I've found a couple of minor bugs in "GTIA Sketchpad" (ANTIC, December 1983). If you move the cursor to the top of the screen in the "Doodle" mode while you're pressing the joystick's fire button (to create a wide line), you get an error message. To remedy this, change line 800 as follows:
800 IF YP < N1THEN YP=148
If you move the cursor to the far left of the screen while pressing the fire button, it doesn't wrap around. To fix this, make the following changes to line 790:
790 IF XP < N1 THEN XP = 78
These changes should make debugging easier.
TAKE IT FROM THE TOP
There is a minor flaw in "Air Raid 2000" (ANTIC, November 1983) by Erik Wolpaw. The title of the game flashes on the screen constantly. This is distracting and hard on the eyes. To remedy this, simply change the inverse-video title of the game in lines 1120 and 1370 to normal video.
All in all, however, I'd like to congratulate Erik on a job well done - keep it up!
In the "ANTIC Pix Controllers" survey (December 1983), we gave an incorrect address for Questar Controls, Inc., the manufacturer of the Questar Control Console and the Blaster. Their correct address is: 799 Main St., Half Moon Bay, CA 94019.
A LOT OF ROT
The listing for my new "DOS Sectors to Forth" article (ANTIC, page 32, October 1983) contains a misprint at the end of the fourth line. The word "tROT" should be "< ROT." This command causes a left rotation of the stack - in other words, it moves the top of the stack to the third position from the top. This word can be implemented as "LROT" in some versions, and is defined as:
:< ROT ( N1 N2 N3 - N3 N1 N2 ) ROT ROT ;
Bill Van Hassel
New Hope, PA
EPSON RX-80 PRICE
We provided incorrect price information on the Epson RX-80 printer in our recent "Printer Survey" (ANTIC, January 1983). The correct prices are $399 for the standard model and $599 for the RX-80 with the friction feature. The $299 price was an authorized introductory sale price.
In the game "Tag" (ANTIC, November 1983, p. 84), the screen is supposed to clear after every minute of play. However, due to an oversight, it does not. To effect this feature, change line 95 to:
95 POKE 540,60:S=S+1:IF S =60 THEN M=M+1:?#6;CHR$(125):S=0