****************************** TEXT MODE ******************************* ASM32 Text mode video subroutines (C) Copyright 1993 - 1995 Douglas Herr All rights reserved ASM32 subroutines write directly to the video memory buffer, except where noted. ASM32 detects the default display type and screen dimensions. ASM32 assumes that CGA equipment requires "snow" control and behaves accordingly. EGA32.LIB, provided with registration, does not include CGA "snow" control and is somewhat faster and more compact. EGA32.LIB will be best for most 32-bit PCs, but there are many 386SX and 386DX computers which were upgraded from 16-bit processors with a variety of video systems. For this reason ASM32 includes support for a variety of video systems. Multiple pages of video memory are available except with MDA video adapters. Pages supported by ASM32 are shown below: video system screen size ASM32 support BIOS support ------------- ----------- -------------- --------------- MDA 80 x 25 page 0 page 0 CGA, MCGA 80 x 25 pages 0 - 3 pages 0 - 3 CGA, EGA, VGA 40 x 25 pages 0 - 7 pages 0 - 7 EGA, VGA 80 x 25 pages 0 - 7 pages 0 - 7 EGA 80 x 43 pages 0 - 3 pages 0 - 3 VGA 80 x 50 pages 0 - 3 pages 0 - 3 SEGA, SVGA 132 x 25 pages 0 - 3 pages 0 - 3 SEGA, SVGA 132 x 43 pages 0 & 1 pages 0 & 1 HGC, HGC+, InC 80 x 25 pages 0 - 15 page 0 HGC+, InC 90 x 25 pages 0 - 13 page 0 HGC+, InC 80 x 43 page 0 page 0 HGC+, InC 90 x 43 page 0 page 0 ASM32 subroutines assume that rows are the vertical dimension and columns are the horizontal dimension of a text-mode screen. The upper left corner of the screen is at row=0 and col=0 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ANSICOLOR: determines color attribute used by ANSI device driver. See also IsANSI. Source: anscolor.asm Call with: no parameters Returns: AH = color attribute Uses: EAX Example: call ansicolor ; get ANSI screen color in AH 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� BLINK: enable or disable blinking attriutes disable or enable bright background attributes Source: blink.asm Call with: AL = 1 for blinking attributes/no bright background attributes AL = 0 for no blinking attributes/bright background attributes Returns: nothing Uses: nothing; all registers and flags are saved Supports: All ASM32 text modes Example: include codeseg.inc . . . mov al,0 call blink ; turn blinking attributes into bright ; background attributes . . . mov al,1 call blink ; turn bright background attributes into ; blinking attributes 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� CRTINFO: central control for ASM32 Text subroutines; determines active video system, screen size, page offset. Source: crtinfo.asm Call with: AH = 0 for page 0 information AH = -1 to calculate active page address Returns: AL = screen rows CH = screen columns ES:[EBX] = video buffer address DX = 3DAh if CGA, 0 if not CGA DX is used to monitor screen retrace, to avoid "snow" on older CGA systems. Uses: ES, AX, EBX, CX, DX, flags Supports: all ASM32 text modes 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� CURSORCOLOR: set cursor color and enable color palette (InColor only) Source: curscolor.asm ($herc.asm) Call with: AH = color attribute (1 - 15) Returns: if CF = 0, no error if CF = 1, InColor card not installed Uses: Carry Flag Supports: Hercules InColor card only Example: extrn cursorcolor:proc .code . . . mov ah,14 ; bright yellow cursor call cursorcolor ; enable InColor palette, set cursor color 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� CURSOROFF: make hardware cursor invisible at present location Source: cursor.asm Call with: no parameters Returns: nothing Uses: nothing Supports: CGA, MDA, HGC, HGC+, InC, EGA, VGA, SEGA, SVGA: text mode Example: call cursoroff 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� CURSORON: move cursor to (row, col) and update cursor shape Cursor shape is underscore if INSERT is off, larger block if INSERT is on. See also UCursorON. Source: cursor.asm (crtinfo.asm) Call with: DH = row offset from top of screen DL = column offset from left side Returns: nothing Uses: EAX Supports: CGA, MCGA, MDA, HGC, HGC+, InC, EGA, SEGA, SVGA, VGA: text mode Example: mov dh,row ; vertical coordinate on text screen mov dl,column ; horizontal coordinate call cursoron 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� GETSCREEN: save a screen page to a memory buffer PUTSCREEN: copy a saved screen page to the video buffer Source: screen.asm (crtinfo.asm, $wcopy.asm) Call with: ESI pointing to memory buffer Returns: nothing Uses: nothing; all flags and registers are saved Supports: All ASM32 text modes; includes CGA snow control Example: see ScreenBytes