Amstrad DDI-1 manual Introduction to Logo, What is Logo

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CHAPTER 4

Introduction to LOGO

This Section is intended to introduce the subject of LOGO, with examples, and provide a guide to the commands available. It is not intended to be an exhaustive tutorial or reference guide. That will be provided by A GUIDE to LOGO (SOFT 160)

Subjects covered are:

•Concept of LOGO

•Loading and Running Dr LOGO

•Turtle Graphics

•Writing your own procedures

•Editing your own procedures

4.1 What is LOGO

Logo can help you grow as a programmer, whether or not you have ever programmed before.

Logo is a powerful programming language that is rapidly gaining popularity because it is so easy to learn and use.

You use procedures as building blocks to create Logo programs. Dr. Logo itself is a collection of procedures, called primitives, that you use to build your own programs.

During the 1970's, a team of computer scientists and educators under the direction of Seymour Papert, developed Logo with turtle graphics to allow very young children to program and use a computer.

They developed the turtle so that young learners could have, as Papert says, "an object to think with", a tool to help them learn in new ways.

In the form of an arrow head, the turtle can be directed across the screen by the use of simple commands.

Chapter 4.

AMSTRAD Disc Drive & Interface DDI-1 Manual

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Contents Page Amstrad Disc Drive & Interface DDI-1 Amstrad Contents Contents Page Connecting the Mains Lead Foundations 1 Setting UpConnecting the DDI-1 to the Computer Computer Interface Unit Main Disc Drive Drive a Computer Write Protection Foundations 2 About DiscsOpen Closed When Your Disc Is Eject Button Indicator LampROLCAVE. not found Drive a disc missing Retry, Ignore or Cancel?Foundations Loading Software/Games Run rolcaveType mismatch Bad commandSyntax error Drive a read fail Retry, Ignore or Cancel?Foundations Introducing Amsdos and CP/M Tape.in Drive B disc missing Retry, Ignore or CancelLoad filename DiscCpm First Steps Using The CP/M DiscStoring Data Onto Disc CLS? Saving a Program in Memory onto Disc Back to AmsdosBeware EXAMPLE.BAS CatalogLoading From Disc Copying Programs From Disc to Cassette Copying Programs From Disc to DiscCopying Programs From Cassette to Disc Copying Using Disccopy Copying Using the CP/M System DiscDo you want to copy another disc Y/N Copying Using CopydiscCopying started Reading track 0 to Writing track 0 toChkdisc Checking DiscsAborting DiscchkInstallation Amstrad Disc Drive & Interface DDI-1 Manual Making Working Discs Backup Master DiscDISCCOPY.COM Working SYSTEM/UTILITY discBasic only disc Turnkey Amstrad Basic discsCreating a Turnkey CP/M System disc Turnkey Basic using disc suppliedTurnkey CP/M Discs Turnkey Basic onto your Working discAmbiguous filename Confirm individual files Y/N ? Configuring a CP/M ProgramConfiguring the Output from the package Payroll Configuring the Input to the packageStarting a Turnkey CP/M Package Autostarting a Turnkey CP/M Package Introduction Amsdos PrimerConstruction of Filenames Disc DirectoryAmsdos filenames and filetypes Save PROG.BAS a Save Bprog .BAS Amsdos headersFilenames on two drives BERT.BAS FRED1.BAS FRED2.BAS FRED3.BAK FRED3.BAS FINISH.BAS Examples of Using Amsdos Commands in a programWild cards Saving variables and performing a Screen DumpCloseout NeatWend Closein Reference guide to Amsdos commandsPre-empting a Garbage Collection While not EOFCAT Summary of Basic commandsSummary of Amsdos external commands Save OPENOUT, Print #9, Write #9, List #9, CloseoutDISC.IN CPMDIR DiscTAPE.IN ERAREN TapeAscii files File Copying proceduresCopying Files Amsdos files with headersFile has a header Amstrad Reference guide to Amsdos Error Messages Drive Drive write fail Drive Drive disc missingDrive Drive disc is write protected Drive Drive read failCP/M system tracks CP/M PrimerOperating with CP/M Logging in a disc Configuration SectorConsole control codes ERA command Direct Console CommandsSwitching default drives DIR commandPeripheral Management Transient commandsREN command Type commandCassette files File and disc copyingSingle file copying Whole disc copiers and checkersStat System ManagementIs this correct Y/N SetupDo you want to update your system disc Y/N Stat SECRET.BAS $DIRFormat D Format I Format Disc GenerationAmsdos FormatSysgen BootgenAdvanced programming MovcpmAmstrad Disc Drive & Interface DDI-1 Manual Introduction to Logo What is LogoGetting Started Dr. LogoTo squareanysize side repeat 4 fd side rt 90 end Procedures with parametersRepeat 4 fd 60 rt To square Repeat 4 fd 60 rt 90 endTo triangle Repeat 3 fd edge rt 120 end Using Variables to remember valuesEditing programs and procedures Cs squareanysize 100 rt 45 squareanysizeSummary of Dr. Logo primitives Operating hintsCount Word and List ProcessingAscii CharList EmptypFirst FputArithmetic Operations Logical Operations ?= Logo Logo NotVariables ProceduresShow EditingText Screen SetsplitDot CleanGraphic Screen TypeWindow PalSetpal Wrap Turtle GraphicsSetpc SethNodes Workspace ManagementSetpos ErnPlist RecycleGlist GpropKEYBOARD, Joystick buttonp Disc Files DirLoad Save?key Paddle?paddle 0 ?make key rcRelease SoundEnv EntStop LabelRepeat RunThrow ErrorCatch PauseSystem Properties Headers Technical information for the user FirmwareStore requirements Changing DiscsAmsdos messages Error MessagesBios messages Failed to load boot sector Common to ALL Formats Disc OrganisationReturn Parameters Jump Block Interception by AmsdosJump Block Re-Interception by the User 137 #BC9B Intercepted Firmware Calls132 #BC8C 133 #BC8F 134 #BC92 135 #BC95 #BC98 Page Appendix Glossary of Terms CP/M Dr.Logo Primitives TPA Amstrad Disc Drive & Interface DDI-1 Manual Appendix Term Limitations of Remedies Amstrad Disc Drive & Interface DDI-1 Manual Appendix Index ERA Setpos