,128,5,31,1,1915,1023,255,0,0,1,%dn
	hdscg	%dn,479,1,0
	endm
hddr&dn	defl	1
	endif

	if	typ eq M4020
hdpb4020&dn	macro	no
	dw	-1,hdesc&dn
als&no	defl	0100h			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,2047,1023,255,0,0,1,%dn
	hdscg	%dn,480,3,0
	endm

hdpb4021&dn	macro	no
als&no	defl	00DFh			;size of allocation vector
css&no	defl	0			;number of checksum elements
	dpbg	%no,256,5,31,1,1783,1023,255,0,0,257,%dn
	endm

hpb&dn	macro	no
	local	x
x	defl	no
	hdpb4020&dn	%x
x	defl	x+1
	hdpb4021&dn	%x
	endm
hddr&dn	defl	2
	endif

hdldrvs	defl	hdldrvs+hddr&dn
	.lfcond
	.xall
	endm

x	defl	0
	rept	hddsks
	dsktyp	%x,hd%x			;define hard disk parameters
x	defl	x+1
	endm

;
;
dskhdr	macro	dn
;	define a single disk header list
	.lall
hdph&dn:
	dw	0000h,0000h		;translate table
	dw	0000h,0000h		;scratch area
	dw	dirbuf,dpb&dn		;dir buff,parm block
	dw	0000h,0000h		;check, alloc vectors
	.xall
	endm
;
hddisks	macro	nd
;	define nd disks
ndisks	defl	nd			;for later reference
dpbase	equ	$			;base of disk parameter blocks
;	generate the nd elements
dsknxt	defl	nmbfpy
	rept	nd
	dskhdr	%dsknxt
dsknxt	defl	dsknxt+1
	endm
	endm
;
lgdrvs	defl	0
;
hdpbs	macro	dn,lgno
	hpb&dn	lgno
lgdrvs	defl	hddr&dn
	endm
;
hddpbs	macro	times			;define hard disk parameter blocks
	local	x,y
x	defl	0
y	defl	nmbfpy
	rept	times
	hdpbs	%x,%y			;define dpb's for this hd drive
	endm
x	defl	x+1			;bump counters
y	defl	y+lgdrvs
	endm
;
ddb	macro	data,comm
;	define a db statement
	db	data			comm
	endm
;
ddw	macro	data,comm
;	define a dw statement
	dw	data			comm
	endm
;
defds	macro	lab,space
lab:	ds	space
	endm
;
lds	macro	lb,dn,val
size	defl	val&dn
	defds	lb&dn,%size
	endm
;
;
logdsk	defl	nmbfpy

	endif		;hard disk definitions
	.lfcond

fdskhdr	macro	dn
	.lall
fdph&dn:
	dw	trans,0,0,0
	dw	dirbuf,fdpbase
	dw	0000h,0000h
	.xall
	endm
fdisks	macro
x	defl	0
	rept	nmbfpy
	fdskhdr	%x
x	defl	x+1
	endm
	endm

dwdsk	macro	drvr,lgdsk
	dw	drvr+lgdsk
	endm

DSKTBL	MACRO				;DEFINES DISK ASSIGNMENT TABLE

x	defl	0
	.lall
drvtbl	equ	$+1
	.xall

	if	fpyfrst	
	dw	fpy

	rept	nmbfpy-1
	dwdsk	fpy,%x
x	defl	x+1
	endm		;rept

y	defl	0

	rept	hdldrvs
	dwdsk	hdc,%x

	iff	y		;if first time thru
x	defl	0		;reset x for hard disk logical drives starting at 0
y	defl	y+1
	else
x	defl	x+1
	endif
	endm		;rept

	else		;fpyfrst

	dw	hdc

	rept	hdldrvs-1
	dwdsk	hdc,%x
x	defl	x+1
	endm		;rept

y	defl	0

	rept	nmbfpy
	dwdsk	fpy,%x

	iff	y		;if first time thru
x	defl	0		;reset x for hard disk logical drives starting at 0
y	defl	y+1
	else
x	defl	x+1
	endif
	endm		;rept
	endif

	ddb	%x,<;last logical drive>

	rept	16-nmbfpy-hdldrvs
	dw	0
	endm		;rept
	endm		;dsktbl

	SUBTTL	BIOS ENTRY AND PUBLIC TABLES
	page
;
;	BIOS jump table
start::	ret				;no cold boot
	dw	0
	ret				;no warm boot
	dw	0
	jp	pserin
	jp	serin
	jp	serout
	ret				;no list
	dw	0
	ret				;no punch
	dw	0
	ret				;no reader
	dw	0
	jp	home
	jp	seldsk
	jp	settrk
	jp	setsec
	jp	setdma
	jp	read
	ret				;no write
	dw	0
	ret				;no list status
	dw	0
	jp	sectran