for example 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� HSCROLL: scroll a portion of the screen left or right. Source: hscroll.asm ($wdata.asm, $wcopy.asm, a$putw.asm) Call with: EBX pointing to corner coordinates AH = color attribute for cleared columns ECX = number of columns to scroll scrolls left if ECX > 0, scrolls right if ECX < 0 clears area if ECX = 0 Returns: nothing Uses: nothing Supports: All ASM32 text modes; includes CGA snow control Example: include dataseg.inc ; data wdata dw 10 ; row0 dw 10 ; column0 dw 20 ; row1 dw 40 ; column1 @curseg ends include codeseg.inc ; code . . . lea ebx,wdata ; EBX points to window coordinates mov ah,color ; AH = color attribute for cleared columns mov ecx,columns ; COLUMNS defined elsewhere call hscroll ; to clear entire window, columns = 0 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� PAINT: change all color attributes on a text-mode screen without re-printing the text Source: paint.asm (crtinfo.asm, $paint.asm) Call with: AH = new color attribute Returns: nothing Uses: nothing Supports: All ASM32 text modes; includes CGA snow control Example: mov ah,newcolor call paint 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� RECOLOR: change selected color attributes on a text-mode screen Replaces oldcolor attribute with newcolor, without re-printing the text. Source: recolor.asm (crtinfo.asm, $recolor.asm) Call with: AL = color to replace AH = new color attribute Returns: nothing Uses: nothing Supports: All ASM32 text modes; includes CGA snow control Example: mov al,oldcolor mov ah,newcolor call recolor 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� SCREENBYTES: calculate bytes required to save screen page Used with GetScreen and PutScreen. Source: scrbytes.asm (crtinfo.asm) Call with: no parameters Returns: EAX = number of bytes required Uses: EAX Example: include model.inc include dataseg.inc saved_pointer dd ? @curseg ends include codeseg.inc . . . call screenbytes mov ebx,eax sys GetMemNear jc drat ; jump if error control needed mov saved_pointer,esi call getscreen ; save the screen . . . mov esi,saved_pointer call putscreen ; restore the initial screen 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� SHOWTPAGE: change video page shown on screen Source: tpage.asm (crtinfo.asm, $herc.asm) Call with: BL = page number Returns: AX = error code 0 = no error -1 = bad page number Uses: AX Supports: All ASM32 text modes (except MDA equipment, some RamFont modes) Example: mov bl,1 ; show page 1 call showtpage 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� SNOWOFF: disables CGA snow control SNOWON: enables CGA snow control (ASM32 default) Source: crtinfo.asm Call with: no parameters Returns: nothing Uses: no registers or flags Example: extrn snowoff:near extrn getcrt:near include codeseg.inc ; code . . . call getcrt cmp ax,2 ; ASM32 doesn't disable snow control ; on MCGA systems jne short continue call snowoff ; MCGA doesn't need snow control continue: 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� STR2VBUF: copies a string to video memory buffer, with selected color attribute; includes snow control for CGA systems Source: str2vbuf.asm Call with: ECX = maximum number of characters to print (will also stop at NUL character) DX = 0 to disable snow control = 3DAh to enable CGA snow control (if DX = 3DAh on systems without a color monitor, the computer will jam up solid) ESI points to first character of string ES:[EDI] points to video buffer AH = color attribute DF = 0 (clear direction flag with CLD) Returns: EDI points to video buffer following string if AL = 0 ESI points to byte following string's NUL terminator if AL <> 0 ESI points to next byte in string after the last one printed on the screen Uses: AL, ECX, EDI, ESI, flags 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TCENTER: prints a string on the screen, centered horizontally TNCENTER: prints ECX bytes of a string on the screen, centered horizontally Source: tcenter.asm (crtinfo.asm, str2vbuf.asm, strlen.asm) Call with: ESI pointing to the string DH = row to print the string on AH = color attribute (tncenter only) ECX = number of bytes to print Returns: nothing Uses: nothing Supports: all ASM32 text modes; includes CGA snow control Example: lea esi,string ; ESI points to the string mov dh,row mov ah,attr ; color attribute call tcenter ; center the string on row in DH 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TCLEAR: clear a text-mode screen with specified color attribute Source: tclear.asm (crtinfo.asm, a$putw.asm) Call with: AH = color attribute Returns: nothing Uses: AL Supports: all ASM32 text modes; includes CGA snow control