; HDC/DMA head park program
;         Initial coding - 8/1/83 - BJG

	org	100h
		.z80


bdos	equ	05
rstchan	equ	50h
drive0	equ	0
drive1	equ	1	
drive2	equ	2
drive3  equ	3
head0	equ	01CH			;0001 1100
head1	equ	018H			;0001 1000
head2	equ	014H			;0001 0100
head3	equ	010H			;0001 0000
head4	equ	0CH			;0000 1100
head5	equ	08H			;0000 1000
head6	equ	4			;0000 0100
head7	equ	0			;0000 0000
sel	equ	0			;drive byte for seek command
select  equ	3			;drive/head select byte
stepl	equ	1
steph	equ	2
cmnd	equ	0bh
status	equ	0ch
stepin	equ	0fh			;constant to go to maxtrac
stepout equ	10h			;constant to go to track 0
step	equ	06h
sense	equ	05h
attn	equ	55h
maxtrac	equ	306			;number of tracks for m10/m16
cpm	equ	0			;warm boot
channel	equ	cmdchan
stepdeì eqõ     01Eè                    ;steð delaù foò  ST-506
settle  equ     0                       ;head settle for ST-506  
secsiz  equ     7                       ;1024 byte sectors 
reset	equ	54H
arg0    equ      07            		;command arguments  
arg1    equ      08            		;command arguments  
arg2    equ      09            		;command arguments  
arg3    equ      0ah           		;command arguments  
cnsts   equ     04h                     ;load constants cmd
ready	equ	04h



mesage: ld	sp,01000h
	ld	c,25
clear:	push    bc
        call	crlf			;clear the screen
        pop     bc
	dec	c
	jp	nz,clear
Š
; print a signon message

        ld	de,signon		;print signon message
	call	pmsg
	ld 	de,sign1
	call	pmsg
	call	crlf

; set up the DMA channel and reset the controller

init:	ld	b,0
	ld	c,10H
	ld	hl,channel
	ld	(rstchan),hl
	ld	(channel + 0dh),hl	;link field init
	xor	a
	ld	(rstchan + 2),a		;channel address @ 80h
	ld	(channel + 0fh),a	;link field init
	out	(reset),a
loop1:	dec	c			;wait for controller to reset
	jr	nz,loop1



; perform a LOAD CONSTANTS command

init1:  ld      ix,channel
        ld	(ix + sel),a		;zero select byte
	ld	(ix + stepl),a		;zero steps
	ld	(ix + steph),a		;zero steps
	ld      (ix + arg0),a		;zero cyl argument
        ld      (ix + arg2),a  		;zero head settle
	ld	a,01ah			;drive 0 head 0
	ld	(ix + select),a		;turn off step
        ld      a,stepdel    		;3 ms steps
        ld      (ix + arg1),a
        ld      a,secsiz    
        ld      (ix + arg3),a  		;1024 sectors
        ld      a, cnsts		;load constants cmd
        ld      (ix + cmnd),a
        call    loop

; check for drive presence - all four drives

	ld	iy,drv0			;drive pointer
	ld	a,sense
	ld	(ix + cmnd),a		;sense status command
check:	ld	a,0
	ld	(ix + status),a		;null the status
	ld	a,(iy)
	ld	(ix + select),a
	push	af			;save current drive
	call	loop			;kick controller
	bit	2,a			
Š        jp	nz,next			;check for drive ready
	pop	af			;get back current drive
	ld	(iy),a			;save it

check1:	inc	iy
	inc	a			;increment drive
	cp	04		
	jp	nz,check		;loop for 3 drives
	jp	start

; go here if no drive present

next:	ld	a,0ffh
	ld	(iy),a			;flag drive as non-existant
	pop	af
	jp	check1
	
; step all the valid drives to track 0

start:	ld	b,0			;counter
	ld	iy,drv0			;drive table pointer
	ld	a,step
	ld	(ix + cmnd),a		;step command
start1:	ld	a,0
	ld	(ix + status),a		;null the status
	ld	a,0ffh
	ld	(ix + stepl),a
	ld	(ix + steph),a	
	ld	a,(iy)
	cp	0ffh			;check for non existant drive
	jp	z,newone	
	or	stepout
	ld	(ix + sel),a		;send it home constant
	ld	(ix + select),a
	call	loop

; step all the valid drives to maxtrack

goout:	xor	a
	ld	(ix + status),a		;null the status
	ld	a,(ix+sel)		
	and	stepin			;for each drive
	ld	(ix + sel),a		;constant to seek in
	ld	hl,maxtrac		;306d for cmi
	ld	(channel + stepl),hl
	call	loop

newone:	inc	iy
	inc	b
	bit	2,b
	jp	z,start1		;once for each drive
	jp	leave			;warm boot



Š;   Routine kicks controller and waits for status to change
;   from a 0 to some other value... 'A' register contains status
;   value on return. (H & L, C, A registers not preserved)

loop:	out	(attn),a		;kick controller
	ld	hl,0
	ld	c,10h			;1 minute to respond

loop0:	ld	a,(ix + status)
	cp	00h
	ret	nz
	dec	hl
	ld	a,h
	or	l
	jp	nz,loop0
	dec	c
	jp	nz,loop0 
	jp	error

; print string pointed to by D & E

pmsg:	ld	c,09		;bdos print line call
	call	bdos

; print CRLF

crlf:	ld	e,0ah		;CR
	call	cout
	ld	e,0dh		;LF
	
; print character in the E register

cout:	ld	c,02		;bdos print character call
	call	bdos
	ret	

; print a space

space:  ld 	e,20h
	call	cout
	ret

; Controller timeout error

error:	ld	de,errmsg
	call	pmsg
	call	crlf
	jp	cpm

; successful down exit... print logoff and select drive 4

leave:  ld	bc,00h
	ld	iy,drv0
leav1:	ld	a,(iy)
	cp	0ffh		;was it active
Š	jp	nz,incb		;take jump if not
incc:	inc	c
	bit 	2,c
	jp	nz,lmesag
	inc	iy
	jp	leav1
		
incb:	inc	b
	jp	incc

lmesag: push	bc
	call	space		;print a space
	pop	bc
	ld	a,030h		;force ascii "1"
	add	a,b		;get number drives tested
	push	bc
	ld	e,a
	call	cout
	pop	bc
	ld	a,b
	cp	1		;special message for 1 drive
	jp	nz,many
	ld	de,lvmsg1
	jp	cont
many:	ld	de,lvmsg	
cont:	call	pmsg
	ld	de,signof
	call	pmsg
	call	crlf
	call	crlf
	ld	de,advise
	call	pmsg
	call	crlf
	call	crlf


; select drive 4 for power down

	ld	hl,0
	ld	(channel + 1),hl	;null the steps
	ld	a,drive3
	ld	(ix + sel),a
	ld	(ix + select),a		;select last drive
	out	(attn),a		;kick controller


stop:	jp	stop			;loop forever

; display messages

signon:  db	'              Decision 1 Shutdown Program $'
sign1º 	 dâ 	§ No÷ parkinç winchesteò headó iî safå landinç zones... $'
signof:  db	' Your system is now ready to be turned off. $'
errmsg:	 db	' HDC/DMA controller not responding! $'
lvmsg:	 db	'  drives are now ready to be turned off. $'
lvmsg1:	 db	'  drive is now ready to be turned off. $'
advise:	 db	' Remember to backup on floppy and run CHECK.COM periodically!! $'

; local variables
Š
drv0:	 db	0
drv1:	 db	1
drv2:	 db	2
drv3:	 db	3

; DMA command channel on reset

cmdchan equ    $ 


	end