;Hercules Graphics Card driver
;**************************************************************************
;*			    DEVICE SPECIFIC ROUTINES			  *
;*									  *   
;*		These routines and equates are device dependant.	  *
;*									  *
;*									  *
;*									  *
;**************************************************************************
;Hist
;Name	Date	Modification
;DH	9/29/83 Added background color
;DH	9/29/83 Added choice possibility for character returned
;DH	11/9/83 Added microsoft mouse option to driver
;DH	12/28/83 removed microsoft mouse option from driver (in mouse.a86)
;
dseg
	copyright	db	'GSX-86 V1.3	   28 Dec  83'
			db	'IBM hercules   screen driver'
			db	'Serial No. XXXX-0000-654321 '
			db	'Digital Research, Inc.      '
cseg
;
	public	clearmem
	public	check_escape
	public	escfn0,escfn1,escfn2,escfn3
	public	escfn4,escfn5,escfn6,escfn7
	public	escfn8,escfn9,escf10,escf11
	public	escf12,escf13,escf14,escf15
	public	escf16,escf17,escf18,escf19
	public	concat
	public	valuator,choice,get_char
	public	plyfill_rot
	public	abline,draw_char
	public	next_address
	public	enable_cross,move_cross,clip_cross,get_loc_key
	public	device_table ,	size_table
	public	gcurx,gcury
	public	y1,y2,x1,x2
	public	lstlin
	public	arstl2
;
	extrn	entry:near		;the place to jump to if this module
					;is linked in first
;
;integer array indexing equates
	W_1	equ	word ptr 0
	W_2	equ	word ptr 2
	W_3	equ	word ptr 4
	W_4	equ	word ptr 6
	W_5	equ	word ptr 8
	W_6	equ	word ptr 10
	W_7	equ	word ptr 12
	W_8	equ	word ptr 14
	W_9	equ	word ptr 16
	W_10	equ	word ptr 18
;
false		equ	0
true		equ	not false
val_inc_big	equ	10			;maximum valuator increment
val_inc_small	equ	1			;minimum valuator increment
EJECT
;****************************************************************
;		screen coordinate equates			*
;   these must be changed to the values for specific machines	*
;****************************************************************
;
xresmx		equ	719			;X - Maximum resolution.
yresmx		equ	347			;Y - Maximum resolution.
xsize		equ	68			;size of pixel in microns
ysize		equ	91			;
graph_plane	equ	0b800h			;start of graphics segment
plane_size	equ	08000h			;size of graphics memory
msb_first	equ	true			;set if msb is first out 
byte_swap	equ	false
multiseg	equ	true
num_segs	equ	4			;number of graphics segments
bytes_line	equ	90			;used to compute addresses
chars_line	equ	80			;number of characters per line
lines_page	equ	24			;lines per alpha screen
last_escape	equ	19			;last escape function id
last_dri_escape equ	19			;last dri defined escape
mouse		equ	true			;is mouse available
;
;
;****************************************************************
;		    device dependant equates			*
;   these may or may not be necessary depending on hardware	*
;****************************************************************
;
if multiseg
next_line	equ	plane_size / num_segs	;offset to get to next segment
else
next_line	equ	bytes_line
endif
neg_next_line	equ	0-next_line
move_to_first	equ	0-plane_size+bytes_line
move_to_last	equ	plane_size-bytes_line	;from before first to last
curwtx		equ	16			;1/2 width of cross hair
curwty		equ	12			;1/2 height of cross hair
cur_mot_max_x	equ	16			;how far cursor moves fast in x
cur_mot_max_y	equ	8			;how far cursor moves fast in y
cur_mot_min_x	equ	1			;how far cursor moves slow in x
cur_mot_min_y	equ	1			;how far cursor moves slow in y
;
;****************************************************************
;		IBM STANDARD ROM BIOS CALLS			*
;****************************************************************
SCREEN	equ	10H		;interrupts to use for rom routine I/O
KEYBD	equ	16H
rev_vid_on	equ	70h		;turn on reverse video bits
rev_vid_off	equ	07h		;turn off reverse video bits 
;
read_cur_pos	equ	3			;bios rom calls for char I/O
set_cur_pos	equ	2
read_char	equ	8
write_char	equ	9
set_palette	equ	0bh
