hdorg	equ	120q
	stat	equ	hdorg
	cntrol	equ	hdorg
	data	equ	hdorg+3
	functn	equ	hdorg+2
	commd	equ	hdorg+1
	result	equ	hdorg+1
	trks	equ	200
	bdos	equ	5h	;BDOS entry
	acr	equ	0dh	;carriage return
	alf	equ	0ah	;line feed
	drsel	equ	0fch	;DR 0, HD 0, STEP OUT
	drvrdy	equ	20h	;Drive Ready bit
	cntrl	equ	0dh	;WENBL, MCLK, FRENBL
	clrflt	equ	5h	;Toggle 3bit to clr wrfault
	run	equ	0fh	;cntrl + RUN bit
	wrsect	equ	7h	;WRITE SECTOR COMMAND
	rdsect	equ	3h	;READ SECTOR COMMAND
	opdone	equ	2h	;OP DONE STATUS BIT
	dirbit	equ	8h
	stpbit	equ	4h	;toggle to step
	tkzro	equ	1h	;Track Zero bit
	halt	equ	80h	;Halt bit
	nflt	equ	10h	;Write Fault
	tmout	equ	8h	;Timeout bit
	cmplt	equ	4h	;Complete bit
	xrtry	equ	2h	;Auxilliary status retry bit
	djiost	equ	0e3f9h	;DJ UART STATUS
	djdata	equ	0e3f8h	;DJ DATA
	djdr	equ	4h	;DJ DATA READY WHEN OFF
	wboot	equ	0h	;RESTART
	tstpat	equ	0aah	;Test pattern 10101010
	himem	equ	8h	;High Memory Select & Reset

	ORG	100H
	lxi	d,sgnon
	call	pbuff
	;select drive, head & Mclock, out step direction
setup	mvi	a,drsel
	out	52h
	mvi	a,cntrl		;enable function register
	out	50h
	;toggle write enable to clr write fault
	mvi	a,clrflt
	out	50h
	mvi	a,cntrl
	out	50h
	in	50h	;see if write fault cleared
	ani	nflt
	jnz	ckrdy		;no error
	lxi	d,noclr
	call	pbuff
	jmp	setup
ckrdy	in	50h
	ani	drvrdy
	jz	ckhalt
	lxi	d,ntrdy
	call	pbuff
	jmp	setup
ckhalt	in	50h
	ani	halt
	jnz	setrun
	lxi	d,nothlt
	call	pbuff
	jmp	setup
setrun	mvi	a,run
	out	50h
trk00	in	stat
	ani	tkzro
	jz	stepin
stpout	mvi	a,drsel
	xri	stpbit
	out	functn
	xri	stpbit
	out	functn
	call	delay
	call	ckint
	jmp	trk00
stepin	mvi	a,trks
	mov	c,a
	mvi	a,drsel
	xri	dirbit
	mov	b,a
	out	functn
stepi	mov	a,b
	xri	stpbit
	out	functn
	xri	stpbit
	out	functn
	push	b
	call	delay
	call	ckint
	pop	b
	dcr	c
	jnz	stepi
	jmp	trk00
delay	lhld	dtime
	xchg
delp	dcx	d
	mov	a,e
	ora	d
	jnz	delp
	ret
ckint	lda	djiost
	ani	djdr
	rnz
	lda	djdata
	jmp	wboot

pbuff	mvi	c,9
	CALL	BDOS
	RET
SGNON	DB	ACR,ALF
	DB	'STEPPING 0 TO 200 & BACK$'
buferr	db	acr,alf
	db	'Buffer error$'
noclr	db	acr,alf
	db	'Toggle Write Protect did not clear Write Fault$'
ntrdy	db	acr,alf
	db	'Drive Not Ready$'
wrflms	db	acr,alf
	db	'Write Fault$'
nothlt	db	acr,alf
	DB	'NOT HALTED$'
DTIME	DW	100H