home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The C Users' Group Library 1994 August
/
wc-cdrom-cusersgrouplibrary-1994-08.iso
/
vol_100
/
199_01
/
gedio.asm
< prev
next >
Wrap
Assembly Source File
|
1987-12-17
|
29KB
|
1,016 lines
;------------------------------------------------------------------
; Gedio.asm: Screen and keyboard interface routines for the PC
;
; For GED WordStar-like screen editor
; DeSmet C implementation by Mel Tearle - 08/06/86
;
; Microsoft Macroassembler implementation by Michael Yokoyama - 12/06/86
; Revised by Mel Tearle - 07/25/87
;
; data starts here
;------------------------------------------------------------------
_data segment word public 'data'
const segment word public 'const'
const ends
_bss segment word public 'bss'
_bss ends
dgroup group const,_bss,_data
assume cs: _text, ds: dgroup, ss: dgroup, es: dgroup
; In this implementation, all special and function keys are translated
; to the following values.
; control key translations
; control key translations - mapped into cursor-pad.
up_char equ 5 ;arrow up
down_char equ 24 ;arrow down
left_char equ 19 ;arrow left
right_char equ 4 ;arrow right
bol_char equ 15 ;Home
eol_char equ 16 ;End
pageup_char equ 18 ;PgUp
pagedown_char equ 3 ;PgDn
Del_char equ 7 ;Del
; function key definitions
M1 equ 128
M2 equ 129
M3 equ 130
M4 equ 145
M5 equ 132
M6 equ 133
M7 equ 134
M8 equ 135
M9 equ 136
M10 equ 137
; special keys - toggles and keypress
Insert_key equ 138
Caps_Lock_on equ 139
Caps_Lock_off equ 140
Alt_key equ 146
grey_minus equ 142
grey_plus equ 143
; the table that is used to make the translation
; note - not all used
convert db 72, up_char
db 80, down_char
db 75, left_char
db 77, right_char
db 71, bol_char
db 79, eol_char
db 73, pageup_char
db 81, pagedown_char
; db 78, grey_plus
; db 74, grey_minus
db 82, Insert_key
db 83, Del_char
db 59, M1
db 60, M2
db 61, M3
db 62, M4
db 63, M5
db 64, M6
db 65, M7
db 66, M8
db 67, M9
db 68, M10
db 0, 255 ;illegal character
; equates for bios interface.
; the interrupt and codes for the screen interface interrupt.
video equ 10h ;interrupt for dealing with screen
mode equ 0 ;code for setting new screen mode
curtype equ 1 ;code for setting new cursor type
setcur equ 2 ;code for addressing cursor
readcur equ 3 ;code for reading cursor location
readlp equ 4 ;code for reading light pen position
setpage equ 5 ;code to select active page
scrollup equ 6 ;code to scroll screen up
scrolldn equ 7 ;code to scroll screen nown
readch equ 8 ;code to read a character from screen
writeach equ 9 ;code to write char and attributes
writech equ 10 ;code to write character only
setpal equ 11 ;code to set new setpal or border
wdot equ 12 ;code to write a dot
rdot equ 13 ;code to read a dot
wtty equ 14 ;code to write as if teletype
state equ 15 ;code to find current screen status
; used in set_video
mono_adr equ 0b000h ;mono adapter
graph_adr equ 0b800h ;graphics adapter*
vadrs dw 0
; the interrupt and codes for the keyboard interface.
keyboard equ 16h ;interrupt 16 to deal with keyboard
cicode equ 0 ;code for reading a character
cstscode equ 1 ;reports if character is ready
kbstatus equ 2 ;get keyboard status - shifts, caplocks
kbset db 0
; caution: must change column number if 40 column mode
crt_cols equ 80
; Note: 25 for MS-DOS, 24 for CP/M as cp/m steals the bottom line.