Example: mov ah,color call tclear 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TCOPY: copies one page of text-mode video memory to another page Source: tcopy.asm (crtinfo.asm, tpage.asm, $herc.asm) Call with: BH = frompage, BL = topage Returns: if CF = 0, all OK if CF = 1 and AH = -1, frompage number is out-of-bounds if CF = 1 and AL = -1, topage number is out-of-bounds Uses: EAX, CF Supports: all ASM32 text modes, pages 0 - 15; includes CGA snow control Example: mov bh,0 ; frompage mov bl,1 ; copy from page 0 to page 1 call tcopy jc oops ; oh yuck - an MDA 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TFILL: fill a text-mode screen with specified character and color Source: tclear.asm (crtinfo.asm, a$putw.asm) Call with: AH = color attribute, AL = fill character Returns: nothing Uses: nothing Supports: all ASM32 text modes; includes CGA snow control Example: mov ah,color mov al,char ; AL = character to fill screen call tfill 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TGETCHR: read character and attribute from text screen Source: tgetchr.asm (crtinfo.asm) Call with: DH = screen row DL = screen column Returns: AH = color attribute AL = ASCII character code Supports: all ASM32 text modes; includes CGA snow control Example: extrn tgetchr:near include dataseg.inc ; data position label word column db 13 row db 18 @curseg ends include codeseg.inc ; code . . . mov dx,position call tgetchr ; returns with AL = ASCII character code ; and with AH = color attribute 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TLOAD: loads a screen image disk file saved by TSave Source: tload.asm (crtinfo.asm) Call with: EDX = address of ASCIIZ filename in low memory Returns: if CF = 1, AX = MS-DOS file I/O error code if CF = 0, no error Uses: EAX, CF Supports: all ASM32 text modes; no CGA snow control see also TSave Example: extrn tload:proc include dataseg.inc ; data filename db 'tscreen.bin',0 @curseg ends include codeseg.inc ; code . . . lea edx,filename call tload 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TPAGE: changes active page and shows new active page Source: tpage.asm (crtinfo.asm, $herc.asm) Call with: BL = page number for ASM32 subroutines writing directly to video memory. See also UseTPage and ShowTPage. ASM32's active page is not affected by INT 10h mode changes. Page -1 may be used on two-monitor systems, directs ASM32 video output to Monochrome screen (except cursor). Returns: AX = error code if AX = 0, no error if AX = -1, bad page number if AX = 1, page may be written to but cannot be shown Uses: AX Supports: text-mode screens, all row/column configurations Example: mov bl,page call tpage 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TPRINT: print ASCIIZ string directly to video buffer. String must be terminated by a NUL character. The string may be in either low memory or high memory. Source: tprint.asm (crtinfo.asm, str2vbuf.asm) Call with: ESI pointing to the string DH = screen row, DL = screen column AH = color attribute Returns: ECX = bytes printed Uses: ECX Supports: all ASM32 text modes; includes CGA snow control Example: lea esi,string ; ESI points to the string mov dh,row mov dl,column mov ah,attr ; color attribute call tprint 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TPRINTCE: prints an ASCIIZ string on the screen at specified position and specified color, and clears from the end of the string to the right edge of the screen. The string may be in either low memory or high memory. Source: tprintce.asm (crtinfo.asm, str2vbuf.asm, a$putw.asm) Call with: ESI pointing to the string DH = screen row, DL = screen column AH = color attribute Returns: ECX = bytes ptrinted Uses: ECX Supports: all ASM32 text modes; includes CGA snow control Example: lea esi,string ; ESI points to the string mov dh,row mov dl,column mov ah,attr ; color attribute call tprintce 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TPRINTL: print ASCIIZ string directly to video buffer, lower case Source: tprintl.asm (crtinfo.asm) TPRINTU: print ASCIIZ string directly to video buffer, upper case Source: tprintu.asm (crtinfo.asm) String must be terminated by a NUL character. Similar to TPrint, but characters a - z are TPrinted as upper case A - Z (TPrintU) or characters A - Z are TPrinted as lower case a - z (TPrintL). The string itself is not altered. Call with: ESI pointing to the string DH = screen row, DL = screen column, AH = color attribute Returns: nothing Uses: nothing Supports: all ASM32 text modes; includes CGA snow control Example: lea esi,string ; ESI points to the string mov dh,row mov dl,column mov ah,attr ; color attribute call tprintu 