diff --git a/gr0.asm b/gr0.asm
new file mode 100644
index 0000000..cc15ecb
--- /dev/null
+++ b/gr0.asm
@@ -0,0 +1,355 @@
+	IDEAL
+	P386
+	MODEL	TINY
+	CODESEG
+	ORG	100h
+	include	'fox.mak'
+smartio	=	1
+
+start:
+	db	2048 dup(0)	;compack
+
+o_a	=	1
+o_b	=	2
+o_c	=	4
+o_d	=	8
+o_f	=	10h
+o_i	=	20h
+o_l	=	40h
+o_n	=	80h
+o_x	=	100h
+
+MACRO	topt	_op
+	testflag dx, _op
+	ENDM
+
+	mov	si, 81h
+	mov	bx, 0ff00h	;bh=attr mask, bl=attr set
+	xor	dx, dx		;m_xxx
+
+gsw1:	lodsb
+	cmp	al, ' '
+	je	gsw1
+	cmp	al, 9
+	je	gsw1
+	cmp	al, 0dh
+	je	gswx
+	cmp	al, '/'
+	je	gsw2
+	cmp	al, '-'
+	je	gsw2
+usage:	mov	dx, offset usgtxt
+panic:	print
+	int	20h
+
+	smartdisk
+
+rdpage:	mov	cx, 100h
+	fread
+	cmp	ax, 100h
+	jb	_derr
+	ret
+
+rdnum:	lodsb
+	cmp	al, ':'
+	jne	usage
+	lodsw
+	cmp	al, '9'
+	ja	usage
+	sub	al, '0'
+	jb	usage
+	cmp	ah, '9'
+	ja	rdnum1
+	sub	ah, '0'
+	jb	rdnum1
+	xchg	al, ah
+	aad		;al:=10*ah+al
+	cmp	al, 15
+	ja	usage
+	ret
+rdnum1:	dec	si
+	ret
+
+gsw2:	lodsb
+	and	al, 0dfh
+	mov	di, offset swilet
+	mov	cx, 9
+	repne	scasb
+	jne	usage
+	bts	dx, cx
+	jc	usage
+	cmp	al, 'B'
+	je	sw_b
+	cmp	al, 'C'
+	je	sw_c
+	cmp	al, 'F'
+	je	sw_f
+	jmp	gsw1
+
+sw_b:	call	rdnum
+	shl	al, 4
+	and	bh, 0fh
+	or	bl, al
+	jmp	gsw1
+
+sw_c:	call	rdnum
+	and	bh, 0f0h
+	or	bl, al
+	jmp	gsw1
+
+sw_f:	cmp	[byte si], ':'
+	jne	usage
+	mov	di, offset fname-1
+swf1:	movsb
+	cmp	[byte si], ' '
+	je	swf2
+	cmp	[byte si], 9
+	je	swf2
+	cmp	[byte si], 0dh
+	jne	swf1
+swf2:	pusha
+	mov	bx, di
+	mov	cx, di
+	sub	cx, offset fname
+	je	usage
+adex1:	dec	bx
+	cmp	[byte bx], '.'
+	je	adexn
+	cmp	[byte bx], '\'
+	loopne	adex1
+adex2:	mov	eax, 'TNF.'
+	stosd
+adexn:	mov	[byte di], 0
+
+	fopen	fname
+	mov	dx, offset font+100h	;digits
+	call	rdpage
+	mov	dx, offset font+200h	;letters
+	call	rdpage
+	mov	dx, offset font		;controls
+	call	rdpage
+	mov	dx, offset font+300h	;low letters
+	call	rdpage
+	fclose
+	popa
+	jmp	gsw1
+
+gswx:	test	dx, dx
+	jz	usage
+
+	topt	o_a	;obsluz opcje a
+	jz	atrok
+	setflag	dx, o_n+o_l
+	topt	o_b
+	jnz	anob
+	and	bx, 0f0fh
+	or	bl, 10h
+anob:	topt	o_c
+	jnz	anoc
+	and	bx, 0f0f0h
+	or	bl, 7
+anoc:	topt	o_d+o_f+o_x
+	jnz	atrok
+	setflag	dx, o_x
+atrok:
+
+	mov	ax, dx	;sprawdz opcje fontu
+	and	ax, o_d+o_f+o_x
+	jz	nofnt	
+	bsf	cx, ax	;dozwolona max 1 z opcji d,f,x
+	btr	ax, cx
+	test	ax, ax
+	jz	fntok
+	jmp	usage
+nofnt:	topt	o_l	;jezeli l i zadna z d,f,x, to ustaw d
+	jz	fntok
+	setflag	dx, o_d
+fntok:
+
+	push	bx
+
+; inicjuj tryb tekstowy
+	topt	o_n
+	jz	noini
+	push	dx
+	mov	ax, 3
+	int	10h
+	pop	dx
+noini:
+
+; wczytaj font domyslny
+	topt	o_d
+	jz	nodef
+	mov	ax, 1112h
+	topt	o_l
+	jnz	def50
+	mov	al, 14h
+def50:	push	dx