_scr_rows dw 24 ; current number of rows, for ged, was 25
_scr_cols dw crt_cols ; current number of columns
_scr_mode db 0 ; current screen mode
_scr_page db 0 ; current page
_scr_attr db 7 ; current attributes for screen
; 7 is white letters on black
_scr_window_top db 1 ; first line to scroll, was 0
_data ends
;------------------------------------------------------------------
; code starts here
;------------------------------------------------------------------
_text segment byte public 'code'
assume cs:_text
; Variables available to C programs
public _scr_cols, _scr_rows, _scr_xy, _scr_clr
public _scr_mode, _scr_page, _scr_attr, _scr_window_top
public _scr_setup, _scr_term, _scr_csts, _scr_setmode
public _scr_clrl, _scr_cls, _scr_scup, _scr_scrup
public _scr_scrdn, _scr_co, _scr_ci, _get_graphic
public _scr_sinp, _scr_cursoff, _scr_curson, _scr_mark
public _scr_putch, _scr_delete, _get_mode, _calc_video
public _scr_putstr, _scr_aputch, _get_kbstat, _caps_on
public _scr_scdn, _scr_aputs, _set_video
;-------------------------------------------------------------------------
; _scr_setup Call _scr_setup before using any other routine unless the
; starting mode is 80X25 character mode (3,4, or 7).
; This routine must be called for monochrome (mode 7)
; for _scr_curson to set a proper cursor.
;
; Usage: mode = _scr_setup();
;-------------------------------------------------------------------------
_scr_setup proc near
push bp
mov bp, sp
mov ah,state ; get current state
int video
mov _scr_mode, al ; current mode
mov cl,ah ; make cols a word
mov ch,0
mov _scr_cols, cx ; 40 or 80 columns
mov _scr_page, bh
mov _scr_attr, 7 ; set to white chars on black
cmp al, 4 ; see if a character mode
jc got_attr
cmp al, 7 ; 7 is for graphics mode
jz got_attr
mov _scr_attr, 0 ; attribute is zero in graphics
got_attr:
mov ah,0 ; return int containing mode
push ax ; slight detour
call _set_video ; get display address
pop ax
pop bp
ret
_scr_setup endp
;-------------------------------------------------------
; _scr_term Do any required termination.
;
; Usage: _scr_term();
;-------------------------------------------------------
_scr_term proc near
ret
_scr_term endp
;-------------------------------------------------------
; _scr_setmode Set a new screen mode.
;
; Usage: _scr_setmode(new mode);
;-------------------------------------------------------
_scr_setmode proc near
push bp
mov bp, sp
mov al, [bp+4] ; new mode value
mov ah, mode
int video ; set new mode
call _scr_setup ; remember new values
pop bp
ret
_scr_setmode endp
;-------------------------------------------------------
; _scr_xy Sets cursor at any location.
;
; Usage: _scr_xy( col, row );
;-------------------------------------------------------
_scr_xy proc near
push bp
mov bp, sp
mov dx, [bp+4] ; col
mov ax, [bp+6] ; row
mov dh, al
mov bh, _scr_page ; force page zero
mov ah, setcur ; set cursor location
int video ; call BIOS
pop bp
ret
_scr_xy endp
;-------------------------------------------------------
; _scr_clr Clear entire screen
;
; Usage: _scr_clr();
;-------------------------------------------------------
_scr_clr proc near
push bp
mov bp, sp
mov al, 0 ; ask for a clear window
xor cx, cx ; start at 0,0
mov dh, byte ptr _scr_rows ;last line
dec dh
mov dl, byte ptr _scr_cols ;clear entire width
dec dl ; last column is width-1
mov bh, _scr_attr ; attributes for new blanks
mov ah, scrollup ; ask for a scrollup to clear
int video ; do the clear
pop bp
ret
_scr_clr endp
;-------------------------------------------------------
; _scr_clrl Clear rest of line.