get_character	equ	0			;keyboard read
;
EJECT
;
	jmp	entry		;if we come in from here, go to real entry
;
;****************************************
;* clearmem				*
;*	    clears graphics memory	*
;*	    uses ax,cx,di		*
;*    stores zeros in graphics plane	*
;****************************************
clearmem:
	mov	ax,graph_plane		; ld in graphics memory address
	mov	es,ax
	mov	cx,plane_size/2 	;number of bytes to zero
	mov	al,bakcol
	mov	ah,al
	mov	di,0
	rep	stosw			; store plane_size zeros in graphmem
	ret
;
;************************************************************************
;*			escape functions				*
;*	 handle character I/O , alpha and graphics cursor		*
;*									*
;*	ENTRY								*
;*		contrl	points to segment and offset of contrl		*
;*		intin	points to segment and offset of intin		*
;*		ptsin	points to segment and offset of ptsin		*
;*		intout	points to segment and offset of intout		*
;*		ptsout	points to segment and offset of ptsout		*
;*									*
;*									*
;************************************************************************
;
;****************************************
;check_escape				*
;	checks escape function called	*
;	against last_escape		*
;****************************************
check_escape:
	cmp	bx,last_dri_escape
	jna	its_ok
	cmp	bx,last_escape
	ja	not_ok
	sub	bx,40
	jmps	its_ok
not_ok: 
	xor	bx,bx			;do a nop if its not valid
its_ok:
	ret
;
;****************************************
;escape func 0
; Nop
;****************************************	
escfn0:
	ret
;
;****************************************	
;escape func 1
; Inquire Addressable Character Cells
;****************************************	
escfn1:
	les	di,intout
	mov	es:W_1[di], lines_page	; number of addressable rows. 
	mov	es:W_2[di], chars_line	; number of addressable columns.
	ret
;****************************************	
;escape func 2
; Enter Graphics Mode 
;****************************************	
escfn2: 				; 
	call	escfn8			; home alpha cursor.
	call	escfn9			; clear alpha display.
	call	clearmem		; clear graphics display
	mov	si,offset crt_init_table_g
	mov	al,82h
	call	crt_init
if mouse
	mov	bl,1
	call	mouse_function		;initialize the mouse
endif
	ret
;
;****************************************	
;escape func 3
; Exit Graphics Mode
;****************************************	
escfn3: 				; 
	call	clearmem		; clear graphics display.
	mov	si,offset crt_init_table_a
	mov	al,20h			; alpha mode
	call	crt_init
	mov	attribute,rev_vid_off
	call	escfn8			;home
	call	escfn9			;clear to end of screen
if mouse
	mov	bl,2			;de init the mouse
	call	mouse_function
endif
	ret
;
;*****************************************************************
;crt_init
;	initializes the display controller with data from table
;*****************************************************************
crt_init:
	push	ax
	mov	dx,3b8h
	out	dx,al
	mov	dx,03b4h		;select port
	mov	cx,12
	xor	ah,ah
crt_init_loop:
	mov	al,ah
	out	dx,al
	inc	dx
	lodsb
	out	dx,al
	inc	ah
	dec	dx
	loop	crt_init_loop
	mov	dx,3b8h
	pop	ax
	add	al,8
	out	dx,al
	ret
;
;****************************************	
;escape func 4
; Cursor Up
;****************************************	
escfn4:
	mov	ah,read_cur_pos
	int	screen
	cmp	dh,0			;is cursor at top of screen
	jz	escfn4done		;if so, then done
	dec	dh
	mov	ah,set_cur_pos
	int	screen
escfn4done:
	ret
;
;****************************************	
;escape func 5
; Cursor Down
;****************************************	
escfn5:
	mov	ah,read_cur_pos
	int	screen
	cmp	dh,lines_page		;is cursor at bottom of screen?
	jz	escfn5done		;if so, done
	inc	dh
	mov	ah,set_cur_pos
	int	screen
escfn5done:
	ret
;
;****************************************	
;escape func 6
; Cursor Right
;****************************************	
escfn6:
	mov	ah,read_cur_pos
	int	screen
	cmp	dl,chars_line		;is cursor at edge of screen?