	SUBTTL	Console drivers
	page
;
;	Console drivers
;	All have entry A=driver number, other parameters per CP/M
;	A=0 serial port 0; A=1 serial port 1
	
pserin::				;poll serial in-return A=0ff if char ready, else 0
	add	A,A
	inc	A			;A=command port
	ld	C,A
	in	A,(C)
	and	1
	ret	z			;no character waiting
	ld	A,0ffh
	ret

serin::
	ld	B,A
	call	pserin
	ld	A,B
	jr	z,serin			;loop until character received
	add	A,A
	ld	C,A
	in	A,(C)
	and	7fh			;mask high order bit
	ret

serout::
	ld	B,C	;character to output
	add	A,A
	inc	A
	ld	C,A
serst::	in	A,(C)
	and	4
	jr	z,serst
	dec	C
	out	(C),B
	ret

;	miscellaneous character i/o routines
pmsg::					;equivalent to BDOS function 9 (print)
	ld	A,(DE)
	cp	'$'
	ret	z
	ld	C,A
	inc	DE
	push	DE
	xor	A
	call	serout
	pop	DE
	jr	pmsg

phex::					;print A in hex
	push	AF
	rra
	rra
	rra
	rra
	call	hex1
	pop	AF
hex1::	and	0fh
	add	A,90h
	daa
	adc	A,40h
	daa
	ld	C,A
	xor	A
	jp	serout
;
;
setdma::
	ld	(iodma),BC	;shared among all drivers
	ret

;
;	Sectran input::  Logical sector in BC, translate table in DE
;			no translation if DE=0
;
;			Returns physical sector in HL
;			Note:: only used in single density
	
sectran::
	ld	A,D
	or	E
	ld	L,C
	ld	H,B
	ret	z		;no sector translation
	ex	DE,HL
	add	HL,BC
	ld	L,(HL)
	ld	H,0
	ret

	SUBTTL	Floppy disk driver module
	page
;
;	Floppy disk drive driver module
;
	.sfcond
	iff	hard			;if not hard disk
	.lfcond

dskparm::	;disk hardware parameter block
		;one block for each drive
	rept	nmbfpy

	if	(mini and not special)
	db	1	;single sided double density
	else
	db	0	;density - 0=single D; 1=1 side, Double D; 2= 2S 2D
	endif

	db	seekrate ;seek rate - 0=3ms, 1=6ms, 2=10ms, 3=15ms

	if	(mini and not special)
	db	ddpspt
	else
	db	26	;physical sectors per track - 26 in SD, ddpspt in DD
	endif

	db	0	;track drive currently set at
	endm
page
;
;	CP/M disk tables

fDPHbase::
	fdisks			; defind disk parameter headers for floppys
	page
;
;	DPB's for the three formats of disk::
;
;	8" Single sided, single density
;	5" Single sided, double density
;	5" Double sided, double density
;
fdpbase::
sssddpb::			;single density (1K block)
	dw	26		;sectors per track
	db	3		;block shift (log2[block size/128])
	db	7		;block mask  ([block size/128]-1)
	db	0		;extent mask
	dw	242		;highest block on disk (numbered from 0)
	dw	63		;directory entries-1
	db	0c0h		;alloc0 -first two bits for two blocks for Dir
	db	0		;alloc1
	dw	16		;checked directories
	dw	2		;track offset (system tracks)
page
ssdddpb::			;single sided double density
	dw	8*ddpspt	;128 byte sectors per track
	db	4
	db	0fh
	db	0
	dw	(tracks*ddpspt/2)-1	
				;each of 76 tracks has ddpspt/2 2K blocks
if	mini
	dw	63
	db	80h
else
	dw	127
	db	0c0h
endif

	db	0
	dw	32
	dw	1

dsdddpb::			;double sided double density
	dw	16*ddpspt	;one track consists of both sides
	db	4
	db	0fh
	db	0
	dw	(tracks*ddpspt)-1 	;each of 76 tracks has ddpspt 2K blocks

