The World of Computer Software/The World of Computer Software.iso/pcc12d.zip/PCIO.A

Text File | 1988-11-29 | 13KB | 577 lines

;    PCIO.A    --    Screen and keyboard interface routines for the PC


        dseg
;    In this implementation, all special and function keys are translated
;    to the following values.

;/* control key translations */
up_char        equ    30
down_char    equ    31
left_char    equ    29
right_char    equ    28
bol_char    equ    200
eol_char    equ    201
pageup_char    equ    202
pagedown_char    equ    203
bof_char    equ    204
eof_char    equ    205
Ins_char    equ    206
Del_char    equ    207
NextWord_char    equ    208
PrevWord_char    equ    209

M1        equ    210
M2        equ    211
M3        equ    212
M4        equ    213
M5        equ    214
M6        equ    215
M7        equ    216
M8        equ    217
M9        equ    218
M10        equ    219
;    the table that is used to make the translation

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    77H, bof_char
        db    75H, eof_char
        db    82, Ins_char
        db    83, Del_char
        db    115, PrevWord_char
        db    116, NextWord_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



;    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        ;code for keyboard status




;    caution: must change column number if 40 column mode

crt_cols    equ    80

;    variables available to a C88 program

        public    scr_cols_, scr_rows_, scr_scrollup_, scr_scrolldown_
        public    scr_mode_,scr_page_,scr_attr_,scr_window_top_

scr_cols_:    dw    crt_cols    ;current number of columns

;    note- make 25 for ms-dos and 24 for cp/m as cp/m steals the bottom
;    line.
scr_rows_:    dw    25        ;current number of rows
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    2        ;first line to scroll

;    variables needed by SEE. Not used here.
scr_scrollup_:    db    0        ;zero if scrollup leaves top line alone
scr_scrolldown_:db    0        ;zero if scroll down supported



        cseg

;    SCR_SETUP_    scr_setup must be called before any use of any
;            other routine unless the starting mode is 80X25
;            character mode (3,4 or 7). Must be called for monocrome
;            (mode 7) for scr_curson to set a proper cursor.

;            Usage:    scr_setup();

        public    scr_setup_
scr_setup_:    push    bp
        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
        pop    bp
        ret


;    SCR_TERM_        do any required termination.

;                Usage:  scr_term();

    public    scr_term_
scr_term_:
    ret





;    SCR_SETMODE_        set a new screen mode

;                Usage:    scr_setmode(new mode);

        public    scr_setmode_
scr_setmode_:    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_ROWCOL_        sets cursor at any location.

;                Usage:    scr_rowcol(new row, new column);

        public    scr_rowcol_
scr_rowcol_:                ; move cursor to x,y
        push    bp        ; save from bios
        mov    bp,sp
        mov    dx,[bp+6]    ; column
        mov    ax,[bp+4]    ; 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_CLR_        clear entire screen

;                Usage:    scr_clr();

        public    scr_clr_
scr_clr_:                ; clear screen


        push    bp        ;save from video call
        mov    al,0        ;ask for a clear window
        xor    cx,cx        ;start at 0,0
        mov    dh,byte scr_rows_;last line
        dec    dh
        mov    dl,byte 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_CLRL_        clear rest of line.

;                Usage:        scr_clrl();

        public    scr_clrl_
scr_clrl_:                ; clear rest of line
        push    bp
        mov    bh,scr_page_
        mov    ah,readcur    ;see where we are
        int    video
        mov    cl,byte 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_CLS_        clear rest of screen.

;                Usage:    scr_cls();

        public    scr_cls_
scr_cls_:                    ; clear rest of screen
        push    bp
        call    scr_clrl_    ;clear rest of line
        mov    ah,readcur    ;see where we are
        mov    bh,scr_page_
        int    video
        mov    al,0        ;ask for a clear window
        mov    ch,dh        ;current row
        inc    ch        ;+1
        cmp    ch,byte scr_rows_;see if in last line
        jz    cleared        ;all done
        mov    cl,0        ;first column
        mov    dh,byte scr_rows_;24 is the last line
        dec    dh
        mov    dl,byte 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:    pop    bp

        ret



;    SCR_SCUP_        scroll text up leaving top lines alone.

;                Usage:    scr_scup();

        public    scr_scup_
scr_scup_:            ; scroll last line, screen from line
                ; scr_windor_top to end
        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_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);

        public    scr_scrup_
scr_scrup_:    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_SCDN_        scroll all but the top lines down one.

;                Usage:    scr_scdn();

        public    scr_scdn_
scr_scdn_:
        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_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);

        public    scr_scrdn_
scr_scrdn_:    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_CO_            write a character to the screen. this
;                routine increments the cursor position
;                after writing. normal C88 puts and printf
;                statements can also be used to write to the
;                screen.

;                Usage:    scr_co_(character);

        public    scr_co_
scr_co_:                    ; standard console output
        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_CI_            keyboard input. function and soft keys are
;                translated. see equates for values.

;                Usage:    character = scr_ci();

        public    scr_ci_
scr_ci_:                ;return the next character
                    ; translate if necessary
        push    bp
        mov    ah,cicode    ;ask for a keyboard character
        int    keyboard
        cmp    al,0
        jne    not_special
        mov    bx, offset convert    ; convert special key
ci_loop:
        cmp    byte[bx],0
        jz    got_it
        cmp    ah, byte[bx]
        je    got_it
        add    bx,2
        jmp    ci_loop
got_it:        inc    bx
        mov    al,[bx]
        mov    ah,0
        pop    bp
        ret
not_special:    mov    ah,0
        pop    bp
        ret


;    SCR_CSTS_        return character if any available. otherwise
;                return zero.

;                Usage:    character = scr_csts();

        public    scr_csts_
scr_csts_:                ;return coded character if any available
        push    bp
        mov    ah,cstscode
        int    keyboard
        mov    ax,0
        jz    csts_over
        call    scr_ci_        ;get the coded character
csts_over:    pop    bp
        ret


;    SCR_SET_CURSOR_        does nothing. needed by SEE.


        public    scr_set_cursor_
scr_set_cursor_:            ; set the visible cursor to the
                    ; current position
        ret



;    SCR_SINP_        screen input (read character from the screen).

;                Usage:    character = scr_sinp();

        public    scr_sinp_
scr_sinp_:
        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_CURSOFF_        turn cursor off.

;                Usage:    scr_cursoff();

        public    scr_cursoff_
scr_cursoff_:
        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_CURSON_        turn cursor back on.

;                Usage:    scr_curson();

        public    scr_curson_
scr_curson_:
        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_MARK  --  mark the current character on the screen.
;              Used to delimit block areas in SEE. Just write
;              an X or something if reverse video is not available.
;              Usage:   scr_mark(current character);

    public    scr_mark_
scr_mark_:                    ; mark the passed char,
                        ; cursor does not advance
        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


;    the following routine is not used by either SEE or D88.


;    SCR_APUTS_        write a string and attributes to the screen.
;                the cursor is moved normally

;                Usage:  acr_aputs("Print This",attribute);
;                attribute is BRGBIRGB
;                         | | | |
;                         | | | color for letter. 7 is white
;                         | | intensity for letter
;                         | color for background. 0 is black
;                         blinking

        public scr_aputs_
scr_aputs_:
        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    si,[bp+4]    ;string pointer
        mov    cx,1        ;number of characters to write
        mov    bl,[bp+6]    ;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,crt_cols    ;see if wrapping around
        jc    set_loc
        mov    dl,0        ;at start of column
        inc    dh        ;at next row
        cmp    dh,byte 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