GWBASIC User's Manual - divonasperi.it

1 GWBASIC User's ManualUser's GuideChapters1. Welcome2. Getting Started3. Reviewing and Practicing4. The Screen Editor5. Creating and Using Files6. Constants, Variables, Expressions and OperatorsAppendiciesA. Error Codes and MessagesB. Mathematical FunctionsC. ASCII Character CodesD. Assembly LanguageE. Converting ProgramsF. CommunicationsG. Hexadecimal EquivalentsH. Key Scan CodesI. Characters RecognizedGlossaryUser's ReferenceABS FunctionASC FunctionATN FunctionAUTO CommandBEEP StatementBLOAD CommandBSAVE CommandCALL StatementCDBL FunctionCHAIN StatementCHDIR CommandCHR$ FunctionCINT FunctionGW-BASIC User's GuideMicrosoft CorporationInformation in this document is subject to change without notice and does not represent a commitment on the part of Microsoft Corporation.

2 The software described in this document is furnished under a license agreement or nondisclosure agreement. It is against the law to copy this software on magnetic tape, disk, or any other medium for any purpose other than the purchaser's personal use. Copyright Microsoft Corporation, 1986, 1987. All rights copyright COMPAQ computer Corporation, 1985 Simultaneously published in the United States and , MS-DOS , GW-BASIC and the Microsoft logo are registered trademarks of Microsoft is a registered trademark of COMPAQ computer is a registered trademark of Digital Equipment Number 410130001-330-R02-078GW-BASIC User's ReferenceMicrosoft CorporationInformation in this document is subject to change without notice and does not represent a commitment on the part of Microsoft Corporation.

3 The software described in this document is furnished under a license agreement or nondisclosure agreement. The software may be used or copied only in accordance with the terms of the agreement. It is against the law to copy this software on magnetic tape, disk, or any other medium for any purpose other than the purchaser's personal :///C|/Documents%20and%20 Settings/Lorenzo/Desktop/GW%20 (1 of 6)28/03/2004 User's ManualCIRCLE StatementCLEAR CommandCLOSE StatementCLS StatementCOLOR StatementCOM(n) StatementCOMMON StatementCONT CommandCOS FunctionCSNG FunctionCSRLIN VariableCVD FunctionCVI FunctionCVS FunctionDATA StatementDATE$ StatementDEF FN StatementDEFINT StatementDEFDBL StatementDEFSNG StatementDEFSTR StatementDEF SEG StatementDEF USR StatementDELETE CommandDIM StatementDRAW StatementEDIT CommandEND StatementENVIRON StatementENVIRON$ FunctionEOF FunctionERASE StatementERDEV($)

4 VariablesERL VariableERR VariableERROR StatementEXP FunctionEXTERR FunctionFIELD Statement Copyright Microsoft Corporation, 1986, 1987. All rights copyright COMPAQ computer Corporation, 1985 Simultaneously published in the United States and , MS-DOS , GW-BASIC , and the Microsoft logo are registered trademarks of Microsoft and IBM are registered trademarks of International Business Machines Number 410130013-330-R02-0787 IntroductionThis Manual is an alphabetical reference to GW-BASIC instructions: statements, functions, commands, and name and type of each instruction is listed at the top of the page, and is followed by:PurposeThe purpose of the instructionSyntaxThe complete notation of the instructionCommentsPertinent information about the instruction, and what happens when it is encountered by GW-BASICE xamplesAn illustration of the instruction as it might appear in a programNotesAny special information about the instructionfile.

5 ///C|/Documents%20and%20 Settings/Lorenzo/Desktop/GW%20 (2 of 6)28/03/2004 User's ManualFILES CommandFIX FunctionFOR StatementFRE FunctionGET Statement (Files)GET Statement (Graphics)GOSUB-RETURN StatementGOTO StatementHEX$ FunctionIF StatementINKEY$ VariableINP FunctionINPUT StatementINPUT# StatementINPUT$ FunctionINSTR FunctionINT FunctionIOCTL StatementIOCTL$ FunctionKEY StatementKEY(n) StatementKILL CommandLEFT$ FunctionLEN FunctionLET StatementLINE StatementLINE INPUT StatementLINE INPUT# StatementLIST CommandLLIST CommandLOAD CommandLOC FunctionLOCATE StatementLOCK StatementLOF FunctionLOG FunctionLPOS FunctionLPRINT Statementfile:///C|/Documents%20and%20 Settings/Lorenzo/Desktop/GW%20 (3 of 6)28/03/2004 User's ManualLPRINT USING StatementLSET StatementMERGE CommandMID$ FunctionMID$ StatementMKDIR CommandMKD$ FunctionMKI$ FunctionMKS$ FunctionNAME CommandNEXT StatementNEW CommandOCT$ FunctionON COM(n) StatementON KEY(n) StatementON PEN StatementON PLAY(n) StatementON STRIG(n) StatementON TIMER(n) StatementON ERROR GOTO StatementON-GOSUB StatementON-GOTO StatementOPEN StatementOPEN "COM(n) StatementOPTION BASE StatementOUT StatementPAINT StatementPALETTE StatementPALETTE USING StatementPCOPY CommandPEEK FunctionPEN Statement and FunctionPLAY StatementPLAY(n)