;
; Usage: _scr_clrl();
;-------------------------------------------------------
_scr_clrl proc near
push bp
mov bp, sp
mov bh, _scr_page
mov ah, readcur ; see where we are
int video
mov cl, byte ptr _scr_cols ; calc how many chars left in line
sub cl, dl ; number left
mov ch, 0 ; number of blanks needed
mov al, ' ' ; write blanks
mov bl, _scr_attr ; normal attributes
mov bh, _scr_page ; page number
mov ah, writeach ; write the blanks
int video
pop bp
ret
_scr_clrl endp
;-------------------------------------------------------
; _scr_cls Clear rest of screen starting at y
; set line pointer, clear screen, reset line pointer
;
; Usage: _scr_cls(y);
;-------------------------------------------------------
_scr_cls proc near
push bp
mov bp, sp
mov dx, 0 ; hard-code column at 0
mov ax, [bp+4] ; get row
mov dh, al
mov bh, _scr_page ; force page zero
mov ah, setcur ; set cursor location
int video ; call bios
call _scr_clrl ; clear rest of line
mov al, 0 ; ask for a clear window
mov ch, [bp+4] ; re-use row
inc ch ; bump row
cmp ch, byte ptr _scr_rows ; see if in last line
jz cleared ; all done
mov cl, 0 ; first column
mov dh, byte ptr _scr_rows ; 24 is the last line
dec dh
mov dl, byte ptr _scr_cols ; clear entire width
dec dl ; last column is width-1
mov bh, _scr_attr ; attributes for new blanks
mov ah, scrollup ; ask for a scrollup to clear
int video ; do the clear
cleared:
mov dx, 0 ; set column again
mov ax, [bp+4] ; get row
mov dh, al
mov bh, _scr_page ; force page zero
mov ah, setcur ; set cursor location
int video ; call bios
pop bp
ret
_scr_cls endp
;--------------------------------------------------------
; _scr_delete Clears rest of line starting at x,y.
;
; Usage: _scr_delete(x,y);
;--------------------------------------------------------
_scr_delete proc near
push bp
mov bp, sp
mov dx, [bp+4] ; col
mov ax, [bp+6] ; row
mov dh, al
mov bh, _scr_page ; force page zero
mov ah, setcur ; set cursor location
int video ; call BIOS
mov cl, byte ptr _scr_cols ; calc how many chars left in line
sub cl, dl ; number left
mov ch, 0 ; number of blanks needed
mov al, ' ' ; write blanks
mov bl, _scr_attr ; normal attributes
mov bh, _scr_page ; page number
mov ah, writeach ; write the blanks
int video
pop bp
ret
_scr_delete endp
;--------------------------------------------------------
; _scr_scup Scroll text up from last line to
; _scr_window_top, leaving top lines alone.
;
; Usage: _scr_scup();
;--------------------------------------------------------
_scr_scup proc near
mov ax, _scr_cols ; need last column of screen
dec ax
push ax
mov ax, _scr_rows ; scroll through last line
dec ax
push ax
xor ax, ax ; from column 0
push ax
mov al, _scr_window_top ;leave top line alone
push ax
mov al, 1
push ax ; scroll by 1
call _scr_scrup ; do the scroll
add sp, 10 ; clear arge
ret
_scr_scup endp
;---------------------------------------------------------------
; _scr_scrup Scroll the screen up. The window is scrolled
; up nline lines. A zero nline will clear the
; window. Top left of the screen in 0,0.
;
; Usage: _scr_scrup(nline,fromrow,fromcol,torow,tocol);
;---------------------------------------------------------------
_scr_scrup proc near
push bp
mov bp, sp
mov al, [bp+4] ; number of lines
mov ch, [bp+6] ; starting row
mov cl, [bp+8] ; starting column
mov dh, [bp+10] ; ending row
mov dl, [bp+12] ; ending column
mov bh, _scr_attr ; current attribute
mov ah, scrollup
int video ; do the scroll
pop bp
ret
_scr_scrup endp
;-------------------------------------------------------------
; _scr_scdn Scroll all but the top lines down one.
;
; Usage: _scr_scdn();
;-------------------------------------------------------------
_scr_scdn proc near
mov ax, _scr_cols ; need last column of screen
dec ax
push ax
mov ax, _scr_rows ; scroll through last line
dec ax
push ax
xor ax, ax ; from column 0
push ax
mov al, _scr_window_top ; leave top lines alone
push ax
mov al, 1
push ax ; scroll by 1
call _scr_scrdn ; do the scroll
add sp, 10 ; clear arge
ret
_scr_scdn endp
;---------------------------------------------------------------
; _scr_scrdn Scroll the screen down. the window is scrolled
; down nline lines. A zero nline will clear the
; window. Top left of the screen in 0,0.