	jz	escfn6done		;if so, done
	inc	dl
	mov	ah,set_cur_pos
	int	screen
escfn6done:
	ret
;
;****************************************	
;escape func 7
; Cursor Left
;****************************************	
escfn7:
	mov	ah,read_cur_pos
	int	screen
	cmp	dl,0			;is cursor at edge of screen?
	jz	escfn7done		;if so, done
	dec	dl
	mov	ah,set_cur_pos
	int	screen
escfn7done:
	ret
;
;****************************************	
;escape func 8
; Home Cursor
;****************************************	
escfn8:
	mov	dx,0
	mov	ah,set_cur_pos
	int	screen			; move cursor home
	ret
;
;****************************************	
;escape func 9
; Erase to end of screen
;****************************************	
escfn9:
	mov	ah,read_cur_pos 	;get current cursor position
	int	screen
	push	dx			;save it 
	xor	cx,cx
	mov	cl,dl			;compute number of spaces to write
	neg	cl
	add	cl,bytes_line		;wrap cl around bytes_line
	xor	ax,ax
	mov	al,dh			;add bytes_line * number of columns
	neg	al
	add	al,lines_page
	dec	al			;don't count the line we're on
	mov	bl,bytes_line
	mul	bl			;bl=number of lines * bytes_line
	add	cx,ax
	dec	cx			;that last spot causes scroll
	mov	bx,rev_vid_off		;page zero and reverse off
	mov	ah,write_char
	mov	al,20h
	int	screen			;write cx spaces out
	pop	dx			;get original cursor position
	mov	ah,set_cur_pos
	int	screen			;restore cursor position
	ret
;
;****************************************	
;escape func 10
; Erase to end of line
;****************************************	
escf10:
	mov	ah,read_cur_pos 	;get current cursor position
	int	screen
	push	dx			;save it 
	xor	cx,cx
	mov	cl,dl			;compute number of spaces to write
	neg	cl
	add	cl,bytes_line
	mov	bx,rev_vid_off		;page zero and everything to black
	mov	al,20h
	mov	ah,write_char
	int	screen			;write cx spaces out
	pop	dx
	mov	ah,set_cur_pos
	int	screen			;restore cursor position
	ret
;
;****************************************	
;escape func 11
; Move Cursor to x,y
;****************************************	
escf11:
	les	di,intin
	mov	ax, es:[di]			; get the row number (1-24)
	mov	dh,al
	dec	dh				; make zero relative
	mov	ax, es: W_2[di] 		; get the column number (1-80)
	mov	dl,al
	dec	dl				; zero relative
	mov	ah,set_cur_pos
	mov	bx,0				;page zero
	int	screen
	ret
;
;****************************************	
;escape func 12
; Output text
;****************************************	
escf12:
	les	di,contrl
	mov	cx, es: W_4[di] 	; get string length.
	and	cx, cx			; test if 0 count
	jz	esc12_done
	les	di,intin
esc120:
	mov	al, es:[di]	; load character to be output.	
	push	es
	push	di
	push	cx
	mov	cx,1
	xor	bx,bx
	mov	bl,attribute
	mov	ah,write_char
	int	screen
	call	escfn6
	pop	cx
	pop	di 
	pop	es
	inc	di
	inc	di
	loop	esc120
esc12_done:
	ret
;****************************************	
;escape func 13     
; Reverse video on
;****************************************	
escf13:
	mov	attribute,rev_vid_on
	ret
;
;****************************************	
;escape func 14
; Reverse video off
;****************************************	
escf14:
	mov	attribute,rev_vid_off
	ret
;
;****************************************	
;escape func 15
; Return Current Cursor Address 
;****************************************	
escf15:
	les	di,intout
	mov	ah,read_cur_pos
	int	screen
	xor	ax,ax			;zero high byte
	mov	al,dh
	inc	al			;make one relative
	mov	es:[di],ax		;return row address
	mov	al,dl
	inc	al
	mov	es:W_2[di],ax		;return column address
	ret
;
;****************************************	
;escape func 16
; Return Tablet Status
;****************************************	
escf16:
	les	di,intout
if mouse
	mov	es:W_1[di],1		;if mouse then return 1
else
	mov	es:W_1[di], 0		;else return a 0
endif
	ret
;
;****************************************	
;escape func 17 	NOT SUPPORTED
; Hard Copy
;****************************************	
escf17:
	ret
;
;****************************************	
;escape func 18
; Place graphic cross-hair cursor at x,y
;****************************************	
escf18:
	les	di,ptsin
	mov	ax,es:[di]
	mov	gcurx,ax
	mov	ax,es:W_2[di]
	mov	gcury,ax
	call	enable_cross
	ret				;      locator is called before esc19.
