Exit, Field, For-Next-Step, Error expression | Intel 9800758-02

BASIC-SO

Commands and Statements

ERROR expression

10 INPUT A,B,C

12IF B=O THEN ERROR 11

14PRINT AlB

20END

RUN

? 40,0,17

DIVISION BY ZERO IN 12 Ok

EXIT

The EXIT command terminates operation of the BASIC-80 interpreter and returns control to ISIS-II. EXIT closes all open files, but does not automatically save pro- grams. If you EXIT without saving the current program, it will be lost.

EXIT

FIELD

The FIELD statement is used to allocate space within one of six 128-byte BASIC-80 random file buffers. When a random 110 transaction occurs, data move to or from the specified random file buffer to or from disk sectors. The FIELD statement associates the data with its position in the 110 buffer so that future references to the specified variable will access the proper string characters or numbers within the record stored in the random file buffer. The example below shows how FIELD is used. For further information, refer to the BASIC-80 Disk Input/Output section.

FIELD # file number,

number of characters AS string variable

[,number of characters AS string variable] ...

The program below opens random file :F1 :FILE.1 and asks for five 30-character strings to insert into :Fl :FILE.1.

10OPEN "R" ,#1, ":F1 :FILE.1"

20FIELD #1,30 AS A$

30FOR 1=1 to 5

40INPUT Z$

50LSET A$ = Z$

60PUT#1,1

70NEXT I

80CLOSE#1

90END

FOR-NEXT-STEP

The FOR-NEXT statement allows the execution of a given group of lines a given number of times. As shown in the example below, on each iteration of the routine, value A is incremented by the value given in the STEP instruction. If no value for STEP is specified, the increment is 1. The instruction lines following the line con- taining the FOR instruction are executed until the NEXT instruction is encountered. Program control returns to the FOR instruction line, STEP is added to the value of A, and the routine is reentered. When variable A exceeds the TO expression, control passes to the instruction line following the NEXT instruction line.

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Image 47

Intel 9800758-02 Exit, For-Next-Step, Error expression, Field # file number Number of characters AS string variable

