Tech Tips

WINDOW OPENER

This tip comes from Antic Technical and Online Editor Charles Jackson. Window Opener is a short, simple demonstration of a useful method for controlling text windows in BASIC. When RUN, the program draws an attractive moire pattern in Graphics 8. Afterwards, press [D] to bring up the text window without clearing your screen. Press [K] to remove the text window and restore the underlying graphic.

The trick is in the Graphics command. Add a 32 to the Graphics mode number to add a text window to your screen (see line 200). Add a 48 to the mode number to remove the window and restore your screen (see line 110).


LISTING   WINDOW.BAS Download

PARTIAL SCREEN CLEAR

Robby Chavers of Tampa, Florida, contributed this little program that lets you choose any point on a Graphics 0 screen and clear all the screen area below it, leaving the remainder intact. This program fools BASIC into thinking that the screen position was moved down by changing the values in memory locations 88 and 89. To change the number of screen lines you don't want to clear, change the value of LINE in line 120 to any number up to 23.

	100 POKE 82,0:? CHR$(125);
	110 FOR P=0 TO 340:? P;:NEXT P
	120 LINE=18:GOSUB 1000
	130 END
	1000 C=PEEK(88):D=PEEK(89)
	1005 ADD=C+D*256+LINE*40
	1010 A=INT(ADD/256):B=ADD-A*256
	1020 POKE 88,B:POKE 89,A:? CHR$(125)
	1030 POKE 88,C:POKE 89,D
	1040 POSITION 0,LINE:RETURN

LISTING: SCRNCLR.BAS Download

FAST CURSOR XL/XE

Fast Cursor comes from Trevor Maingot of Ventura, California. Cursor speed is controlled in memory location 730, which normally has a value of 6. This program stores a 2 in location 730, thus greatly increasing cursor speed. NOTE: Fast Cursor doesn't work on the Atari 800 or 400 models.

When you see the onscreen message saying that the Fast Cursor routine is installed, press [RESET] to activate it. Now the only way to get rid of Fast Cursor is to turn the computer off.

	10 FOR 1=260 TO 277:READ A:POKE I,A:NEXT I
	12 ? "FAST CURSOR INSTALLED, PRESS RESET, THEN TYPE 'NEW' AND
	   GO ABOUT YOUR BUSINESS"
	15 X= USR(260)
	16 END
	20 DATA 169,2,141,218,2,169,4,133,2,169,1,133,3,169,3,133,9,96

LISTING   FASTCRSR.BAS Download

Antic pays $25 for every original and exclusive Tech Tip submission that we publish. Send your 8-bit or ST disk and printout to: Antic Tech Tips, 544 Second Street, San Francisco, CA 94107. Tech Tips welcomes very short programs that demonstrate the Atari's powers, simple hardware modifications, or useful macros for popular software.