6 FunctionPMAP FunctionPOINT FunctionPOKE StatementPOS FunctionPRESET Statementfile:///C|/Documents%20and%20 Settings/Lorenzo/Desktop/GW%20 (4 of 6)28/03/2004 User's ManualPSET StatementPRINT StatementPRINT USING StatementPRINT# StatementPRINT# USING StatementPUT Statement (Files)PUT Statement (Graphics)RANDOMIZE StatementREAD StatementREM StatementRENUM CommandRESET CommandRESTORE StatementRESUME StatementRETURN StatementRIGHT$ FunctionRMDIR CommandRND FunctionRSET StatementRUN CommandSAVE CommandSCREEN FunctionSCREEN StatementSGN FunctionSHELL StatementSIN FunctionSOUND StatementSPACE$ FunctionSPC FunctionSQR FunctionSTICK FunctionSTOP StatementSTR$ FunctionSTRIG StatementSTRIG(n)

7 StatementSTRING$ FunctionSWAP StatementSYSTEM CommandTAB Functionfile:///C|/Documents%20and%20 Settings/Lorenzo/Desktop/GW%20 (5 of 6)28/03/2004 User's ManualTAN FunctionTIME$ StatementTIMER FunctionTROFF CommandTRON CommandUNLOCK StatementUSR FunctionVAL FunctionVARPTR FunctionVARPTR$ FunctionVIEW StatementVIEW PRINT StatementWAIT StatementWHILE-WEND StatementWIDTH StatementWINDOW StatementWRITE StatementWRITE# Statementfile:///C|/Documents%20and%20 Settings/Lorenzo/Desktop/GW%20 (6 of 6)28/03/2004 User's GuideChapter 1 Welcome to GW-BASICN otational ConventionsMicrosoft GW-BASIC is a simple, easy-to-learn, easy-to-use computer programming language with English-like statements and mathematical notations.

8 With GW-BASIC you will be able to write both simple and complex programs to run on your computer . You will also be able to modify existing software that is written in guide is designed to help you use the GW-BASIC Interpreter with the MS-DOS operating system. Section lists resources that will teach you how to System RequirementsThis version of GW-BASIC requires MS-DOS version or PreliminariesYour GW-BASIC files will be on the MS-DOS diskette located at the back of the MS-DOS User's Reference. Be sure to make a working copy of the diskette before you Manual is written for the user familiar with the MS-DOS operating system. For more information on MS-DOS, refer to the Microsoft MS-DOS User's Guide and User's Notational ConventionsThroughout this Manual , the following conventions are used to distinguish elements of text: bold Used for commands, options, switches, and literal portions of syntax that must appear exactly as shown.

9 Italic Used for filenames, variables, and placeholders that represent the type of text to be entered by the for sample command lines, program code and examples, and sample CAPSUsed for keys, key sequences, and surround optional command-line :///C|/Documents%20and%20 Settings/Lorenzo/Desktop/GW%20 Basic/Chapter (1 of 3)28/03/2004 User's Organization of This ManualThe GW-BASIC User's Guide is divided into six chapters, nine appendixes, and a glossary:Chapter 1, "Welcome to GW-BASIC," describes this 2, "Getting Started with GW-BASIC," is an elementary guideline on how to begin 3, "Reviewing and Practicing GW-BASIC," lets you use the principles of GW-BASIC explained in Chapter 4, "The GW-BASIC Screen Editor," discusses editing commands that can be used when inputting or modifying a GW-BASIC program.

10 It also explains the unique properties of the ten re-definable function keys and of other keys and keystroke 5, "Creating and Using Files," tells you how to create files and to use the diskette input/output (I/O) 6, "Constants, Variables, Expressions, and Operators," defines the elements of GW-BASIC and describes how you will use A, "Error Codes and Messages," is a summary of all the error codes and error messages that you might encounter while using B, "Mathematical Functions," describes how to calculate certain mathematical functions not intrinsic to C, "ASCII Character Codes," lists the ASCII character codes recognized by D, "Assembly Language (Machine Code)