Contents

BASIC-SO Reference Manual A108/0979/7500 FL Preface Page Contents Illustrations Invoking BASIC-80 Chapter Introduction to BASIC-80 Filename ExamplesIntroduction to BASIC-80 Basic filename MEMTOPaddress Deleting a File Listing the Directory of a DiskRenaming a File Changing File Attributes Save LP ,A You can now run, list, or edit the program Statements Commands BASIC-80 Statements BASIC-80 Commands Contd BASIC-80 Functions BASIC-80 Statements Contd BASIC-80 Functions Contd Functions Representing Data Hexadecimal Integer Constants ConstantsInteger Constants Decimal Integer Constants Double-Precision Floating-Point Constants Octal Integer ConstantsSingle-Precision Floating-Point Constants $ = Enter next data string String ConstantsString Variables This is a string constant YI,1 L4! = Csng l4 String Arrays BASIC-SO Operators in Order of Precedence Contd Arithmetic Operators String Expressions Logical OperatorsString Operator Numeric Expressions Entering and Editing Programs 30 A--=8xx*522537 Control-R a = 8*37 30 A=8*5230 A=8 30 A=8*52 30 A=8*37 If AB then SubcommandCommand 3D press 3, then D results Integer D If AB then 120 Else Null SET At this point, the other editing subcommands may be used Syntax of the X subcommand is Print Undefined SET. Enter a L Print Undefined SET The E subcommand is enteredInteger C character character Move the cursor to PRINT. Enter 2C RE L Overflow, Underflow, and Divide-by-Zero BASIC-80 Error MessagesSyntax Error Messages Error Trapping Trace Facility If line 40 is replaced with Error SimulationError Handling Restarting Program Execution Open 1,#1,F1DATES Opening a Sequential File If executed four times, it would read all eight values Refer to for further details of Print UsingWriting to a Sequential File Reading from a Sequential File Value of R$ would be Closing a Sequential File Field #3, 20 AS N$ BuffersDefining a Random 1/0 Field-FIELD Field #3, 20 AS N$, 9 AS SS$ Disk File Input/Output To read the next record Opening and Closing a Random Disk FileReading from a Random 1/0 File Any of the parameters can be variables Double-precision value Writing to a Random 1/0 FileInteger Single-precision value MKI$ Clear expression,address Attrib Fdrive numberfilename, W1Attrib Fdrive numberfilename, WO Auto first lineJ, increment Close Commands and Statements Rules for function name are the same as for variable name DEF FNX Defsng Defdbl Defstr Defint Delete DIM END ErrorDIR Edit FOR-NEXT-STEP Error expressionExit Field GET I file number ,record number GETGosub For variable=expression to expression Step expression Goto IF-THEN-ELSEInput List KillLET Line Input Load LSET, Rset NEW Merge 9 16 Next Open On ... GosubOn ... Goto Poke Option BaseOUT String Fields Print UsingPrint If X$=SEVEN and Y$=EIGHT, the results of line 40 would be Numeric fields PUT Prun Read Randomize REM Return Resume 60 END SaveRUN line numberlstring expression ,F Line number RUN filename ? 5,8,2 TRON, Troff Width Wait ATN ABS Functions CHR$Cint AO/o = CsngCVI CVS 10 A# = 1.00/3.00 EOF Dskf Ok· FIX Inputs HexsINP LEFT$ INTInstr LOG LENLOC LOF OCT$ MID$MKI$ MKS$ MKD$ RIGHT$ string,integer RightsPeek expression POS integer 10 a =1 SGNSIN Spaces SQRexpression SPCSPC integer If A$ = 2 then Print Correct Else Goto TAN expression STR$ expressionTAB expression 60 AO/o = Here is an example of how the USRn statement is used Table A-I. BASIC-80 Error Codes Appendix a BASIC-SO Error Codes Table A-I. BASIC-SO Error Codes Contd Appendix B BASIC-SO Reserved Words Page To resume program execution after it is stopped by To halt program execution and return to commandLevel To tab across the linePage Appendix D Ascii Codes Table D-l. Ascii Code List BEL Table D-2. Ascii Code Definition Appendixe Calling Subroutines Figure B-1. Internal Representation of Numbers and Strings RESULT=USR%1VARPTRA, VARPTRB, VARPTRC» PRINTA+B+C= Result Some Real Examples Figure E-2 /8085 Assembly Language Program Figure E-3. PL/M-80 Program Appendix F RMX/SO BASIC-SO ISIS-II BASIC-SO Initializing the Predefined RMX/SO BASIC-SO Configuration OOOOH-OFFFH Table F-l. Sample Configuration Jumper Wiring BASIC-80 Executable Files Generating Boot-Loaded and PROM-Based VersionsBASIC-80 Source Files BASIC-80 Object Files Generating a Boot-Loaded RMX/80 BASIC-80 This option enables your user-written I/O drivers if you That are not boot loadedThis option is used to allocate memory. It is 1 if the boot Setting baud rates, refer to the RMX/SO Users Guide ISBC 80/20-4 Generating a PROM-Based RMX/80 BASIC-80 Prom F1 RMX820.L1BSTART, & FOBASCM.OBJ,& FORMXBAS.LlB F1 DFSDIR. L1BDIRECTORY ,RENAM E,& F1 MTI810.L1B ISBC SO/10 System Clock Configuring DFS on an iSBC 80/10Adding BASIC-SO to an Existing RMX/SO Configuration Configuration Requirements Public Variables Open 0,#1, L1LlST Adding User-Written I/O Drivers to RMX/SO BASIC-SO Figure F-S. Sample User-Written 1/0 Driver Routine Burning a BASIC-80 Program Into Prom Altering BASIC-80 Workspace Baprom F1HEATER.BAS Page Index Ase BASIC-80 RIGHT$,7-1O Request for Readerscomments 111111