ATARI CLINIC
Q. My ATARI 800, which I purchased in December 1982, locks up and displays 0's across the top of the screen with my Star Raiders cartridge. I exchanged the cartridge twice, and also had the local authorized service center check the computer. The cause of the malfunction, however, was not found. This lock-up has occurred only with the Star Raiders cartridge; all my other cartridges work fine. Do you know what might correct this problem!
Brian Honma
Honolulu, Hawaii
A. Take your compter back to the servicing dealer and have him run an extensive RAM test on your computer. If the computer does not fail, then have him swap out the ANTIC chip. That should solve your problems.
Q. I have recently typed in Chicken (ANTIC, Vol. 1, No. 1) and I had some troubles with it. After I typed it in, I saved it on my 410. I found some careless typing mistakes. I ran the program and my 400 stopped. I tried the [BREAK] key, [SYSTEM RESET] button, but nothing happened. I could not get any other key to respond.
A. Batek
Non Mills, Canada
A. Without having your computer to check out, my guess is that you have found the ever-present bug in ATARI BASIC. If your computer does not give you any more problems, I wouldn't worry about it.
Q. In the June issue of ANTIC I came across a reference to listings of schematics for the ATARI computers and peripherals. Please Send quickly. I assume that these contain schematics for the ATARI 800 computer and 810 Disk Drive.
Air-ways Dist.
Centereach,New York
A. The part number for the Technical User Notes is C016555 and it does not have any information other than for the ATARI 800 and 400. At the present time there are no plans to bring out any technical manuals of any kind for anything other than the 800,400. If you still want the User Notes, then drop us a line at Electronic Fantasy, 52 So. Linden Ave. #1, South San Francisco, CA 94080.
Q. I don't know where Mr. Switzer gets his information on cleaning disk drives, but it seems he is trying to scare the consumer away from using any of the cleaning disks on the market. He says that they might burn out the head. This is nonsense, as the current heads are made of hard ceramic and it doesn't matter whether you select a wet or dry cleaner. The wet cleaner contains alcohol and acts like a detergent to ease the process. This information comes from a Shugart factory rep.
Steve Dalton
McKeesport, PA
A. Boy, you guys won't let this die! First of all, some of the information I give is my own opinion, based on experience that I have had in this field. How much experience do you have in repairing drives? I doubt that even a factory rep has very much. I have examined drive heads that were bad and you couldn't see the scratch with the naked Eye. The heads are ceramic, but don't fool yourself into believing that they are rugged, or that they can take a beating, because they cannot! I don't know what the issue is; it is so easy and quick to wet clean the head, why take the risk? The cost of replacing the head is just not worth the convenience of using a cleaning disk.
Q. I am the owner of an Atari 1200XL computer with a 1010 recorder. I am looking for more technical data on maintaining it here.
Dalmo Pontual
Salvador, Brazil
A. I wish that I could help you more, but Atari has dropped the 1200XL from their line and has no plans to produce more. I doubt that they will support the machine with any more publications than are already out.
Tech Tip: Any time you take the bottom shield off your 400 or 800 computer, remember to put all the screws back and tighten them down all the way. The shield keeps the R.E interference down and keeps the picture on your T.V. looking clear. - Steve
Q. Hooray! We are very glad ANTIC exists. I do local television shows and would like to create titles with my ATARI computer. How do I connect my computer to something that could be recorded by a video recorder? Is it expensive? Where are the sources for such devices?
Syron Tomingas,
CA
A. This is very simple and inexpensive. Just go down to your local Radio Shack store and ask for an RCA to F adapter part #2780255 at a cost of $3.29. Plug this into the Video IN on your video recorder and plug your computer in the back of the adapter. This should work fine for what you want to do.
Q. I have an older 800, with a CTIA graphic chip in it. I am thinking of updating my computer with a GTIA. Is this expensive! Can I do it myself?
J. Ross,
OR
A. If you take your computer to a service center, it should cost you about $50 to have the GTIA installed. If you do it yourself, then first you must buy the chip (retail cost is about $20). Disassemble your computer as follows: Remove the lid that covers the memory and take out all ROM and RAM cards. Leave the tabs that retain the lid in an open position. Turn your computer over and lay it on its top. Take out the two screws at the rear of the computer, and unscrew the three screws in the front. Lift off the bottom. You will see a speaker; remove it. You will now see a metal plate that is held on with nine screws; unscrew them.
Be very careful at this point. To the left of the metal casing you will see a 22-Pin connector with pins going from the top board (mother board) to the bottom board (power supply). With your fingers lift up the mother board at the location of this 22-pin connector. As the board starts to rise, leave your left hand on the lower left corner and put your right hand on the upper right corner. Try to keep the board level as it seperates from the power supply. After the two boards seperate, stop and notice the ribbon cable that is attached to the mother board and the keyboard. Be careful with this connection. Gently pull up on the mother board, leaving the edge that is connected to the keyboard down as you bring the other up.
Look at the rear of the mother board and you will now see the C.P.U. card. Remember which way the card is facing and gently pull it out of its socket. Place the C.P.U. card so the chips are facing you (fingers down). Notice that all the chips have a dot in one corner; this tells you what direction the chips are to be in the socket. Find the chip with the number C012295 (second from the left). Insert a small screwdriver between the socket and the chip, and pry it gently. The chip should slowly come out of socket. Take the new GTIA chip, and use the little dot to guide position. Insert the chip in the socket. Look very closely to make sure that no pins are bent or outside the socket. Notice in the upper-right corner of the card a little plastic knob on a 500K pot. This is the color adjustment, don't turn it yet.
Now place the card back in the mother board and reverse all the steps you made while taking the machine apart. Be careful when putting the mother board and the power supply back together so you don't bend any of the pins on that 22-pin socket. When the plastic bottom is on, turn the machine over and install the RAM and ROM cards again.
Leave the cover off so that you can adjust the color. Look at the lower-right corner, where the door closes on the cartridges, and you will see a hole with a darker-colored, plastic piece in the hole. This is the switch that shuts the computer off when you open the door. Put a nail file gently down this hole and you will feel the switch at work.
Power up the computer and see if the color is right. If it isn't, take a small screwdriver and place it in the hole at the back of the nmetal casing. This is where the 500K pot is. Turn it until you have the right screen color. You may not be able to adjust the color perfectly but it should do. If you can't get it right, then take your computer to your nearest Service center and let them adjust it for you. If you can't find a servicer that will sell you a GTIA chip, drop us a line at Electronic Fantasy, 52 So. Linden Ave., South San Franczsco, CA 94080.
Test the new chip with this short program:
10 GR.12
20 GOTO 10
RUN
You should get a black screen rather than a blue one.
Q. Would placing my 810 drive between my 800 and my 12" television set in the same rack, cause problems with data reliability on the diskettes due to the electrical field produced from the television set?
Bruce Duckworth,
KY
A. I have only seen this problem once. We had a customer who kept bringing in his drive and telling us that there was something wrong with it. We put his drive through the most grueling tests and every time it passed. But as soon as the customer would hook up his drive at home it would fail. We finally figured out that it was his T.V. set. He moved the drive away from the set and he had no more problems. Go ahead and use your rack and position your drive any place you like. Try loading and saving some programs that you would feel safe in losing. If you don't have any problems then, you shouldn't have any in the future.