if	mini
	dw	127
	db	0c0h
else
	dw	255
	db	0f0h
endif

	db	0
	dw	32
	dw	1
page
trans::				;single density translate table
	db	1,7,13,19,25,5,11,17,23,3,9,15,21	;sectors 1-13
	db	2,8,14,20,26,6,12,18,24,4,10,16,22	;secotrs 14-16

home::
	ld	C,0

settrk::
	ld	A,C
	ld	(iotrk),A
	ret

setsec:: ld	A,C
	ld	(iosec),A
	ret

page
;
;	Fseldsk selects the physical floppy in A (0-3)
;	B=0 if last disk selected was a different floppy
;	C=logical disk the floppy corresponds to

seldsk::
	ld	D,0			;physcial floppy
	ld	E,C			;save logical disk
	call	getden			;will set density byte if successful
	or	A
	jr	nz,fbadsel		;couldn't get density
					;all physical operations OK here

	ld	(hwptr),IX		;store for later use
	ld	A,(IX+density)
	inc	A			;make 1-3
	ld	B,A
	ld	HL,fdpbase-dpblen
	ld	DE,dpblen
fgetdpb:: add	HL,DE
	djnz	fgetdpb
					;HL=DPB address
	ld	C,L
	ld	B,H
	ld	HL,fdphbase
	ld	A,(IX+density)
	or	A
	jr	z,setran		;single density,set translate vector
	xor	A
	ld	(HL),A
	inc	HL
	ld	(HL),A
	jr	putdpb
setran::
	ld	DE,trans		;single density translate table
	ld	(HL),E
	inc	HL
	ld	(HL),D
putdpb:: ld	DE,9			;offset of DPB in DPH
	add	HL,DE
	ld	(HL),C
	inc	HL
	ld	(HL),B
	dec	HL
	dec	HL
	sbc	HL,DE			;restore DPH (carry reset by or A)
	ret

fbadsel::ld	HL,0
	ret				;return error
	page
;
;	Seldrv selects the drive , head from (head)
;	(bit 0 set for head1), and density from (IX+density)
;	it assembles the correct byte and outputs to wait
;	and updates the track register with the most recent information

seldrv::
	ld	A,(IX+density)
	or	A
	jr	z,setdens
	ld	A,00001000b	;set double density bit
	ld	B,A
	ld	A,(head)
	rlca
	rlca			;move head bit to bit 2
	or	B
setdens:: ld	B,A
	out	(wait),A
	ld	A,(IX+drvtrk)	;get track from parameter table
				;this may be first physical i/o
	out	(trk),A
	ret
page
;
;	Seek attempts to step the R/W head to the track in (iotrk)
;
seek::
	ld	A,retries
	ld	(retryc),A
seek2::	ld	A,(iotrk)
	ld	C,A		;track stays in C
	in	A,(trk)
	sub	C
	ret	z		;already there

	ld	A,C
	out	(data),A
	ld	A,(IX+seekrt)	;seek rate mask
	or	1ch		;seek with verify
	di
	out	(cmd),A
	in	A,(wait)
	ei
	rla
	jr	c,seekerr	;no INTRQ from FDC

	in	A,(cmd)
	and	10011001b	;seek error, CRC error, or incomplete
	jr	nz,seekerr

				;seek successful
	ld	(IX+drvtrk),C
	ret

seekerr:: ld	E,1ch		;seek command
	call	diskerror
	jr	seek2
page
;
;	Read reads the sector from the selected disk
;	In double density, the sector may already be in the host buffer
;
read::
	ld	IX,(hwptr)		;restore parameter pointer
	ld	A,(IX+density)		;density byte
	or	A
	jr	z,rdsngl		;singl density

	call	inbuf
	jr	c,rddbl			;sector not in buffer
;					sector is in buffer
movrd::	call	mkbufad			;HL=start of sector in buffer
	ldir
	ret				;transfer done

rddbl::	call	sidesec
	call	readprep
	or	A
	ret	nz
	jr	movrd



rdsngl::
	ld	A,(iosec)
	ld	(psec),A		;physical sector same as CP/M sector
					;in single density

readprep:: ld	A,0A2h			;second byte of INI instruction
	ld	(iotran+1),A		;patch rdwrite routine
	ld	A,08ch			;sector read command
	ld	(oper),A
page
strtsel:: call	seldrv			;physically select drive and head
	call	seek			;step to correct track