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TPUTCHR: write character and attribute to screen Source: tputchr.asm (crtinfo.asm) Call with: AL = ASCII character AH = color attribute DH = screen row DL = screen column Returns: nothing Uses: nothing Supports: all ASM32 text modes; includes CGA snow control Example: extrn tputchr:near include dataseg.inc ; data position label word column db 13 row db 18 color db 32 ; white on blue background @curseg ends include codeseg.inc ; code . . . mov dx,position mov ah,color mov al,'#' ; character to write call tgetchr ; returns with AL = ASCII character code ; and with AH = color attribute 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� TSAVE: saves a screen image as a disk file; does not compress the image Source: tsave.asm (crtinfo.asm) Call with: EDX = address of ASCIIZ filename in low memory Returns: if CF = 1, AX = MS-DOS file I/O error code if CF = 0, no error Uses: EAX, CF Supports: All ASM32 text modes; no CGA snow control see also TLOAD Example: extrn tsave:proc include dataseg.inc ; data filename db 'tscreen.bin',0 @curseg ends include codeseg.inc ; code . . . lea edx,filename call tsave 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� UCURSORON: similar to CursorON, but the underscore cursor is used regardles of the state of the INSERT toggle. See also CursorON. Source: cursor.asm (crtinfo.asm) Call with: DH = row offset from top of screen DL = column offset from left side Returns: nothing Uses: AX Supports: text mode, all pages, all row/column configurations Example: mov dh,row mov dl,col call ucursoron 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� USETPAGE: establish ASM32's active page Source: tpage.asm (crtinfo.asm, $herc.asm) Call with: BL = page number ASM32 text-mode subroutines can be directed to any video page. ASM32's active page is not affected by INT 10h mode changes. UseTPage does not change the page shown on the screen. See also TPage and ShowTPage. If newpage = -1, ASM32 video output is directed to a Monochrome screen Returns: AX = error code if AX = -1, bad page number Uses: AX, ES Supports: All ASM32 text modes Example: mov bl,page call usetpage 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� VSCROLL: scroll a portion of the screen up or down. Source: vscroll.asm ($wdata.asm, $wcopy.asm, a$putw.asm) Call with: EBX pointing to corners of scroll area AH = color attribute, ECX = number of rows to scroll Scrolls up if ECX > 0, scrolls down if ECX < 0, clears area if ECX = 0 Returns: nothing Uses: nothing Supports: all ASM32 text modes; includes CGA snow control Example: include dataseg.inc ; data wdata dw 10 ; row0 dw 10 ; column0 ; (row0, column0) = upper left corner dw 20 ; row1 dw 40 ; column1 ; (row1, column1) = lower right corner @curseg ends include codeseg.inc ; code . . . lea ebx,wdata ; EBX points to window coordinates mov ah,color mov ecx,3 ; scroll up 3 rows call vscroll 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� WCLEAR: clear a rectangular portion of a text-mode screen Source: wclear.asm ($wdata.asm, crtinfo.asm, a$putw.asm) Call with: EBX pointing to box corner data AH = color attribute Returns: nothing Uses: AL, flags Supports: all ASM32 text modes; includes CGA snow control Example: include dataseg.inc ; data wdata dw 10 ; row0 dw 10 ; column0 dw 20 ; row1 dw 40 ; column1 @curseg ends include codeseg.inc ; code . . . lea ebx,wdata ; EBX points to window coordinates mov ah,color call wclear ; clear a box on the screen with corners ; at (row0, column0), (row1, column0), ; (row0, column1) and (row1, column1) 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� WFILL: fill a rectangular protion of a text-mode screen with specified character and attribute; variation of WClear Source: wclear.asm ($wdata.asm, crtinfo.asm, a$putw.asm) Call with: EBX pointing to box corner data AH = color attribute AL = fill character Returns: nothing Uses: flags Supports: all ASM32 text modes; includes CGA snow control Example: include dataseg.inc ; data wdata dw 10 ; row0: top of fill area dw 10 ; column0: left side of fill area dw 20 ; row1: last row of fill area dw 40 ; column1: right side of fill area @curseg ends include codeseg.inc ; code . . . lea ebx,wdata ; EBX points to window coordinates mov ah,color mov al,'�' ; use ASCII 254 to fill call wfill ; fill a box on the screen with corners ; at (row0, column0), (row1, column0), ; (row0, column1) and (row1, column1) 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� WFRAME: draw a box on a text-mode screen Source: wframe.asm (a$wdata.asm, a$putw.asm, crtinfo.asm) Call with: EBX pointing to box corner data AH = color attribute AL = box character box character