+	int	10h
+	pop	dx
+nodef:
+
+; wczytaj font uzytkownika
+	topt	o_f+o_x
+	jz	nocust
+
+; ustaw odpowiedni font
+	mov	cx, 128
+	topt	o_i
+	jz	noinv
+; inwertuj znaki 0-127 na 128-255
+	mov	si, offset font
+	mov	di, offset ifont
+	mov	cx, 1024
+mkinv:	lodsb
+	not	al
+	stosb
+	loop	mkinv
+	mov	cx, 256
+noinv:	mov	bp, offset font
+	mov	bx, 800h
+	topt	o_l
+	jnz	nodbl
+; rob font o podwojonej wysokosci
+	mov	si, offset font
+	mov	di, offset dfont
+	push	cx
+	mov	cx, 2048
+mkdbl:	lodsb
+	mov	ah, al
+	stosw
+	loop	mkdbl
+	pop	cx
+	mov	bp, offset dfont
+	mov	bh, 16
+nodbl:	push	dx
+	xor	dx, dx
+	mov	ax, 1110h
+	int	10h
+	pop	dx
+
+nocust:
+; jezeli przelaczylismy 50->25 to skorygowac polozenie kursora
+	topt	o_l
+	jnz	nococu
+	topt	o_d+o_f+o_x
+	jz	nococu
+	xor	bh, bh
+	mov	ah, 3
+	int	10h	;wez pozycje kursora
+	sub	dh, 25
+	jb	nococu
+	xor	bh, bh
+	mov	ah, 2
+	int	10h	;ustaw kursor
+	mov	ax, 0b800h	;przesuwa dolna polowke ekranu do gory
+	mov	ds, ax
+	mov	es, ax
+	mov	si, 2*80*25
+	xor	di, di
+	mov	cx, si
+	rep	movsb
+	mov	ax, [di]	;czysci dolna polowke
+	mov	al, ' '
+	mov	cx, 80*25
+	rep	stosw
+	push	cs
+	pop	ds
+	push	cs
+	pop	ds
+
+nococu:
+; ustaw kolory
+	pop	bx
+	cmp	bh, 0ffh
+	je	nocol
+	push	0b800h
+	pop	es
+	xor	di, di
+	mov	cx, 80*50
+cls:	inc	di
+	and	[es:di], bh
+	or	[es:di], bl
+	inc	di
+	loop	cls
+nocol:	ret
+
+swilet	db	'XNLIFDCBA'
+usgtxt	db	'GR0 version 1.0 by Fox/Taquart',eol
+	db	'Customizes DOS screen.',eol
+	db	'Available options:',eol
+	db	'/a       Set Atari scheme = /b:1 /c:7 /n /l /x',eol
+	db	'/b:nn    Set background color 0-15',eol
+	db	'/c:nn    Set foreground color 0-15',eol
+	db	'/d       Set default PC font',eol
+	db	'/f:fname Set external Atari font',eol
+	db	'/i       Set chars 128-255 to inverse',eol
+	db	'/l       Select 50 lines font',eol
+	db	'/n       Initialize text mode (clears screen)',eol
+	db	'/x       Set Atari build-in font',eot
+	smarterr
+
+font	db	0,54,127,127,62,28,8,0,24,24,24,31,31,24,24,24,3
+	db	3,3,3,3,3,3,3,24,24,24,248,248,0,0,0,24,24,24
+	db	248,248,24,24,24,0,0,0,248,248,24,24,24,3,7,14,28,56
+	db	112,224,192,192,224,112,56,28,14,7,3,1,3,7,15,31,63,127
+	db	255,0,0,0,0,15,15,15,15,128,192,224,240,248,252,254,255,15
+	db	15,15,15,0,0,0,0,240,240,240,240,0,0,0,0,255,255,0
+	db	0,0,0,0,0,0,0,0,0,0,0,255,255,0,0,0,0,240
+	db	240,240,240,0,28,28,119,119,8,28,0,0,0,0,31,31,24,24
+	db	24,0,0,0,255,255,0,0,0,24,24,24,255,255,24,24,24,0
+	db	0,60,126,126,126,60,0,0,0,0,0,255,255,255,255,192,192,192
+	db	192,192,192,192,192,0,0,0,255,255,24,24,24,24,24,24,255,255
+	db	0,0,0,240,240,240,240,240,240,240,240,24,24,24,31,31,0,0
+	db	0,120,96,120,96,126,24,30,0,0,24,60,126,24,24,24,0,0