;
;	diskio actually reads or writes the necessary sector
;	it assumes that the head has already settled on the correct track
;	(and that the head has been selected on the correct side!)
;	and that the bytes in rdwrite for R/W and sector size have been filled

diskio::
	ld	A,retries
	ld	(retryc),A	

iotry::	ld	A,0d0h			;force interrupt no conditions
	out	(cmd),A
	ld	A,(oper)
	ld	B,A
	ld	C,data			;prepare for indirect I/O instruction
	ex	(SP),HL			;waste some time
	ex	(SP),HL
	ex	(SP),HL
	ex	(SP),HL
	di			;no interrupts from here to end of transfer
	in	A,(cmd)
	and	20h			;bit 5=head loaded
	rrca
	rrca
	rrca				;move bit 5 to bit 2
	cpl
	and	B			
			;	the purpose of these manipulations has been
			;	to set bit 2 of the FDC command if the head
			;	isn't settled.  Bit 2 will give a 15 ms delay
	ld	E,A
	ld	A,(IX+density)
	or	A
	ld	D,1		;one sector i/o transfer for single denisty
	jr	z,dmasingl	;use the CP/M DMA buffer in single density
	ld	HL,hstbuf	;use host buffer for double density operations
	ld	D,hstcnt	;number of 128 byte units to transfer
	jr	strtio
dmasingl::
	ld	HL,(iodma)
strtio::	ld	A,(psec)
	out	(sec),A		;set physical sector
	ld	A,E
	out	(cmd),A		;start read/write operation
	call	rdwrite		;do the actual i/o
	in	A,(cmd)
	ei			;now ok to interrupt-status is saved
	ld	E,A		;save status
	or	B		;B returned from rdwrite is lost bytes count
	ret	z		;if status OK and no lost bytes
	
	call	diskerror
	call	seek
	or	A
	jr	z,iotry		;if nonzero then hopeless seek error
	ret
;
;	rdwrite does the actual transfer to/from the FDC
;	HL set to DMA address on entry, D=number of 128 byte units to transfer
;	transfer direction has been set by poking INI or OUTI instruction

rdwrite::
	ld	B,128			;bytes in one CP/M sector
loop::	in	A,(wait)
	or	A
	ret	p			;no more DRQ
iotran::	ini				;start with read
			;the second byte of this instruction is patched to
			;be either INI or OUTI depending on need
	jr	nz,loop
	dec	D
	jr	nz,rdwrite
	jr	loop			;sector done, wait for INTRQ from fdc
	page
;
;	disk error will eventually have all kinds of nice messages
;
diskerror::
	ld	A,(retryc)
	dec	A
	jr	nz,restore		;more retries to attempt
	ld	A,E
	cp	1ch			;was it a seek error?
	jr	z,pseekerr
	cp	0ach			;writing?
	jr	z,pwriterr
	ld	DE,rderr
	jr	perrtyp
pwriterr:: ld	DE,wrterr
	jr	perrtyp
pseekerr:: ld	DE,skerr
perrtyp:: call	pmsg
	ld	DE,trkerr
	call	pmsg
	ld	A,(iotrk)
	call	phex
	ld	DE,secerr
	call	pmsg
	ld	A,(psec)
	call	phex
	ld	DE,siderr
	call	pmsg
	ld	A,(head)
	call	phex
pdrv:: 	ld	DE,drverr
	call	pmsg
	ld	DE,crlf
	call	pmsg
	ld	A,255
	ret
	page
;
;	Restore is called from a disk operation with A=retries left
;
restore::
	ld	(retryc),A
	in	A,(cmd)
	and	00010000b		;bit 4=record not found
	ret	z			;try again if record was found but
					;read/written with error
resto1::					;restore to track 0 and seek again
	ld	A,(IX+seekrt)		;get seek rate mask
	or	00001100b		;head load, restore, verify track 0
	out	(cmd),A

tk0wait::
	in 	A,(cmd)
	and	00000100b		;at track 0
	jr	z,tk0wait
	xor	A
	out	(trk),A			;back at track 0
	ld	(IX+drvtrk),A		;update track table
	ret
page
;
;	sidesec is the read/write preparation for double density
;	sidesec computes the correct physical sector and side
;
sidesec::
	ld	A,(iosec)
	and	not(hstcnt-1)		;computer first CP/M sector in block
	ld	(blksec),A

