i/o board

HELP US HELP YOU

I want to praise Antic for having the brains to publish "Brain Research with the Atari." I was sure an article like this would have been considered of too limited interest to have been published. Personally, I'd like to hear more about constructive uses of the Atari. I'm tired of games. Why can't your magazine offer a wider spectrum of articles?
Chuck Smithson
Reno, NV
We want to be of use to our readers. The only way we can be of use is to know what readers want to see and the best way to communicate this is to write us
-ANTIC ED

CURING COLOR DISTORTION

I have a problem with my BMC color monitor: distortion is caused when I use the RF modulator and my Atari. Contrasting colors aren't sharp, but often bleed several pixels to the right or cast shadows. Even in BASIC, using the default colors, characters cast a shadow about one-third the character width, to the right.
I sent the computer to Atari and they said it was a problem with the 1200XL. When they were done, it was "fixed," several changes had been made in the computer, and the problem still exists. Calling back, I was told they did not know how to fix it. Can you help me?
Michael Rutheford
Houston, TX
We're Passing this along to you, our readers. If anyone has a solution, or ideas, let us know. -ANTIC ED

I/O ODDITY

When I work in immediate mode and I write

POKE 710,0:POKE 709,9:
LOAD "D:FILE.EXT"

I hear the loading program sound before the screen turns black. Why?
Ivan Antezana
Lima, Peru
Every 1/30th of a second, during the stage two vertical blank interval, certain registers in the operating system (OS) in ROM look into related registers in RAM and steal the values for their own use. The RAM registers are called shadow registers to the ROM registers. In the case of your program line, 709 and 710 are shadow registers for locations 53271 and 53272. The program line is being processed so fast by BASIC that it begins execution of the file I/O before the OS registers can get the new color values from the shadow registers. During I/O, the Critical I/O Region Flag at location 66 is set, which suspends the vertical blank transfer process, and the ROM registers have to wait to get their new colors. If you add just the slightest delay after the two POKEs in your line, (such as PRINT CLOG(8)) the registers will have the time to transfer colors and your screen will change before the drive runs. -ANTIC ED

RIBBON RESURRECTION

A tip for Atari 1027 printer owners: If you've had the same trouble I've had finding replacement ink rollers, buy an inexpensive stamp pad inker (roller type) and ink the roller with it. This produces much clearer, better defined letters than even a new roller!
Gene Schoepp
Barnegat, NJ

ACTION! HELP

O.S.S.'S Mike Fitch was kind enough to pass along some information regarding Dave Plotkin's "Lights, Camera, ACTION!" article in the July 1984 issue. The SAVETEMPTS and GETTEMPS routines described there are adequate only if the interrupt routine does not perform mathematical operations other than addition and subtraction. The following versions of those routines will work properly in more general cases. Change the arrays in SAVETEMPS and GETTEMPS to the following:

SAVETEMPS="[$A2 $07 $B5 $CO $48 $B5 $A8 $48 $B5 $AO $48 $B5 $80 $48 $CA $10 $F2 $A5 $D3 $48]",
GETTEMPS="[$68 $85 $D3 $A2 $00 $68 $95 $80 $68 $95 $AO $68 $95 $A8 $68 $95 $CO $E8 $EO $08 $DO $FO]"

STAR RAIDERS

In response to Carol Waskowski's inquiry in the July I/O Board about others attaining Star Commander Class 1 in Star Raiders, I can proudly announce that I have obtained that level on many occasions. (Although Star Raiders remains one of the most popular Atari games, only a handful of readers indicated that they have achieved commander 1 status-ANTIC ED)
   The difference between Star Commander 5 and 1 is one's efficient use of energy. Here are some tips to help you save energy and improve your score.
   When entering an enemy-occupied quadrant, don't engage your engines. Let enemy ships come to you. Never chase enemies with damaged engines, for the energy you waste is more than the value of the enemy ship.
   Attempt to destroy distant ships as soon as they are in sighting range, about 120 centrons. This requires pinpoint firing, but can be done with practice. This helps avoid the close combat that is so deadly at higher levels-hits on your shields cost 100 units each,
   Always know where the nearest starbase is, and follow the advice in the third paragraph of survival tactics in the game booklet.
   Turn off shields when you're not in combat. This saves energy. There is a chance of asteroid collision, but it is slim.
   There are other tips, but this should help. The main idea is to conserve energy.
David Horne
Foster City, CA

WIPE OUT YOUR PROGRAM WITH ONE SIMPLE POKE

For those jaded Atari owners who are looking for just one more thing to do with their machines, we offer the following: POKE 202,1. Place this poke in your favorite program and your program will be wiped from memory when it ends. Your program will also be wiped if you hit [BREAK] or [SYSTEM RESET]. In fact, anything which generates the READY prompt will result in erasure of the program. Interesting possibilities for protection schemes, no? Location 202 is the Load in Progress flag. When it has been set (by poking with a 1) the computer begins part of the load procedure immediately following the generation of the READY prompt. Among other things, the load procedure clears all program lines and variables from memory.
-ANTIC ED

INVESTIGATING WITH ATARI

I am in the business of motor vehicle accident investigation and reconstruction. Are there any Atari programs available for purchase that deal with accident investigation, vehicle weights and measurements?
Eldon Shannon
Huntsville, AL
We don't know of any, but if anyone does, we'll pass the information along.
-ANTIC ED

INTERFACING COMPUTERS

I own both an Atari and a TRS Model 100. I use the TRS extensively at work and on the road, and the Atari at home. I would like to transfer text and download files from the TRS to the Atari.
Denny Bowen
Crystal Lake, IL
Please see the "Electronic Notebook" article in the July, 1984 issue of Antic. It describes techniques for using the RS-232 connector (you'll need an 850 interface) and terminal software for both computers. This allows the machines to transfer data in ASCII. -ANTIC ED

THE EDGE OF LETTER PERFECT

When using Letter Perfect on my color TV I can't see the first letters on the left. This may be due to the kind of TV I'm using here in the Amazon jungle. Is there anything I can do about this?
Carlos Malaga
Inquitos, Peru
The new Letter Perfect (version 6.0) has a Fix Window Width function that allows you to set the width of your display. Press [CTRL] [3] If you don't have this updated version, contact LJK Enterprises.
-ANTIC ED