;
; Usage: _scr_scrdn(nline,fromrow,fromcol,torow,tocol);
;---------------------------------------------------------------
_scr_scrdn proc near
push bp
mov bp, sp
mov al, [bp+4] ; number of lines
mov ch, [bp+6] ; starting row
mov cl, [bp+8] ; starting column
mov dh, [bp+10] ; ending row
mov dl, [bp+12] ; ending column
mov bh, _scr_attr ; current attribute
mov ah, scrolldn
int video ; do the scroll
pop bp
ret
_scr_scrdn endp
;---------------------------------------------------------------
; _scr_co Write a character to the screen TTY style. This
; routine increments the cursor position
; after writing.
;
; Usage: _scr_co(character);
;---------------------------------------------------------------
_scr_co proc near
push bp
mov bp, sp
mov al, [bp+4] ; character to write
mov bh, _scr_page
mov ah, wtty ; use tty write routine
int video
pop bp
ret
_scr_co endp
;---------------------------------------------------------------
; _scr_ci Keyboard input. function and soft keys are
; translated. see equates for values.
;
; Usage: character = _scr_ci();
;---------------------------------------------------------------
_scr_ci proc near
push bp
mov ah, cicode ; ask for a keyboard character
int keyboard ; do interrupt
cmp ax, 4a2dh ; test for grey keys
je minus_grey
cmp ax, 4e2bh ; grep plus by default
jne continue
mov al, grey_plus
jmp not_special
minus_grey:
mov al, grey_minus
jmp not_special
continue:
cmp al, 0 ; is low byte equal to zero?
jne not_special ; it's not - must be ascii so return it
mov bx, ds:[offset convert] ; else convert to special key
ci_loop:
cmp byte ptr [bx], 0 ; are we done?
jz got_it ; it's zero - so end routine
cmp ah, byte ptr [bx] ; else does it equal the high byte?
je got_it ; got a hit - finish up
add bx, 2 ; else bump bx
jmp ci_loop
got_it:
inc bx ; get return value from convert
mov al, byte ptr [bx] ; put it in low byte
not_special:
mov ah, 0 ; normal return
pop bp
ret
_scr_ci endp
;---------------------------------------------------------------
; _scr_csts Returns character if available, otherwise zero.
;
; Usage: character = _scr_csts();
;---------------------------------------------------------------
_scr_csts proc near
push bp
mov ah, cstscode
int keyboard
mov ax, 0
jz kbstat
call _scr_ci ; get the coded character
jmp fin
kbstat:
call _get_kbstat
fin:
pop bp
ret
_scr_csts endp
;---------------------------------------------------------------
; _get_kbstat check status of insert key, capslock and alt key
; return special value or zero.
;
; Usage: internal routine used by scr_csts();
;---------------------------------------------------------------
_get_kbstat proc near
push bp
mov ah, kbstatus ; get keyboard status
int keyboard
cmp al, kbset ; set if keyboard status is changed
je return_0 ; if same - return 0
mov kbset, al ; new keyboard toggle - save it
test al, 08h ; test for alt press
jnz alt_pressed
test al, 40h ; test for caps lock on
jnz caps_on
and al, 40h ; reverse bits
test al, 40h ; test if caps lock off
jz caps_off ; if zero then toggled off
return_0:
mov al, 0 ; return 0 - no hits
jmp fin3
alt_pressed:
mov al, Alt_key
jmp fin3
caps_on:
mov al, Caps_Lock_on
jmp fin3
caps_off:
mov al, Caps_Lock_off
fin3:
mov ah, 0
pop bp
ret
_get_kbstat endp
;---------------------------------------------------------------
; _caps_on check status of capslock only
; if on then return CAPSLKON
;
; Usage: if ( caps_on() ) do something
;---------------------------------------------------------------
_caps_on proc near
push bp
mov ah, kbstatus ; get keyboard status
int keyboard
test al, 40h ; test for caps lock on
jnz caps_on1
mov al, 0 ; return 0 - no hits
jmp fin4
caps_on1:
mov al, Caps_Lock_on
fin4:
mov ah, 0
pop bp
ret
_caps_on endp
;---------------------------------------------------------------
; _get_graphic return the next char in buffer - unfiltered
;
; Usage: character = get_graphic();
;---------------------------------------------------------------
_get_graphic proc near
push bp
mov ah, cicode ; ask for a keyboard character
int keyboard ; do interrupt
mov ah, 0 ; normal return
pop bp
ret
_get_graphic endp
;---------------------------------------------------------------
; _scr_cursoff Turns cursor off.