sideflsh::				;called to set up for a flush
	rept	hstshft
	rrca
	endm
					;A=physical sector number, but it may
					;be on the second side
	ld	B,(IX+pspt)		
	cp	B
	ld	C,0
	jr	c,side0			
	sub	B
	inc	C
side0::	inc	A
	ld	(psec),A		;physical sector on one side
	ld	A,C
	ld	(head),A		;set head control byte
	ret
page
;
;	inbuf returns carry flag set if sector not in buffer
;	also returns (iosec) in D
;	if sector is in buffer, returns offset (0 - hstcnt-1) in A
;
inbuf::	ld	A,(iosec)
	ld	D,A
	ld	A,(bufvalid)		;0 if contains valid data, else 255
	rra
	ret	c
inbuf2:: ld	HL,(iodrvtrk)		;check for 2nd sector 
					;of unallocated block 
	ld	BC,(blkdrvtrk)
	sbc	HL,BC			;same drive and track
 	jr	z,rttrk
	scf
	ret				;not a match
rttrk::	ld	A,(blksec)
	ld	B,A
	ld	A,D
	sub	B
	ret	C			;sector lower # than buffer
	cp	hstcnt			;carry set if in buffer
	ccf
	ret

;	stores drive, track, sector of contents of buffer for use by flush
;	also saves hardware pointer and sets buffer valid flag
;	returns HL=start of sector in buffer, DE=DMA address, BC=128, A=0

mkbufad:: ld	(blkptr),IX
	ld	HL,(iodrvtrk)
	ld	(blkdrvtrk),HL
	ld	A,(iosec)
	ld	B,A
	and	not(hstcnt-1)
	ld	(blksec),A
	ld	A,B
	and	hstcnt-1 
	ld	B,A			;B=relative sector in buffer
	inc	B
	ld	HL,hstbuf-128
	ld	DE,128
shft2::	add	HL,DE
	djnz	shft2
	ld	BC,128			;make ready for sector LDIR
	ld	DE,(iodma)
	xor	A
	ld	(bufvalid),A
	ret
	page
;
;	returns IX=start of DHPB (disk hardware parameter block) for
;	the drive in A (0-3)  
;	uses B,DE  also, returns D=0

getparm::
	ld	B,A
	inc	B
	ld	IX,dskparm-parmlen	;hardware parameter block
	ld	DE,parmlen
shft1::	add	IX,DE
	djnz	shft1	
	ret

page
;
;	Getden attempts to find the density of the disk in drive (D)
;	by trying to read the current track address in both densities
;	If the attempt is successful, Getden will update the
;	dens, pspt, and drvtrk fields of the paramter table
;	If E (logical disk) is zero, then getden assumes the density hasn't
;	changed (if it has, then we can't do a warm boot-table is wrong

getden::
	ld	A,0d0h			;reset FDC
	out	(cmd),A
	ld	A,D
	and	7fh
	call	getparm
	ld	A,(7fh)			;code byte for disk type
	OR	A
	jr	z,codeok		;some SD disks have old loaders here
	sub	0e5h			;code for a normal single density disk
	cp	3
	jr	c,codeok
	ld	DE,badcode		;not our code byte
	call	pmsg
	call	pdrv
	ld	A,255
	ret
codeok:: ld	(IX+density),A
	or	A
	jr	z,snglspt
	ld	A,ddpspt		;physical sectors on one side of DD
	jr	putpspt
snglspt:: ld	A,26d			;single density physical sectors
putpspt:: ld	(IX+pspt),A	
	xor	A
	ret				;no errors

logdin::call	getparm
	ld	A,(IX+density)
	jr	codeok			; drive can't change density

	else			;iff hard
	SUBTTL	Hard disk drivers
page
	.lfcond
;
;	Hard disk drive driver module
;
;
;	CP/M Hard disk tables
;

hDPHbase::
	hddisks	hdldrvs			;set up disk parameter headers
;
;	DPB's for HARD DISKS
;
;
hdpbase	equ	$+4
	hddpbs	hddsks			;set up disk parameter blocks

page

home::
	ld	BC,0		;force track 0

settrk::
	ld	(hdiotrk),BC	;save track number
	ret

setsec::
	ld	(hdiosec),BC	;save sector number
	ret
;
;	Hseldsk selects the hard disk

seldsk::
	ld	HL,hdphbase		;add in base address
	ret				; and go
;
;	Seldrv selects the drive from (curhdsk), head from (hhead)
;	it assembles the correct byte and outputs it
;	and updates the track register with the most recent information