;****************************************	
;escape func 19
; Remove cursor /Marker 
;****************************************	
escf19:
	call	enable_cross
esc19d: ret
;****************************************
;escape func 60
; select palette
; intin[1]=0 for RGB
;	   1 for Cyan,Magenta,White
;***************************************
escf60:
	les	di,intin
	mov	bl,es:[di]
	mov	bh,1
	mov	ah,11
	int	SCREEN
	ret
EJECT
;****************************************************************
;CONCAT 							*	
;	ENTRY	Reg. BX - X-coordinate (dev. coord.)		*
;		Reg. AX - Y-coordinate (dev. coord.)		*
;								*
;	EXIT	Reg. DI - Physical address			*
;		Reg. BL - Byte index				*	
;								*
;	Reg. Used. AX, BX, CX, DX, DI				*
;								*
;****************************************************************
concat:
	and	bx, 03ffh		;mask off 10 lsb for x-coord.
	mov	cx, yresmx		;normalize y-coordinate
	sub	cx, ax
	mov	ax, cx
	shr	ax,1
	shr	ax,1
	mov	dh,cl
	mov	dl, bl			;save low order byte of x-coord
	and	dl, 07h 		;mask off data bit index.
	mov	cl, 3			;set count to 3
	shr	bx, cl			;shift out 3 lsb of x-coord.
	mov	cl,bytes_line
	mul	cl			;brute force calculation
					;use shift and add if possible
	add	ax, bx			;concatenate y and x coordinates in AX
	and	dh,3
	jz	concat1
	mov	cl,dh
	xor	ch,ch
concat0:
	add	ax,next_line		;if odd address, then start at next_line
	loop	concat0
concat1:mov	di, ax			;di = memory address
	xor	dh, dh
	mov	bx, dx			;bx = bit index into data byte
	ret
EJECT
;
;************************************************************************
;*get_loc_key								*
;*	Get Locator key 						*
;*		Entry  none						*
;*		Exit							*
;*			al=0 nothing happened				*
;*									*
;*			al=1 button press				*
;*				ah = character information		*
;*									*
;*			al=2 coordinate information			*
;*				bx = delta x				*
;*				cx = delta y				*
;*									*
;*									*
;************************************************************************
get_loc_key:
if mouse
	mov	bl,3
	call	mouse_function
	and	al,al
	jz	get_loc_mouse
	ret 
get_loc_mouse:
endif		     
	mov	ah,1
	int	KEYBD			;see if ros has character
	jz	get_loc_key_none
	xor	ah,ah
	int	KEYBD
	mov	si,offset loc_tbl
	mov	cx,10			;search table for locator key
loc_key_search:
	cmp	ax,[si]
	jz	found_loc_key
	add	si,6
	loop	loc_key_search
	mov	ah,al
	mov	al,1			;not a locator key so return status
	ret
found_loc_key:
	add	si,2
	mov	bx,[si] 	;get delta x value
	add	si,2
	mov	cx,[si]
	mov	al,2
	ret
get_loc_key_none:
	xor	al,al
	ret
include mouse.a86
EJECT
;************************************************************************
;*valuator								*
;*	Get valuator increment						*
;*		Exit							*
;*			al=0 nothing happened				*
;*									*
;*			al=1 button press				*
;*				ah = character information		*
;*									*
;*			al=2 coordinate information			*
;*				bx = delta value			*
;*									*
;************************************************************************
valuator:
	mov	ah,1
	int	KEYBD			;see if ros has character
	jz	get_val_none
	xor	ah,ah
	int	KEYBD
	mov	si,offset val_tbl
	mov	cx,4			;search table for locator key
val_key_search:
	cmp	ax,[si]
	jz	found_val_key
	add	si,4
	loop	val_key_search
	mov	ah,al
	mov	al,1			;not a locator key so return status
	ret
found_val_key:
	add	si,2
	mov	bx,[si] 	;get delta x value