;
; Usage: _scr_cursoff();
;---------------------------------------------------------------
_scr_cursoff proc near
push bp ; save registers
cmp _scr_mode, 4 ; see if graphics
jc text_coff
cmp _scr_mode, 7
jnz no_cur
text_coff:
mov cx, 0f00h ; should turn cursor off
new_cur:
mov ah, curtype ; set a new cursor type
int video
no_cur:
pop bp
ret
_scr_cursoff endp
;---------------------------------------------------------------
; _scr_curson Turns cursor on.
;
; Usage: _scr_curson();
;---------------------------------------------------------------
_scr_curson proc near
push bp
mov cx, 0c0dh ; assume monocrome
cmp _scr_mode, 7 ; true is mono
jz new_cur ; set it
mov cx,0607h ; assume color card in text mode
cmp _scr_mode,4 ; color text is 0 to 3
jc new_cur
pop bp ; do nothing if in graphics mode
ret
_scr_curson endp
;---------------------------------------------------------------
; _scr_aputs Writes a string and attributes to the screen.
; The cursor is moved normally.
; Standard Bios write.
;
; Usage: _scr_aputs( x,y, "Print This", attribute );
;---------------------------------------------------------------
_scr_aputs proc near
push bp
mov bp, sp
mov dx, [bp+4] ; col
mov ax, [bp+6] ; row
mov dh, al
mov bh, _scr_page ; force page
mov ah, setcur ; set cursor location
int video ; dx is cursor location, bh is page
mov si, [bp+8] ; string pointer
mov cx, 1 ; number of characters to write
mov bl, [bp+10] ; attribute
naputs:
cld
lodsb ; next character to write
or al, al ; zero at end
jz eaputs
cmp al, 10 ; look for LF
jnz normal_ap
ap_scroll:
mov bp, sp ; reset pointer to next char
mov [bp+4], si
mov al, 13 ; use tty output to scroll screen
mov ah, wtty
int video ; write cr,lf
mov ah, wtty
mov al, 10
int video
pop bp
jmp _scr_aputs ; start over
normal_ap:
mov bh, _scr_page ; page number
mov ah, writeach ; write char and attr
int video ; write character and attributes
inc dl ; next column
cmp dl, byte ptr crt_cols ; see if wrapping around
jc set_loc
mov dl, 0 ; at start of column
inc dh ; at next row
cmp dh, byte ptr _scr_rows ; see if need a scroll
jc set_loc
jmp ap_scroll ; do a scroll up
set_loc:
mov ah, setcur ; move the cursor
int video
jmp naputs
eaputs:
pop bp
ret
_scr_aputs endp
;-------------------------------------------------------------------
; _scr_putch Write a character to the screen with attribute set.