hseldrv::
	ld	A,(hhead)			;get head
	or	20h			;set sector size to 512 bytes
	out	(sdh),a			;send to controller
	ret
page
;
;	Seek sets head to the track in (hdiotrk)
;	 and sector to (hpsec), sector count to one
;
hseek::	ld	a,(hdiotrk)		;send low order byte of track
	out	(cyllo),a
	ld	a,(hdiotrk+1)		;send high byte
	out	(cylhi),a
	ld	A,(hpsec)		;send physical sector
	out	(secno),A
	ld	A,1			;set sector count
	out	(secnt),A
	ret
page
;
;	Read reads the sector from the selected disk
;	it handles any necessary buffering
;
read::	call	hinbuf			;is it in the buffer
	jr	c,hrd			;sector not in buffer

;					sector is in buffer
hmvrd::	call	hmkbfad			;HL=start of sector in buffer
	ldir
	ret				;transfer done

hrd::	call	hsidselc
	call	hrdprep
	or	A
	ret	nz
	jr	hmvrd
;
;	read preperation
;
hrdprep::
	call	hseldrv			;physically select drive and head
	call	hseek			;step to correct track

;
;	this actually reads the necessary sector
;	it assumes that the head has already settled on the correct track
;	(and that the proper head has been selected)

	ld	HL,hstbuf		;point to buffer
	ld	BC,hdcdata		;count and port
	di				;protect transfer
	ld	A,cread			;send read command
	out	(comnd),A
hrdw::	in	A,(status)		;done yet
	and	A
	jp	m,hrdw			;if not wait
	inir				;256 bytes twice
	inir
	ei
	in	A,(status)
	and	1			;any errors
	ret	z			;return if not
;
	page
;
;	hard disk error message processor
;
;	This routine gives the user a detailed error report
;
herrors::
	push	AF			;save error indication
	ld	DE,herrst
	CALL	pmsg			; First the error code
	IN	A,(HDCERR)
	CALL	phex
	ld	DE,errhd
	CALL	pmsg			; then the head
	IN	A,(SDH)
	push	AF			;save drive no
	AND	7
	CALL	hex1			; Print single digit
	ld	DE,errcyl
	CALL	pmsg			; the cylinder
	IN	A,(CYLHI)		; Report CYLHI first
	CALL	phex
	IN	A,(CYLLO)		; then CYLLO
	CALL	phex
	ld	DE,errsec
	CALL	pmsg			; and finally the sector
	IN	A,(SECNO)
	CALL	phex
	ld	DE,errdr		;send drive mess
	call	pmsg
	pop	AF
	rlca				;get drive
	rlca
	rlca
	and	3
	call	hex1
	ld	A,crest			;restore drive
	out	(comnd),A
herrlp::
	in	A,(status)
	rlca
	jr	c,herrlp		;wait until done
	poð	AF
	RET	
	page
;
;	hsidselc is the read/write preparation for hard disk
;	hsidselc computes the correct physical sector and side
;
hsidselc::
	ld	HL,(hdiosec)
	ld	E,L			;save L
	ld	A,L
	and	not(31)			;compute first cp/m sector in buffer
	ld	L,A
	ld	(hblksec),HL		;save it
	ld	L,E			;restore sector to HL

hflsdsc::				;called to set up for a flush
	or	a			;clear carry
	ld	C,-1			;set up head count
	ld	DE,secs*4		;set up number cpm sectors per head
sdsclp:	inc	C			;increment head count
	sbc	HL,DE			;subtract out one heads worth of sectors
	jp	p,sdsclp		;if not negitive do more
	add	HL,DE			;restore sector number to HL
	ld	A,L
	srl	A			;find physical sector
	srl	A
	ld	(hpsec),A
	ld	A,C
	ld	(hhead),A		;set head control byte
	ret
page
;
;	hinbuf returns carry flag set if sector not in buffer
;	if sector is in buffer, returns offset (0 - hdstcnt-1) in A
;
hinbuf::
	ld	A,(bufvalid)		;0 if contains valid data, else 255
	rra
	ret	c

