## I/O BOARD

**REACTION**

Your new program listing approach contains two elements that have a tendency to increase the typing error rate, at least for me. When looking for erroneous entries, I check to see that the line wraps at the correct point, and that the last character of a logical line aligns with preceding lines. Your new "typeset listings" violate the conditions that allow me to proofread listings using my technique.

I thoroughly enjoy ANTIC, and am very happy to see you are going monthly. Please give some thought to my reaction to your new format.

Curtis P. Hedman

Saint Paul, MN

*Your solution requires true monospacing for all characters, including
punctuation and the "custom" graphics set. There is no such font
yet available. *--ANTIC ED

**CONTRIBUTION**

I have come up with a neat little program that displays GTIA Mode 11. The listing looks simple, but it draws a complex picture. Here is the program:

Tim Miltz

Indiana, PA

`10 X1=0:X2=80:Y1=0:Y2 =192:GRAPHICS 11
20 X1=X1+1 :X2=X2-1 :Y1=Y1+ 1:Y2=Y2-1
30 IF Y2=0 OR Y1=192 THEN X 1=20:X2=60:Y1=48:Y2=144
35 IF X1>=80 THEN X1=79
40 PLOT X1,Y1:DRAWTO 80-X1,192-Y1
60 PLOT X1,Y2:DRAWTO 80-X1,192-Y2
65 IF X2=0 THEN X2=1
70 PLOT X2,Y1:DRAWTO 80-X2,192-Y1
80 COLOR C:C=C+1:IF C=15 T HEN C=1
90 GOTO 20`

**RECREATION**

I recently received an ATARI 800 for Christmas, and every day after school I use it. Here is a program I wrote myself. I got the idea from your issue on Sound and Music. I call it the TMT SPECIAL. Hope you like it.

T. Michael Tebo

West Chester, PA

`5 REM **TMT SPECIAL**
10 GRAPHICS 3+16
20 FOR A=0 TO 2
30 COLOR A
40 FOR B=1 TO 15
50 FOR C=2 TO 14 STEP 2
60 SETCOLOR 4,B,C
70 SOUND 0,B*C,10,8
80 SOUND 1,210-B*C,10,8
90 PLOT B,C:DRAWTO C,B
100 PLOT 11+B,4+C:DRAWTO 1 1+C,4+B
110 PLOT 21+B,C:DRAWTO 21+ C,B
120 FOR W=1 TO 25:NEXT W
130 NEXT C
140 NEXT B
150 NEXT A`

**ROOT FUNCTION**

I am a high school freshman. My interest in math, and the lack of any root function in ATARI BASIC other than square root, led me to create a method of returning any root of any number. My method is based on the "Logarithm of the Root Law" which states that the Log of the Bth root of A equals (Log A) / B or (1/ B)Log A.

Darron Bacall

Staten Island, NY

`10 REM CALCULATION OF THE X ROOT OF N
20 ? "NCLOG OF THE X ROOT OF N=(1/X)*CLOG(N)":?
30 ? "N="j:INPUT N:?
40 ? "X=";:INPUT X:?
50 ? "(1/X)*CLOG(N)=";
60 Y=(1/X)*CLOG(N)
70 ? Y:?
80 W=10 ^ Y
90 ? "THE X ROOT OF N =";
100 ? W`

**MODULATION**

I am learning Assembly Language, and am trying to design a new game. I can't figure out how to change graphics modes while under the power of the Assembler Editor cartridge.

Chris Voigt

Shoreham, NY

*We posed this question to Jerry White, who responded with the following
self-documented Assembler Editor listing. Jerry suggests that, when printing
characters to the screen in Assembly Language, that you stick to using documented
ROM jump uectors such as the Central 1/0 routine Vector (CIOV at SE456)
as described in De Re Atari, rather than using the put character subroutine
at $F6A4. *--ANTIC ED

0100 .OPT NOEJECT 0110 ; MODE1.SRC BY JERRY WHITE 0120 ; 0130 ; THIS ASSEMBLER CODE SIMULATES 0140 ; THE FOLLOWING BASIC PROGRAM: 0150 ; 0160 ; CLOSE #6 0170 ; GRAPHICS 1 0180 ; PRINT #6;"GRAPHICS MODE ONE" 0190 ; PRINT "TEXT WINDOW" 0200 ; 0210 ; ASSEMBLE THEN 0220 ; EXECUTE FROM BUG (G620) 0230 ; 0240 ; 0250 *= $600 ; RELOCATABLE 0260 ; 0270 DEV .BYTE "S:" ; SCREEN 0280 MSG1 .BYTE "GRAPHICS MODE ONE",$9B 0290 MSG2 .BYTE "TEXT WINDOW",$9B 0300 ; 0310 LDX #$60 ; IOCB #6 0320 LDA #$C ; CLOSE 0330 STA $342,X 0340 JSR $E456 ; LET CIOV DO IT 0350 ; 0360 LDX #$60 ; IOCB #6 0370 ; 0380 LDA #$3 ; OPEN 0390 STA $342,X 0400 LDA #DEV&$00FF ; ADDRESS 0410 STA $344,X 0420 LDA #DEV/256 ; OF DATA 0430 STA $345,X 0440 LDA #$1C ; READ/WRITE 0450 STA $34A,X 0460 LDA #$1 ; GR. 1 0470 STA $34B,X 0480 JSR $E456 ; LET CIOV DO IT 0490 ; 0500 LDX #$60 ; IOCB #6 0510 LDA #$9 ; PUT RECORD 0520 STA $342,X 0530 LDA #MSG1&$00FF ; ADDRESS 0540 STA $344,X 0550 LDA #MSG1/256 ; OF DATA 0560 STA $345,X 0570 LDA #$12 ; LENGTH OF 0580 STA $348,X 0590 LDA #$0 ; MSG1 0600 STA $349,X 0610 JSR $E456 ; LET CIOV DO IT 0620 ; 0630 LDX #$0 ; IOCB #0 (TEXT) 0640 LDA #$9 ; PUT RECORD 0650 STA $342,X 0660 LDA #MSG2&$00FF ; ADDRESS 0670 STA $344,X 0680 LDA #MSG2/256 ; OF DATA 0690 STA $345,X 0700 LDA #$D ; LENGTH 0710 STA $348,X 0720 LDA #$0 ; MSG2 0730 STA $349,X 0740 JSR $E456 ; LET CIOV DO IT 0750 BRK ; END DEMO

**OBJECTION**

I object to your encouraging the use of such products as Micropainter, Paint, and Versawriter in your cover art contest. Those of us who do not own any of these do not have a fair chance to win.

Concerned Programmer

*One of the first entries to the contest was a very impressive full-color
drawing done in Graphics Mode 7 in BASIC A+. The ATARI's inherent graphics
capabilities are quite powerful and may be readily harnessed without special
software. *--ANTIC ED

**TRANSLATION**

Are Microsoft BASIC and Applesoft BASIC compatible? Could I use Apple programs in my ATARI? Why or why not?

David Moore

Ballston Lake, NY

*You can't use Apple programs on your ATARI. Each machine has a distinctly
different Operating System, and the ATARI has additional chips not present
on the Apple. There are many similarities among the various forms of BASIC,
and if you familiarize yourself with them, it is possible to "translate"
BASIC programs from one machine into BASIC programs for another. The ATARI
Microsoft BASIC manual includes a section on converting programs.* --ANTIC
ED