Compute! Issue 19 - December 1981. The Editors Notes The Price Wars - Ask The Readers Line Numbering Suggestion - Ask The Readers PET BASIC AID bug - Ask The Readers COMBAT variable on Atari? - Ask The Readers Apple I data - Ask The Readers Free Information Services - Ask The Readers Atari Upgrade Suggestions - Ask The Readers Running SHOOT - Computers And Society The Personal Computer As A Tool For Creative Expression - Guest Commentary: The World Computer Revisited - The Beginners Page Checksum, Terabytes, And Disaster Avoidance - Basically Useful BASIC A Quick-Fix Approach To Calculating Tables - Window Analysis Saving Fuel $$ With Your Computer - Subscript Heap Sort - Review: SYZYGY RS-232 Condition Testers - Unscramble - Maze Generator - An Introduction To Binary Numbers Part Two - Book Review: Microprocessors For Measurement And Control - Console Input/Output - MTU-130: A New 6502 Microcomputer - Animating Applesoft Graphics - Programming The Reset Key The Easy Way - A Simple Printer Interface For The Apple II - INSIGHT: Atari I/O for Extended Disk Operations - Discovering Atari's Hidden Graphics - String Art - Billiard Bounce - Blinking Characters - Make Your Atari Keyboard A Little Friendlier - Adding High Speed Vertical Positioning To P/M Graphics - A Poor Programmers Word Processor - Super Cursor V1.3 - Memory Recall Test - A Look At SuperPET - Supermon: A Primary Tool For Machine Language Programming - PET To PET Communication Over The User Port - Replacing The INPUT # Command - Typing Foreign Language Text With The Commodore Printer - Three Reviews: Superchip, Spacemaker, Sort - Machine Language Jumbo Numbers - File Recovery - Looney Line Numbers - Mine Maze - COMAL: Another Language? - CAPUTE! Corrections And Amplifications - New Products Advanced Operating Systems Publishes 10 Program Household Package - New Products Smart Terminal Program For Atari Features Autodialing - New Products Service Of Commodore Computers Begins At 38 TRW Service Centers - New Products Okidata Adds Interface Options To Microline Printers - New Products Software For The Very Young - New Products Special Learning Ed Software Presents Educational Software For The Pet - New Products PDI Establishes Division To Produce And Distribute Games - New Products Six New Superpet Books Now Available From Commodore - New Products Link Systems Introduces Datafax.