hinbuf2::
	ld	A,(hiodrvtrk)		;check for right drive
	ld	B,A
	ld	A,(hblkdrvtrk)
	sub	B
	jr	z,rthdd			;skip if right drive
	scf
	ret				;wrong drive return with carry set
rthdd::	ld	HL,(hiodrvtrk+1)		;check for right track
	ld	BC,(hblkdrvtrk+1)
	sbc	HL,BC			;same drive and track
	scf
	ret	nz			;not a match
	ld	DE,(hblksec)
	ld	HL,(hdiosec)
	ld	A,D			;high bytes =
	cp	H
	scf				;set failure flag
	ret	nz			;exit if not equal
	ccf				;clear carry
	sbc	HL,DE
	ret	C			;sector lower # than buffer
	ld	A,L
	cp	hdstcnt			;carry set if in buffer
	ccf
	ret
;
;	stores drive, track, sector of contents of buffer for use by flush
;	also sets buffer valid flag
;	returns HL=start of sector in buffer, DE=DMA address, BC=128, A=0
;
hmkbfad::
	ld	A,(hiodrvtrk)
	ld	(hblkdrvtrk),a
	ld	HL,(hiodrvtrk+1)
	ld	(hblkdrvtrk+1),HL
	ld	HL,(hdiosec)
	ld	B,L
	ld	A,L
	and	not(hdstcnt-1)
	ld	L,A
	ld	(hblksec),HL
	ld	A,B
	and	hdstcnt-1 
	ld	B,A			;B=relative sector in buffer
	inc	B
	ld	HL,hstbuf-128
	ld	DE,128
hshft2::
	add	HL,DE
	djnz	hshft2
	ld	BC,128			;make ready for sector LDIR
	ld	DE,(iodma)
	xor	A
	ld	(bufvalid),A
	ret
	endif

	SUBTTL	Floppy disk storage
page
;
;	Floppy disk driver storage
;
bufvalid::
	db	0ffh		;buffer contains valid data for (blksec)
				;0 = valid data
iodma::	ds	2		;dma storage

	.sfcond
	iff	hard			;if not hard
	.lfcond

iodrvtrk::
curfpy::
	db	0		;current selected physical floppy drive
iotrk::	ds	1		;current track for current disk

blkdrvtrk::
	ds	2		;drive and track for deblocking buffer
iosec::	ds	1		;current logical sector for DD, physical for SD
blksec::
	ds	1		;first logical sector in current host
blk2sec::
	ds	1		;8th CP/M sector in an unallocated 2K block
psec::	ds	1		;current physical sector
wrtpend::
	db	0		;write pending from buffer
retryc::
	db	0		;number of retries left
newfpy::
	db	0		;new floppy to be selected
head::	db	0		;head control = 0 or 1
oper::	db	0		;operation (read/write) to be performed next
hwptr::	dw	dskparm		;storage for pointer to current hw parameters
blkptr::
	dw	dskparm		;pointer to paramters for block drive

	SUBTTL	Hard disk storage
page
;
;	Hard disk driver storage
;
	else
	.lfcond

hiodrvtrk::
curhdsk::
	db	0		;current selected physical hard disk drive
hdiotrk::
	ds	2		;current track for current disk

hblkdrvtrk::
	ds	3		;drive and track for deblocking buffer
hdiosec::
	ds	2		;current logical sector
hblksec::
	dw	0		;first logical sector in host buffer
hunalsec::
	dw	0		;first logical sector in current host unallocated block
unalcv::
	db	0		;unallocated block vector
hpsec::	ds	1		;current physical sector
hwrtpnd::
	db	0		;write pending from buffer
hhead::	db	0		;head control
	endif

	SUBTTL	Error messages
page
	.sfcond
	iff	hard
	.lfcond
;
;	Floppy error messages
;
badcode::
	db	'Can''t recognize density of disk in$'
rderr::	db	'Read$'
wrterr::
	db	'Write$'
skerr::	db	'Seek$'
trkerr::
	db	' error on track $'
secerr::
	db	'  sector $'
siderr::
	db	'  side $'
drverr::
	db	'  drive $'
crlf::	db	0dh,0ah,'$'
	page
;
;	Hard disk error messages
;
	else
	.lfcond
herrst::
	DB	0dH,0ah,'HD1001 Error $'
errhd::	DB	' on Head $'
errcyl::
	DB	', Cylinder $'
errsec::
	DB	', Sector $'
errdr::	db	', Drive $'
	endif

	SUBTTL	Disk buffers and Cold Boot code
page
;
;	disk buffers
;	These are not part of the floppy driver module as such and
;	should be shared by all disk modules as much as possible

dirbuf::
hstbuf	equ	dirbuf+128		;sector deblocking buffer
;
;
lastadd	equ	$	
	SUBTTL	SYMBOLS
	end