;
; usage: SETPATH pathstring
;
; DOS+ utility.  For run-time configuration of DOS+.
;
; 1.1	87/01/10 Reduced messages so passworded version is smaller.
;
@flags	equ	018h;		BDOS offset to flags byte, base page
@path	equ	014h;		BDOS offset to path address
;
; DOS+/CPM  calls
tstr	equ	9
cpmver	equ	12
getinfo	equ	210;		e = 0 returns BDOS base address
;
bdos	equ	5
defdma	equ	080h
;
cr	equ	0dh
lf	equ	0ah
dol	equ	'$'+80h;	So passes thru wrtstring
;
	jmp	bgn
;
; This message also defines the acceptable words. ']' terminates lists.
hlpmsg:	db	'usage: SETPATH string',cr,lf
	db	'  ex: SETPATH a0b1b2c',dol,cr,lf
	db	'to search A & C on user 0, B & C on users 1 & 2,'
	db	' C on all users.',cr,lf
	db	'      SETPATH ', dol, dol, '   (resets path)',cr,lf
	db	'Not protected against over-long input strings'
	db	' (installation dependant)$'
;
badpth:	db	'Invalid path string$'
badver:	db	'Needs DOS+ 2.4 up$'
nopath:	db	'No path location configured$'
;
; Start here
bgn:	lxi	h,0
	dad	sp
	lxi	sp,stack
	push	h
	lda	defdma
	ora	a
	jz	help;		empty command line, help
	mvi	c,cpmver;	Make sure running DOS+ 2.4 up
	call	bdos
	lxi	d,badver
	inr	h
	dcr	h
	jnz	msgxit;		not MPM etc
	cpi	22h
	jc	msgxit;		< 2.2, cant be compatible mode
	cpi	30h
	jnc	msgxit;		Can't use CPM 3
	cpi	24h
	jnc	bgn2;		ok, 2.4 thru 2.f
	call	getbas;		of DOS+, if running
	mov	a,h;		DOS+ returns base pointer
	ora	a;		CPM returns 0
	jz	msgxit;		not in compatible mode
;	"	"
; DOS+ running, check parameters and execute
bgn2:	call	getbas;		of DOS+
	mvi	l,@path;	point to configured path location
	mov	a,m
	inx	h
	mov	h,m
	mov	l,a
	ora	h
	lxi	d,nopath
	jz	msgxit;		no path configured
	xchg;			path pointer to de
	lxi	h,defdma
	mov	a,m;		length of command line
	inx	h
	push	h
	add	l
	mov	l,a
	adc	h
	sub	l
	mov	h,a;		point to end of string
	mvi	m,0;		and mark it
	pop	h;		
	call	skipbk;		initial empty line leaves old path
	jc	exit;		end of input string
	mov	a,m
	cpi	'?'
	jz	help
bgn3:	cpi	'$'
	jz	bgn4;		'$' ok, used to clear path only
	ani	05fh;		upshift to get drive idd
	cpi	'A'
	jc	badstg
	cpi	'P'+1;		max possible drive
	jnc	badstg
bgn4:	mov	b,a
	inx	h
	mov	a,m
	cpi	'$'
	cnz	getnum
	jc	badstg;		faulty input string
	inx	h
	mov	c,a;		b is drive, c is user
	mov	a,b
	stax	d
	inx	d
	mov	a,c
	stax	d
	inx	d
	xra	a
	stax	d;		tentative line end marker
	mov	a,m
	ora	a
	jnz	bgn3;		get next pair
;	"	"
; restore sp and exit
exit:	pop	h
	sphl
	ret	
;
; Bad string message and exit
badstg:	lxi	d,badpth
	jmp	msgxit
;
; Help message and exit
help:	lxi	d,hlpmsg
;	"	"
; Message de^ to console
msgxit:	mvi	c,tstr
	call	bdos
	jmp	exit
;
; skip blanks, string hl^
skipbk:	mov	a,m
	cpi	' '
	rnz;			carry for control, end marker
	inx	h
	jmp	skipbk
;
; get number (1 or 2 decimal digits) from input string hl^
; exit with hl pointing to last digit.  Cy for invalid number
getnum:	mov	a,m
	call	qnum;		exit error if non-digit
	rc
	ani	0fh
	mov	c,a
	inx	h
	mov	a,m;		possible 2nd digit
	call	qnum
	dcx	h;		in case 1 digit only
	cmc
	mov	a,c
	rnc	;		no 2nd digit
	add	a
	add	a;		4*
	add	c;		5*
	add	a;		10*
	mov	c,a
	inx	h
	mov	a,m
	ani	0fh
	add	c
	ret
;
; check (a) is decimal digit (ascii).  Carry if not
; f
qnum:	cpi	'0'
	rc
	cpi	'9'+1
	cmc
	ret
;
; Get BDOS base page, on DOS+.  CPM returns 0
; a,f,h,l
getbas:	push	b
	push	d
	mvi	c,getinfo
	mvi	e,0
	call	bdos;		get BDOS base page
	pop	d
	pop	b
	ret
	
	ds	48
stack:
	end