ORG 100H
		.z80



;****************************************************************
;*								*
;*   This program reads the bad map on a Seagate ST-506		*
;*   and prints out the bad areas.  The bad map sector is	*
;*   assumed to be at cylinder 0, head 2, sector 0.		*
;*								*
;****************************************************************






rstchan	equ	50h
drive0	equ	0h
sel	equ	0
stepl	equ	1
steph	equ	2
hdsel	equ	3
dmal	equ	4			;dma data pointer
dmah	equ	5
dmax	equ	6
arg0	equ	7			;command argument pointer
arg1	equ	8
arg2	equ	9
arg3	equ	0ah
cmnd	equ	0bh
status	equ	0ch
stepin	equ	0h			;constant to go to track 152, drive 0
stepout equ	10h			;constant to go to track 0, drive 0
step	equ	06h
attn	equ	55h
maxtrac	equ	09bh			;number of tracks for ST-506
cpm	equ	0			;warm boot
channel	equ	80h
reset	equ	54H

init:	ld	sp,100h			
	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

start: 	ld	ix,channel		;get the channel address
	ld	a,step
	ld	(ix + cmnd),a		;step command
	ld	a,0
	ld	(ix + status),a		;null the status
	ld	(ix + dmal),a		;low byte data dma address
	ld	(ix + dmax),a		;extended data dma address
	ld	(ix + steph),a		;null high step byte
	ld	a,0ffh
	ld	(ix + stepl),a
	ld	a,stepout
	ld	(ix + dmah),a		;high byte of dma address
	ld	(ix + sel),a		;send it home constant
	call	loop			;send it home
	call	nulsek			;clear the step bytes
	ld	(ix + cmd),a		;read command
	ld	(ix + status),a		;null the status byte
	ld	(ix + arg0),a		;cylinder 0
	ld	(ix + arg1),a		
	ld	(ix + arg3),a		;sector 0
	ld	a,02h
	ld	(ix + arg2),a		;head 2
	call	loop			;read it
	

check:	ld	hl,1000h		;beginning of map
	ld	a,0			;normal map entry if no errors
check1:	cp	(hl)			
	call	nz,error
	inc	hl
	bit	6,l			;check for sector end
	jr	nz,check1
	jp	cpm
	

error:	call	crlf
	ld	c,09h
	ld	de,mess0
	push	hl
	call	bdos
	pop     hl
	ld	a,(hl)
	call	number
	inc	hl
	call	crl











nulsek:	xor	a
	ld	(ix + stepl),a
	ld	(ix + steph),a
	ret	



mess0:	db	'Cylinder     ,$'

mess1:  db	'Head         ,$'

mess2:  db	'Sector	      ,$'







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

loop0:	ld	a,(ix + status)
	cp	0ffh
	ret	z
	dec	hl
	ld	a,h
	or	l
	jr	nz,loop0
	dec	c
	jr	nz,loop0 
	jp	cpm

	end