	mov	al,2
	ret
get_val_none:
	xor	ax,ax
	ret
EJECT
;
;************************************************************************
;*  Get choice for choice input 					*
;*		Entry  none						*
;*									*
;*		Exit							*
;*			al=0 nothing happened				*
;*									*
;*			al=1 choice value				*
;*				bx = choice number 1 to max choice keys *
;*									*
;*			al=2 button press				*
;*				ah = character				*
;*									*
;************************************************************************
choice:
	mov	ah,1
	int	KEYBD			; see if ros has character
	jz	choice_none
	xor	ah,ah
	int	KEYBD
	mov	bl,ah			; swap byte choice runs from 3b00-4400
	mov	bh,al
	sub	bx,3bh
	jc	choice_key		; make it zero based if <0 then reject
	cmp	bx,10			; test if too large
	jnc	choice_none
	inc	bx			; make 1-10
	xor	ah,ah
	mov	al,1			; bx = choice number
	ret
choice_key:
	mov	ah,al
	mov	al,2
	ret
choice_none:
	xor	al,al
	ret
EJECT
;
;************************************************************************
;*get_char								*
;*	Get character for string input					*
;*		Entry  none						*
;*									*
;*		Exit							*
;*			al=0 nothing happened				*
;*									*
;*			al=1 button press				*
;*				bx = character information		*
;*									*
;************************************************************************
get_char:
	mov	ah,1
	int	KEYBD			; see if ros has character
	jz	get_char_none
	xor	ah,ah
	int	KEYBD
	mov	bl,al
	xor	bh,bh
	mov	al,1			; return character in bx status in al
	ret
get_char_none:
	xor	al,al
	ret
EJECT
;
include monommre.a86
dseg
;***************************************************************************
;*									   *
;*				Data Area				   *
;*		     contains data for escape functions 		   *
;*		and the values returned on open_workstation		   *
;*									   *
;*									   *
;*									   *
;***************************************************************************
;
	extrn	txtclx:word	;text color index
	extrn	txtcol:byte	;text writing mode
	extrn	wrmode:word	;writing mode
	extrn	plncol:byte	;polygon color index
	extrn	bakcol:byte	;back ground color
	extrn	style:word	;line style
	extrn	contrl:dword 
	extrn	intin:dword 
	extrn	ptsin:dword 
	extrn	intout:dword 
	extrn	ptsout:dword 
;
;
crt_init_table_g   db	35h,2dh,2eh,07h
		   db	5bh,2h,57h,57h
		   db	2,3,0,0
;
crt_init_table_a   db	61h,50h,52h,0fh,19h,6h,19h,19h,2,0dh,0bh,0ch
;
;
attribute	   db	07h		;text attributes
;
;loc_tbl
;	table of words for locator keys
;		format
;			word = key code
;			word = delta x
;			word = delta y
loc_tbl dw	4d00h	;right arrow un shifted
	dw	cur_mot_max_x
	dw	0
	dw	4d36h	;right arrow shifted
	dw	cur_mot_min_x
	dw	0
	dw	4b00h	;left arrow unshifted
	dw	0-cur_mot_max_x
	dw	0
	dw	4b34h	;left arrow shifted
	dw	0-cur_mot_min_x
	dw	0
	dw	4800h	;up arrow unshifted
	dw	0
	dw	cur_mot_max_y
	dw	4838H	;up arrow shifted
	dw	0
	dw	cur_mot_min_y
	dw	5000h	;down arrow unshifted
	dw	0
	dw	0-cur_mot_max_y
	dw	5032h	;down arrow shifted
	dw	0
	dw	0-cur_mot_min_y
	dw	4700h	;home un shifted
	dw	0-xresmx
	dw	0-yresmx
	dw	4737h	;home shifted
	dw	0-xresmx
	dw	0-yresmx
;
;val_tbl
;    decoding of valuator input
;
val_tbl dw	4800h	;up arrow unshifted
	dw	val_inc_big
	dw	4838H	;up arrow shifted
	dw	val_inc_small
	dw	5000h	;down arrow unshifted
	dw	0-val_inc_big
	dw	5032h	;down arrow shifted
	dw	0-val_inc_small
;