Atari 130XE User Manual

Graphics Mode 3
The graphics mode 3 screen is a grid consisting of 40 columns and 24
rows (20 if you use the text window). Enter and run the following
program:
NEW
1.0 GRtliPHICS 3
20 COLOR 1.
30 PLOT 0 .. 0
RUN
In the upper left corner is an orange block. The block, or pixel, is one
unit
in the graphics screen. The COLOR command determines the
color of the pixel. The number after the COLOR command determines
which
color r eg ister to use for the color of the pixel. The COLOR com-
mand does not place a color in the register; SETCOLOR does that. The
COLOR command simply se lects which register to use to plot the
pi xe l, and the pixel becomes whatever color is in the register. To make
this clearer, change line 20 to
20 COLOR 2
Run the program. The orange pixel is now light green. Think of each
pixel as a text character. In modes 1 and 2, you used uppercase and
lowe rca se characters a nd In verse Video to se lect the colors of the
text. In modes 3 a nd above, use the COLOR command to select the
color for the pixels.
PLOT: Plotting Points on the Grid
PLOT is like the PRINT #6; command except that it prints pixels in-
stead of letters and numbers. COLOR is like the upper/lower/inverse
color selection method; it selects the registe r. The default colors are
orange, light green, dark blue, a nd black. To change the color in any
of the registers, use the
SETCOLOR command.
Th e color registers are like four buckets of paint. SETCOLOR selects
the color that goes into each of the four buckets, and COLOR selects
the bucket into which the paintbrush wi ll be dipped. PLOT determines
where the bru sh will be positioned on the screen.
DRAWTO: Connecting the Dots
Add this
line:
40 DRtliWTO 3'J .. 0
73

Atari 130XE Specifications

General

Type	Home computer
Release year	1985
CPU	MOS Technology 6502C
CPU Speed	1.79 MHz
RAM	128 KB
ROM	24 KB
Graphics	ANTIC and GTIA chips
Manufacturer	Atari
Display resolution	320x192
Sound	POKEY chip, 4 channels
Storage	External floppy disk drive, cassette tape
Ports	2 joystick ports
Operating System	Atari BASIC

Summary

Important Information

Part 1 Getting Started

Meeting the ATARI 130XE

Hooking It Up

Step-by-step instructions for connecting the ATARI 130XE to a TV or monitor.

Checking It Out

Instructions on running diagnostic self-tests for the computer.

Understanding Your Keyboard

Detailed explanation of keyboard layout, keys, and functions.

Exploring ATARI BASIC

Using Software

Part 2 Programming with ATARI BASIC

Editing with the ATARI 130XE Keyboard

Writing a Simple BASIC Program

Introduction to basic BASIC commands like NEW, LIST, PRINT, and RUN.

Creating an Interactive Loop

Using Random Numbers and Mathematical Functions

Making Decisions and Solving Problems

Using IF-THEN for decision making and FOR-NEXT for loops.

Producing Sound and Graphics

Commands for generating sound effects and creating graphics displays.

Part 3 Appendices

A. Sample Programs

D. Error Messages

List and explanation of common error codes and their meanings.

E. Troubleshooting

G. ATARI 130XE Specifications

H. Accessing the Full RAM Potential

I. Connector Pinout Specifications