Technotools/Technotools (Chestnut CD-ROM)(1993).ISO/lang_asm/asm_kit/hercules.asm

Assembly Source File | 1985-12-08 | 13KB | 563 lines

;*********************************************
; *  HERCULES GRAPHICS CARD UTILITY ROUTINES *
; *   graph_mode(),text_mode(),plot(x,y)     *
;*********************************************
;****************************************************************************
;* graph_mode() : puts the hercules graphics card into its graphics mode
;****************************************************************************
;    ******** hercules port addresses ********
INDEX_PORT        equ    03b4H
CTL_PORT        equ    03b8H
CONFIG_PORT        equ    03BFH

;    ******** hercules ctl codes **********
SCRN_ON        equ    8
GRPH        equ    2
TEXT        equ    20H
FULL_MODE    equ    03H

DSEG
gtable        db        35H,2DH,2EH,07H
        db        5BH,02H,57H,57H
        db        02H,03H,00H,00H

ttable        db        61H,50H,52H,0FH
            db        19H,06H,19H,19H
            db        02H,0DH,0BH,0CH

video_page_base_    dw         0,0B000H          ;double-word addr= B000:0000H

            public cursor_x_,cursor_y_,grph_attrib_
cursor_x_            dw        0
cursor_y_            dw        0
grph_attrib_        db        0
CSEG
setmd_:
;        sets mode to graphics or TEXT
;        depending on al
;        si=parameter table
;        cx=number of words to be cleared
;        bx=blank value
        push ds
        push es
        push ax                        ;push mode
        push bx                        ;push blank value
        push cx                        ;push # of words to be cleared

        mov dx,CTL_PORT                ;change mode but without SCRN_ON
        out dx,al

        mov ax,ds                    ;point es:si to parameter table
        mov es,ax

        mov dx,INDEX_PORT
        mov cx,12                    ;12 parameters to be output
        xor ah,ah                    ;starting from reg 0

parms:        mov al,ah
        out dx,al
        inc dx
        lodsb
        out dx,al                    ; output data from table
        inc ah
        dec dx
        loop parms

        pop cx                        ;clear the buffer
        mov ax,0b000h
        cld                            ;setting up for string instruction here

        mov es,ax
        xor di,di
        pop ax
        rep stosw

        mov dx,CTL_PORT                ;turn scrn on, point to page 0
        pop ax
        add al,SCRN_ON
        out dx,al

        pop es
        pop ds
        ret

;****************************************************************************
;* graph_mode() : puts the hercules graphics card into its graphics mode
;****************************************************************************
CSEG
            public graph_mode_
graph_mode_:
    push bp
    push es
    mov al,FULL_MODE
    mov dx,CONFIG_PORT
    out dx,al                                                ;HGC FULL
    mov al,GRPH
    lea si,gtable
    mov bx,0
    mov cx,4000h
    call setmd_
    pop es
    pop bp
    ret

;****************************************************************************
;*  TEXT_mode() : puts the hercules graphics card into TEXT mode
;****************************************************************************

            public TEXT_mode_
TEXT_mode_:
            push bp
            push es
            mov al,TEXT
            lea si,ttable
            mov bx,720h
            mov cx,2000
            call setmd_
            pop es
            pop bp
            ret

;****************************************************************************
;* plot(x,y)  lights the pixel located at coordinates x,y
;*  Hercules graphics card version....
;****************************************************************************
;byte-addr = [2000H + (Ymod4)] + [90*INT(Y/4)] + INT(X/8)
;bit-offset = 7-(Xmod8)
        public plot_
plot_:                            ;scrambles ax,bx,cx,dx,es
        push bp
        mov bp,sp
        mov ax,[bp+6]            ;y in bx
        and ax,0003H            ;(Ymod4) in bx
        mov bx,2000H
        mul bx                    ;(Ymod4)*2000H in ax
        mov bx,ax                ;(Ymod4)*2000H in bx

        mov ax,[bp+6]
        shr ax,1
        shr ax,1                    ;int(y/4) in ax
        mov cx,90                    ;can't multiply by immediate
        mul cx                        ;int(y/4) * 90 in ax
        add bx,ax                    ;[int(y/4) * 90]+[(Ymod4)+2000H] in bx

        mov ax,[bp+4]                ;x in ax
        shr ax,1
        shr ax,1
        shr ax,1                    ;int(x/8) in bx
        add ax,bx                ;whole byte offset address in ax
        les bx,video_page_base_    ;es:bx points to video base
        add bx,ax                ;entire address in es:bx
        mov ax,[bp+4]            ;X in ax
        and ax,0000000000000111B        ;Xmod8 in ax
        mov cl,al                ;Xmod8 becomes shift count
        mov al,10000000B        ;start from the top
        shr al,cl                ;bit pos is now in al, addr in es:bx

        or es:[bx],al            ;this one does the deed!