+	db	24,24,24,126,60,24,0,0,24,48,126,48,24,0,0,0,24,12
+	db	126,12,24,0,0,0,0,0,0,0,0,0,0,0,24,24,24,24
+	db	0,24,0,0,102,102,102,0,0,0,0,0,102,255,102,102,255,102
+	db	0,24,62,96,60,6,124,24,0,0,102,108,24,48,102,70,0,28
+	db	54,28,56,111,102,59,0,0,24,24,24,0,0,0,0,0,14,28
+	db	24,24,28,14,0,0,112,56,24,24,56,112,0,0,102,60,255,60
+	db	102,0,0,0,24,24,126,24,24,0,0,0,0,0,0,0,24,24
+	db	48,0,0,0,126,0,0,0,0,0,0,0,0,0,24,24,0,0
+	db	6,12,24,48,96,64,0,0,60,102,110,118,102,60,0,0,24,56
+	db	24,24,24,126,0,0,60,102,12,24,48,126,0,0,126,12,24,12
+	db	102,60,0,0,12,28,60,108,126,12,0,0,126,96,124,6,102,60
+	db	0,0,60,96,124,102,102,60,0,0,126,6,12,24,48,48,0,0
+	db	60,102,60,102,102,60,0,0,60,102,62,6,12,56,0,0,0,24
+	db	24,0,24,24,0,0,0,24,24,0,24,24,48,6,12,24,48,24
+	db	12,6,0,0,0,126,0,0,126,0,0,96,48,24,12,24,48,96
+	db	0,0,60,102,12,24,0,24,0,0,60,102,110,110,96,62,0,0
+	db	24,60,102,102,126,102,0,0,124,102,124,102,102,124,0,0,60,102
+	db	96,96,102,60,0,0,120,108,102,102,108,120,0,0,126,96,124,96
+	db	96,126,0,0,126,96,124,96,96,96,0,0,62,96,96,110,102,62
+	db	0,0,102,102,126,102,102,102,0,0,126,24,24,24,24,126,0,0
+	db	6,6,6,6,102,60,0,0,102,108,120,120,108,102,0,0,96,96
+	db	96,96,96,126,0,0,99,119,127,107,99,99,0,0,102,118,126,126
+	db	110,102,0,0,60,102,102,102,102,60,0,0,124,102,102,124,96,96
+	db	0,0,60,102,102,102,108,54,0,0,124,102,102,124,108,102,0,0
+	db	60,96,60,6,6,60,0,0,126,24,24,24,24,24,0,0,102,102
+	db	102,102,102,126,0,0,102,102,102,102,60,24,0,0,99,99,107,127
+	db	119,99,0,0,102,102,60,60,102,102,0,0,102,102,60,24,24,24
+	db	0,0,126,12,24,48,96,126,0,0,30,24,24,24,24,30,0,0
+	db	64,96,48,24,12,6,0,0,120,24,24,24,24,120,0,0,8,28
+	db	54,99,0,0,0,0,0,0,0,0,0,255,0,0,24,60,126,126
+	db	60,24,0,0,0,60,6,62,102,62,0,0,96,96,124,102,102,124
+	db	0,0,0,60,96,96,96,60,0,0,6,6,62,102,102,62,0,0
+	db	0,60,102,126,96,60,0,0,14,24,62,24,24,24,0,0,0,62
+	db	102,102,62,6,124,0,96,96,124,102,102,102,0,0,24,0,56,24
+	db	24,60,0,0,6,0,6,6,6,6,60,0,96,96,108,120,108,102
+	db	0,0,56,24,24,24,24,60,0,0,0,102,127,127,107,99,0,0
+	db	0,124,102,102,102,102,0,0,0,60,102,102,102,60,0,0,0,124
+	db	102,102,124,96,96,0,0,62,102,102,62,6,6,0,0,124,102,96
+	db	96,96,0,0,0,62,96,60,6,124,0,0,24,126,24,24,24,14
+	db	0,0,0,102,102,102,102,62,0,0,0,102,102,102,60,24,0,0
+	db	0,99,107,127,62,54,0,0,0,102,60,24,60,102,0,0,0,102
+	db	102,102,62,12,120,0,0,126,12,24,48,126,0,0,24,60,126,126
+	db	24,60,0,24,24,24,24,24,24,24,24,0,126,120,124,110,102,6
+	db	0,8,24,56,120,56,24,8,0,16,24,28,30,28,24,16,0
+fname:
+ifont	db	1024 dup(?)
+
+dfont	db	4096 dup(?)
+
+	ENDS
+	END	start
\ No newline at end of file