is the character associated with an ASCII code if AL = 0, a single line is used if AL = -1, a double line is drawn Returns: nothing Uses: nothing Supports: all ASM32 text modes; includes CGA snow control Example: include dataseg.inc ; data wdata dw 10 ; row0 dw 10 ; column0 dw 20 ; row1 dw 40 ; column1 @curseg ends include codeseg.inc ; code . . . lea ebx,wdata ; EBX points to window coordinates mov ah,color mov al,'�' ; use ASCII 254 for boundary call wframe ; draw a box on the screen with corners ; at (row0, column0), (row1, column0), ; (row0, column1) and (row1, column1) 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� WSIZE: calculate the memory required to save a screen window Source: wsize.asm Call with: EBX pointing to row & column coordinates The row and column coordinates define the corners of the window. Returns: EAX = bytes required Uses: EAX Supports: All ASM32 text modes Example: include dataseg.inc ; data wdata dw 10 ; row0 dw 10 ; column0 dw 20 ; row1 dw 40 ; column1 @curseg ends include codeseg.inc ; code . . . lea ebx,wdata ; EBX points to window coordinates call wsize ; returns EAX = bytes required mov ebx,eax sys GetMemNear jc oh_no ; big problem if no space! 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� WPAINT: replace all color attributes in a window of the screen Source: wpaint.asm ($wdata.asm, crtinfo.asm, $paint.asm) Call with: EBX pointing to window coordinates AH = new color attribute Returns: nothing Uses: nothing; all registers and flags are saved Supports: all ASM32 text modes; includes CGA snow control Example: include dataseg.inc ; data wdata dw 10 ; row0 dw 10 ; column0 dw 20 ; row1 dw 40 ; column1 @curseg ends include codeseg.inc ; code . . . lea ebx,wdata ; EBX points to window coordinates mov ah,color ; AH = new color attribute call wpaint 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� WPRINT: print ASCIIZ string directly to the video buffer in a window of screen, with word wrap. String must be terminated by a NUL character. WPrint clears any portion of the window not occupied by the string. Source: WPRINT.ASM (crtinfo.asm, str2vbuf.asm, strlen.asm, $wdata.asm, a$putw.asm) Call with: ESI pointing to the string EBX pointing to window corners AH = color attribute Returns: nothing Uses: nothing Supports: all ASM32 text modes; includes CGA snow control Example: extrn wframe:proc, wprint:proc include dataseg.inc ; data wdata dw 10,10,20,30 ; window corner data: upper left at row 10, ; column 10; lower right at row 20, column 30 string db "The quick brown fox jumped over the lazy dog's back",0 @curseg ends include codeseg.inc ; code . . . lea esi,string ; ESI points to the string lea ebx,wdata ; EBX points to corner data mov ah,12 ; bright red!! call wprint dec wdata ; stretch the window borders a bit dec wdata+2 ; so I can draw a frame around the silly text inc wdata+4 inc wdata+6 mov al,-1 ; double-line border mov ah,14 ; bright yellow call wframe 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� WRECOLOR: change selected color attributes in a window of the screen Source: wrecolor.asm ($wdata.asm, crtinfo.asm, $recolor.asm) Call with: EBX pointing to window corner data AL = color attribute to be replaced AH = new color attribute Returns: nothing Uses: nothing; all registers and flags are saved Supports: all ASM32 text modes; includes CGA snow control Example: include dataseg.inc ; data wdata dw 10 ; row0 dw 10 ; column0 dw 20 ; row1 dw 40 ; column1 @curseg ends include codeseg.inc ; code . . . lea ebx,wdata ; EBX points to window coordinates mov ah,newcolor ; AH = new color attribute mov al,oldcolor ; AL = color to be replaced call wrecolor ; replace oldcolor with newcolor ; within the window 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� WRESTORE: restore a portion of a text-mode screen from a buffer WSAVE: save a portion of a text-mode screen to a buffer (handy when using pop-up windows on the screen) Source: wsave.asm ($wdata.asm, crtinfo.asm, $wcopy.asm) Call with: EDI pointing to memory buffer EBX pointing to corner data The memory buffer must be sized to hold the entire window. See wsize. Returns: nothing Uses: nothing Supports: all ASM32 text modes; includes CGA snow control Example: include dataseg.inc ; data wdata dw 10 ; row0 dw 10 ; column0 dw 20 ; row1 dw 40 ; column1 buffer dw 2000h ; oversize @curseg ends include codeseg.inc ; code . . . ; save a part of the screen lea ebx,wdata ; EBX points to window coordinates lea edi,buffer ; point to buffer call wsave . . . ; sometime later ... ; restore the window saved earlier lea ebx,wdata ; EBX points to window coordinates lea edi,buffer ; point to buffer call wrestore