; standard Bios write
;
; Usage: _scr_putch( character, attribute );
;-------------------------------------------------------------------
_scr_putch proc near
push bp
mov bp, sp
mov ah, readcur ; see where we are
mov bh, _scr_page
int video ; dx is cursor location, bh is page
mov al, [bp+4] ; character to write
mov bl, [bp+6] ; attribute of char
mov bh, _scr_page ; set page number
mov cx, 1 ; write just one char
mov ah, writeach ; write char and attr
int video
inc dl ; move to next column
mov ah, setcur ; move the cursor
int video
pop bp
ret
_scr_putch endp
;--------------------------------------------------------------
;
; The following routines _get_mode, _calc_video, _set_video
; and _scr_putstr were adapted from
; Computer Language Magazine - January 1986
; "Assembly Video Routines for your P.C.", Thomas Webb
;
;--------------------------------------------------------------
;--------------------------------------------------------------
; _get_mode get video mode
;
; Usage: internal subroutine used in _scr_putstr
;--------------------------------------------------------------
_get_mode proc near
push bp
mov ax, 0
mov ah, 15
int 10h
pop bp
ret
_get_mode endp
;----------------------------------------------------------
; _calc_video calculate offset into video buffer
; set begining location and attribute
;
; Usage: internal subroutine used in _scr_putstr
;----------------------------------------------------------
_calc_video proc near
mov ax, byte ptr crt_cols
mul dx
add ax, cx
shl ax, 1
ret
_calc_video endp
;-------------------------------------------------------
; _set_video set video address
;
; Usage: internal subroutine used in _scr_putstr
;-------------------------------------------------------
_set_video proc near
call _get_mode
cmp al, 7h
jne adp_graphics
mov ax, mono_adr
jmp return
adp_graphics:
mov ax, graph_adr
return:
mov vadrs, ax
ret
_set_video endp
;----------------------------------------------------------
; _scr_putstr Writes a string directly to video buffer,
; given the (x,y) location and attribute.
;
; Usage: _scr_putstr(x, y, string, attribute);
;----------------------------------------------------------
_scr_putstr proc near
push es
push bp
mov bp, sp
mov dx, [bp+8] ; get col
mov cx, [bp+6] ; get row
; locate position in video buffer - calc video moved to save a call
mov ax, crt_cols ; calc video routine
mul dx ; moved here
add ax, cx ; to save a call
shl ax, 1
mov di, ax ; return position
mov si, [bp+10] ; get string
mov dh, [bp+12] ; get attribute
mov es, vadrs ; get display address from setup
str_loop:
mov dl, byte ptr [si] ; move the cursor
cmp dl, 0 ; if end then exit
je str_exit
mov es:word ptr [di], dx ; move word into screen display
add di, 2h ; bump string pointer
inc si
jmp str_loop
str_exit:
pop bp
pop es
ret
_scr_putstr endp
;---------------------------------------------------------------
; _scr_aputch Writes a character to the screen with
; attribute set. See _scr_aputs and _scr_co
;
; Usage: _scr_aputch(x,y,char,attribute);
;
; After getting this to work found that it isn't that fast.
; However, it's a good replacement for gotoxy() _scr_putch()
; if you're only writing one char to a specific location.
;
;---------------------------------------------------------------
_scr_aputch proc near
push es
push bp
mov bp, sp
mov dx, [bp+8] ; get col
mov cx, [bp+6] ; get row
call _calc_video ; locate position in video buffer
mov di, ax ; return position
mov dl, [bp+10] ; get char
mov dh, [bp+12] ; get attribute
mov ax, vadrs ; get video address
mov es, ax ; move buffer address to es
mov es:word ptr [di], dx
pop bp
pop es
ret
_scr_aputch endp
;---------------------------------------------------------------
; _scr_sinp Screen input (read character from the screen).
;
; Usage: character = _scr_sinp(); not used
;---------------------------------------------------------------
_scr_sinp proc near
push bp ; save the registers
mov bh, _scr_page
mov ah, readch ; Code to read a character
int video ; al is letter, ah=attributes
or al, al ; zero returned instead of blank in
; graphics mode
jnz ret_ch
mov al, ' '
ret_ch:
mov ah, 0 ; kill the attributes
pop bp
ret
_scr_sinp endp
;---------------------------------------------------------------
; _scr_mark Marks the current character on the screen.
; Used to delimit block.
;
; Usage: _scr_mark(current character) not used
;---------------------------------------------------------------
;mark the passed char, cursor does not advance
_scr_mark proc near
push bp
mov al, 219 ; just write a block character
mov bl, _scr_attr ; normal attributes
mov cx, 1 ; one character
mov bh, _scr_page ; page number
mov ah, writeach ; write char and attr
int video ; write character and attributes
pop bp
ret
_scr_mark endp
_text ends
; That's all!
end