        pop bp
        ret

;*****************************************
;* init_page_1() copies page 0 into page 1
;*****************************************
            public init_page_1_
init_page_1_:
        push bp
        push es
        push si
        push di
        push ds
        mov ax,0B000H
        mov es,ax                ;es and ds both point to video ram
        mov ds,ax                ;no working variables... might have to move this one
        mov si,0                ;source is page 1
        mov di,8000H            ;dest is page 2
        mov cx,8000H            ;xfr 8000 bytes(one graphics page)
        cld                        ;going up...
        rep movsb                ;do it to it!
        pop ds
        pop di
        pop si
        pop es
        pop bp
        ret

;*****************************************
;* init_page_0() copies page 1 into page 0
;*****************************************
            public init_page_0_
init_page_0_:
        push bp
        push es
        push si
        push di
        push ds
        mov ax,0B000H
        mov es,ax                ;es and ds both point to video ram
        mov ds,ax                ;no working variables... might have to move this one
        mov si,8000H                ;source is page 1
        mov di,0            ;dest is page 0
        mov cx,4000H            ;xfr 8000 bytes(one graphics page)
        cld                        ;going up...
        rep movsw                ;do it to it!
        pop ds
        pop di
        pop si
        pop es
        pop bp
        ret

;*******************************************************************
;* graphics_cls(page) clears the screen when it's in graphics mode *
;*******************************************************************
;1  process graphics_cls
        public graphics_cls_
graphics_cls_:

        push bp
        mov bp,sp            ;page# in [bp+4]

   ;2  if we need to clear page 0
        mov ax,[bp+4]
        or ax,ax
        jnz graphics_cls_1

      ;3  point at page 0
        mov di,0000H

   ;2  else(we need to clear page 1)
        jmp graphics_cls_2
graphics_cls_1:

      ;3  point at page 1
        mov di,8000H

   ;2  endif(page 0 or 1?)
graphics_cls_2:

   ;2  set up the rest of the block load
        mov ax,0B000H
        mov es,ax            ;video base addr
        mov cx,8000H            ;length of page
        mov ax,0
        cld                ;load UP
        rep stosb

   ;2  zero out the graphics cursor
        mov ax,0
        mov cursor_x_,ax
        mov cursor_y_,ax

;1  endprocess graphics_cls
        pop bp
        ret

;/********************************************************/
; Hercules graphic text drawing routines
;/********************************************************/
include "hercfont.a"

y_table_:                            ;tells us the starting y offset for a char
                                    ;it has one entry for each of the 27 rows
        dw 0000H                    ;letter row 0
        dw 210EH                    ;letter row 1
        dw 421CH                    ;letter row 2
        dw 632AH                    ;letter row 3
        dw 0492H                    ;letter row 4
        dw 25A0H                    ;letter row 5
        dw 46AEH                    ;letter row 6
        dw 67BCH                    ;letter row 7
        dw 0924H                    ;letter row 8
        dw 2A32H                    ;letter row 9
        dw 4B40H                    ;letter row 10
        dw 6C4EH                    ;letter row 11
        dw 0DB6H                    ;letter row 12
        dw 2EC4H                    ;letter row 13
        dw 4FD2H                    ;letter row 14
        dw 70E0H                    ;letter row 15
        dw 1248H                    ;letter row 16
        dw 3356H                    ;letter row 17
        dw 5464H                    ;letter row 18
        dw 7572H                    ;letter row 19
        dw 16DAH                    ;letter row 20
        dw 37E8H                    ;letter row 21
        dw 58F6H                    ;letter row 22
        dw 7A04H                    ;letter row 23
        dw 1B6CH                    ;letter row 24
        dw 3C7AH                    ;letter row 25


CSEG
;*******************************************
;* set plot_tty_cursor(x,y)
;*******************************************
        public set_plot_tty_cursor_
set_plot_tty_cursor_:
        push bp
        mov bp,sp
        mov ax,[bp+4]
        mov cursor_x_,ax
        mov ax,[bp+6]
        mov cursor_y_,ax
        pop bp
        ret

;*******************************************
;1  process plot_char_tty(ascii_char)
        public plot_char_tty_
plot_char_tty_:
        push bp
        mov bp,sp

   ;2  if this is not a control char
        mov al,[bp+4]
        and al,07FH
        cmp al,20H
        jc plot_char_tty_1

      ;3  output char at current cursor position
        mov al,[bp+4]
        push ax
        mov ax,cursor_y_
        push ax
        mov ax,cursor_x_
        push ax
        call plot_char_
        add sp,6

      ;3  increment cursor position
        call increment_cursor_

   ;2  else (ctl char)
        jmp plot_char_tty_2
plot_char_tty_1:

      ;3  if the char is a <CR>
            mov al,[bp+4]
            cmp al,0Dh
            jnz plot_char_tty_3

         ;4  cursor_x_ = 0
            mov ax,0
            mov cursor_x_,ax

      ;3  else if the char is <LF>
            jmp plot_char_tty_4
plot_char_tty_3:
            cmp al,0AH
            jnz plot_char_tty_4

         ;4  cursor_y_++
            mov ax,cursor_y_
            inc ax
            mov cursor_y_,ax
            cmp ax,26                        ;line at bottom will roll over to
            jc plot_char_tty_5                ;top
            mov ax,0
            mov cursor_y_,ax
plot_char_tty_5:

      ;3  endelseif
plot_char_tty_4:

   ;2  endif(ctl char?)
plot_char_tty_2:

;1  endprocess plot_char_tty
        pop bp
        ret

;************************************
;* plot_char(x,y,ascii_char)
;* x can be from 0 thru 89                [bp+4] = x,[bp+6]=y,[bp+8]=ascii_char
;* y can be from 0 thru 25
;************************************
;* sets global cursor_x and cursor_y to where it's own parameters
;we have defined font patterns for ascii 20H thru 5AH
;1  process plot_char            ;destroys contents of bx,si,ax,es
        public plot_char_
plot_char_:
        push bp
        mov bp,sp

   ;2  convert the ascii char to a table pointer
        mov al,[bp+8]
        push ax
        call convert_ascii_
        add sp,2
        mov [bp+8],ax                ;table ptr in [bp+8]

   ;2  point to the beginning of the char in video ram
        les bx,video_page_base_            ;es:bx point to video card base
        mov bx,[bp+6]            ;y in bx
        add bx,bx                ;two bytes per table entry
        mov ax,y_table_[bx]        ;address in ax
        add ax,[bp+4]            ;add in x
        mov bx,ax        ;es:bx now point to video board char position

        mov si,[bp+8]        ;ds:si points to table
        mov al,[si]        ;first byte in al
        xor al,grph_attrib_        ;reverse video?
        mov es:[bx],al        ;out to video

   ;2  repeat
        mov cx,9
plot_char_1:

      ;3 increment table pointer
        inc si

      ;3  increment video ram pointer
        add bx,2000H                        ;point to next bank
        cmp bx,8000H                        ;do we roll over

        jc plot_char_2                        ;pop over this next if 8000H bigger
        add bx,5AH
        and bx,1FFFH                        ;and referance back down to 1st bank
plot_char_2:

      ;3  move char pattern out to video ram
        mov al,[si]
        xor al,grph_attrib_                    ;reverse video if grph_attrib=ff
        mov es:[bx],al

   ;2  9 times
        loop plot_char_1

;1 endprocess plot_char
        pop bp
        ret

;1  process convert_ascii
        public convert_ascii_
convert_ascii_:
        push bp
        mov bp,sp                    ;input parameter = [bp+4]

   ;2  make input into 7-bit ascii
        mov al,[bp+4]
        and al,07FH
        mov [bp+4],al

   ;2  if input > bottom-ot-ascii-table -1
        cmp al,17H
        jc convert_ascii_1

      ;3  if input < end of ascii table + 1
        mov al,[bp+4]
        sub al,7BH
        jnc convert_ascii_3

         ;4 just leave it unmolested

      ;3  else (input > 5BH)
        jmp convert_ascii_4
convert_ascii_3:

         ;4  return space
        mov byte [bp+4],20H

      ;3  endif(input < 5bH?)
convert_ascii_4:

   ;2  else (input not greater than 1FH)
        jmp convert_ascii_2
convert_ascii_1:

      ;2 return space
        mov byte [bp+4],20H

   ;2  endif
convert_ascii_2:

   ;2  get the output parameter
        mov ax,[bp+4]                ;index into table
        sub ax,18H                    ;- offset(18H is first table entry)
        mov bx,10                    ;times bytes/entry
        mul bx                        ;answer still fits in ax
        add ax,offset ascii_table_

;1  endprocess convert_ascii
        pop bp
        ret

;*******************************************
;1  process plot_string(string)
        public plot_string_
plot_string_:
        push bp
        mov bp,sp

   ;2  get parameter
        mov bx,[bp+4]

   ;2  get first char
        mov al,[bx]

   ;2  repeat
plot_string_1:

      ;3  plot_char_tty(char)
        push bx
        push ax
        call plot_char_tty_
        add sp,2
        pop bx

      ;3  get next char
        inc bx
        mov al,[bx]

   ;2  until character=0
        or al,al
        jnz plot_string_1

;1  endprocess plot_string
        pop bp
        ret

;*******************************************
;1  process increment_cursor
        public increment_cursor_
increment_cursor_:
        push bp

   ;2  increment cursor_x_ position
        mov ax,cursor_x_
        inc ax                                ;cursor_x_+1 in ax
        mov cursor_x_,ax

   ;2  if cursor_x_ got to 80
        cmp ax,80
        jc increment_cursor_1

      ;3  cursor_x_ = 0
        mov ax,0
        mov cursor_x_,ax

      ;3  cursor_y_++
        mov ax,cursor_y_
        inc ax
        mov cursor_y_,ax

      ;3  if cursor_y_ = 26
        cmp ax,26
        jnz increment_cursor_2

         ;4  cursor_y_ = 0
        mov ax,0
        mov cursor_y_,ax

      ;3  endif(cursor_y_= 26?)
increment_cursor_2:

   ;2  endif(cursor_y_= 80?)
increment_cursor_1:

;1  endprocess increment_cursor_
        pop bp
        ret