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diff --git a/bwbasic.doc b/bwbasic.doc new file mode 100644 index 0000000..2c37ba9 --- /dev/null +++ b/bwbasic.doc @@ -0,0 +1,1156 @@ + + Bywater BASIC Interpreter, version 3.20 + --------------------------------------------- + + Copyright (c) 1993, Ted A. Campbell + for bwBASIC version 2.10, 11 October 1993 + + Copyright (c) 2014-2015, Howatd Wulf, AF5NE + for bwBASIC version 3.00, 12 May 2015 + + Copyright (c) 2015-2016, Howatd Wulf, AF5NE + for bwBASIC version 3.10, 27 July 2016 + + Copyright (c) 2016-2017, Howatd Wulf, AF5NE + for bwBASIC version 3.20, 4 June 2017 + +CONTENTS: + + + 1. DESCRIPTION + 2. TERMS OF USE + 3. QUICK REFERENCE LIST OF COMMANDS, FUNCTIONS AND OPERATORS + 4. GENERAL NOTES ON USAGE + 5. PREDEFINED VARIABLES + 6. UNIMPLEMENTED COMMANDS AND FUNCTIONS + and AGENDA FOR DEVELOPMENT + 7. THE STORY OF Bywater BASIC + 8. COMMUNICATIONS + 9. EXPANDED REFERENCE FOR COMMANDS, FUNCTIONS AND OPERATORS + + The author wishes to express his thanks to Mr. David MacKenzie, + who assisted in the development Unix installation and configuration + for this version. + +1. DESCRIPTION + + + The Bywater BASIC Interpreter (bwBASIC) implements a large superset + of the ANSI Standard for Minimal BASIC (X3.60-1978) and a significant + subset of the ANSI Standard for Full BASIC (X3.113-1987), and many + classic BASIC dialects in C. + + bwBASIC can be configured to enable commands, functions, operators + and punctuation characters available in many classic dialects of BASIC; + these are controlled by various OPTION commands. bwBASIC does not attempt + bug-level compatibility with any particular BASIC dialect nor does it + currently support graphics. bwBASIC seeks to be as portable as possible. + + The interpreter is fairly slow. Whenever faced with a choice + between conceptual clarity and speed, I have consistently chosen the + former. The interpreter is the simplest design available, and + utilizes no system of intermediate code, which could speed up + considerably its operation. As it is, each line has only one + command. Multi-statement lines are internally broken into distinct + lines as they are loaded. + + +2. TERMS OF USE: + + + This version of Bywater BASIC is released under the terms of the + GNU General Public License (GPL), which is distributed with this + software in the file "COPYING". The GPL specifies the terms under + which users may copy and use the software in this distribution. + + A separate license is available for commercial distribution, + for information on which you should contact the author. + + +3. QUICK REFERENCE LIST OF COMMANDS, FUNCTIONS AND OPERATORS + + + The complete list of over 500 commands, functions and operators is + in the file "ALL.txt" in the DOCS directory. Documentation for each + BASIC dialect is in the other text files in the DOCS directory. + + A BASIC dialect is a selection of commands, functions, operators, + punctuation characters and other behaviors. The OPTION VERSION + command is used to choose a specific BASIC dialect. Additional + OPTION commands are available to fine-tune the behavior. + + In bwBASIC, any function can be executed as a command. For example, + the function "OUT(X, Y)" can be executed as the command "OUT X, Y". + You can overload functions by parameter signature (the number + and types of parameters), and user defined functions can replace + any instrinsic function, including INP, OUT, PEEK, POKE, and WAIT. + + +4. GENERAL NOTES ON USAGE: + + + 4.a. Interactive Environment + + + An interactive environment is provided if the flag INTERACTIVE + is defined as TRUE in bwBASIC.h, so that a line with a + line number can be entered at the bwBASIC prompt and it will be + added to the program in memory. + + Line numbers are not strictly required, but are useful if the + interactive enviroment is used for programming. For longer + program entry one might prefer to use an ASCII text editor, and + in this case lines can be entered without numbers. See also the + documentation below for the pseudo-command EDIT, in section 5. + + + 4.b. Naming Conventions + + + Command, function, label, and variable names are not case sensitive, + so that "Run" and "RUN" and "run" are equivalent. + + The characters allowed in variable names depends upon the specific + BASIC dialect selected with the OPTION VERSION command. Usually, + variable names can use any alphabetic characters, the period + and underscore characters and decimal digits (but not in the + first position) and they can be terminated with the various numeric + type characters (!,@,#,%,&,~) or the string type character ($). + + + 4.c. Numerical Constants + + + Numerical constants may begin with a digit 0-9 (decimal), with + the "&H" or "&h" (hexadecimal) or the "&o" or "&O" (octal). + Numerical constants may include 'E' or 'e' followed by an + exponent number to denote exponential notation. Numerical + constants may also be terminated by the various numeric type + characters (!,@,#,%,&,~). + + + 4.d. Command-Line Execution + + + A filename can be specified on the command line and will be + loaded and executed immediately, so that the command line + + bwBASIC prog.bas + + will load and execute "prog.bas". If a program is executed + from the command line, control is returned to the operating + system when the program terminates. + + + 4.e. Program Storage + + + All programs are stored as ASCII text files. + + + 4.f. TRUE and FALSE + + + TRUE is defined as -1 and FALSE is defined as 0 in the default + distribution of bwBASIC. Alhtough these definitions can be changed + by those compiling bwBASIC (see file bwBASIC.h), any other values + are not supported. + + + 4.g. Assignments + + + Assignment must be made to variables. This differs from some + implementations of BASIC where assignment can be made to a + function. Implication: "INSTR( 3, x$, y$ ) = z$" will not + work under bwBASIC. The command "MID$(X$,...) = ..." is + implemented and should be used instead. + + Some BASIC dialects allow the multiple variable assignments, + such as: + 100 LET A = B = C = 0 + In bwBASIC, only the first '=' is considered an assignment. + All other '=' are considered comparison operators. To resolve + this issue, use commas to seperate the variables, such as: + 100 LET A, B, C = 0 + If these statements are only used to initialize the variable + values, then they may not needed in bwBASIC, since all numeric + variables are initialized to zero (0) and all string variables + are initialized to the empty string (""). + + + 4.h. Operators and Precedence + + + The available operators are determined by the OPTION VERSION + setting. bwBASIC recognizes many operators, with their level of + precedence fixed. The precedence levels chosen for the various + operators in bwBASIC were selected to be compatible with many + dialects of BASIC. If your application requires a specific order + of evaluation, then use parentheses. + + The collating sequence (ASCII, EBCDIC, and so on) is determined + by the C compiler. As a consequenece, the results of string + comparisons may vary. A simple check for collating sequence is + shown in the following example: + + 100 REM Purpose: Verify collating sequence (sort order) + 110 REM Author: Howard Wulf, AF5NE + 120 REM Date: 2015-11-28 + 130 REM + 200 IF "1" < "A" THEN 300 + 210 PRINT "EBCDIC" + 220 GOTO 999 + 300 PRINT "ASCII" + 999 END + + + 4.i. Numerical Precision (NOT) + + + bwBASIC utilizes numbers with only one level of precision. + All numbers are internally represented using a C double. + + The various numeric type suffix characters (!,@,#,%,&,~), + just like the string type suffix character ($), are part + of the variable name. + + This version also supports type declarations, such as: + 100 DIM X AS INTEGER + 110 FUNCTION ABC( X AS INTEGER ) AS INTEGER + 120 LET ABC = X * 2 + 130 END FUNCTION + + For each type character there is an equivalent type declaration. + Type Equivalent + Char declaration + ==== =========== + $ STRING + # DOUBLE + ! SINGLE + @ CURRENCY + & LONG + % INTEGER + ~ BYTE + + However, combining both a type suffix character and a type + declaration in the same statement is not supported. + 100 DIM A$ AS INTEGER ' this is not supported + + The type of a variable is used to range-check the values. + This allows many programs to run correctly, but does not + handle all possible cases. The current implementation is not + complete for all possible uses of numeric type declarations. + + In the current version, the type of numeric values is used + to select the appropriate operation. As a consequence, + integer division is used when dividing two integer values. + The MOD and \ operators use the rounded integer values of + their parameters and return a rounded integer result. + + Within an expression, the result of an operation is promoted + to the greater of: + the type of the left parameter, + the type of the right parameter, and + the type required to hold the result. + + In bwBASIC, numeric constants are DOUBLE by default. If you + wish to coerce a numeric constant, then add the appropriate + numeric type character immediately after the numeric digits. + Many BASIC dialects that allow numeric constants to have a + numeric type character adopt this convention. + + + 4.j. OPTION VERSION and so on + + + OPTION commands change how a BASIC program is parsed. All OPTION commands + should be in "profile.bas" so they are effective when a BASIC program + is loaded. The first OPTION command should be OPTION VERSION to select a + specific BASIC dialect. Additional OPTION commands fine-tune the available + commands, functions, operators, punctuation characters and so on to support + programs written in many different BASIC dialects. All other OPTION commands + must follow the OPTION VERSION command. Conflicting and pathological OPTION + combinations are not supported. + + The OPTION VERSION command selects a specific BASIC dialect. + OPTION VERSION "BYWATER" ' Bywater BASIC 3 + OPTION VERSION "BYWATER-2" ' Bywater BASIC 2 + OPTION VERSION "CALL/360" ' SBC CALL/360 Mainframe BASIC + OPTION VERSION "CBASIC-II" ' CBASIC-II for CP/M + OPTION VERSION "DARTMOUTH" ' Dartmouth DTSS BASIC + OPTION VERSION "ECMA-55" ' ANSI Minimal BASIC + OPTION VERSION "ECMA-116" ' ANSI Full BASIC + OPTION VERSION "GCOS" ' GE 600 Mainframe BASIC + OPTION VERSION "HAARDT" ' bas 2.4 by Michael Haardt + OPTION VERSION "HANDBOOK1" ' The BASIC Handbook, 1st Edition + OPTION VERSION "HANDBOOK2" ' The BASIC Handbook, 2nd Edition + OPTION VERSION "HEATH" ' Heath Benton Harbor BASIC + OPTION VERSION "MARK-I" ' GE 265 Mainframe BASIC + OPTION VERSION "MARK-II" ' GE 435 Mainframe BASIC + OPTION VERSION "MBASIC" ' Microsoft BASIC-80 for Xenix + OPTION VERSION "PDP-8" ' DEC PDP-8 BASIC + OPTION VERSION "PDP-11" ' DEC PDP-11 BASIC + OPTION VERSION "RBASIC" ' Micronics RBASIC for 6809 FLEX + OPTION VERSION "RSTS-11" ' DEC RSTS-11 BASIC-PLUS + OPTION VERSION "SYSTEM/360" ' IBM System/360 Mainframe BASIC + OPTION VERSION "SYSTEM/370" ' IBM System/370 Mainframe BASIC + OPTION VERSION "TRS-80" ' TRS-80 Model I/III/4 LBASIC + OPTION VERSION "VINTAGE" ' Vintage BASIC 1.0.1 + OPTION VERSION "XBASIC" ' TSC XBASIC for 6800 FLEX + + For example, MOD is a function in OPTION VERSION "ECMA-116", + MOD is an operator in OPTION VERSION "MBASIC", and + MOD is a valid variable name in OPTION VERSION "CALL/360". + + The OPTION VERSION command also sets the following OPTION commands: + OPTION STRICT ON | OFF + OPTION ANGLE DEGREES | RADIANS | GRADIANS + OPTION BUGS ON | OFF + OPTION LABELS ON | OFF + OPTION COMPARE BINARY | DATABASE | TEXT + OPTION BASE integer + OPTION RECLEN integer + OPTION COVERAGE ON | OFF + OPTION TRACE ON | OFF + OPTION ERROR GOTO | GOSUB + OPTION DATE "format" + OPTION TIME "format" + OPTION PUNCT COMMENT "char" + OPTION PUNCT STATEMENT "char" + OPTION PUNCT PRINT "char" + OPTION PUNCT IMAGE "char" + OPTION PUNCT INPUT "char" + OPTION USING DIGIT "char" + OPTION USING COMMA "char" + OPTION USING PERIOD "char" + OPTION USING PLUS "char" + OPTION USING MINUS "char" + OPTION USING EXRAD "char" + OPTION USING DOLLAR "char" + OPTION USING FILLER "char" + OPTION USING LITERAL "char" + OPTION USING FIRST "char" + OPTION USING ALL "char" + OPTION USING LENGTH "char" + OPTION PUNCT QUOTE "char" + OPTION PUNCT STRING "char" + OPTION PUNCT DOUBLE "char" + OPTION PUNCT SINGLE "char" + OPTION PUNCT CURRENCY "char" + OPTION PUNCT LONG "char" + OPTION PUNCT INTEGER "char" + OPTION PUNCT BYTE "char" + OPTION PUNCT LPAREN "char" + OPTION PUNCT RPAREN "char" + OPTION PUNCT FILENUM "char" + OPTION PUNCT AT "char" + + The commands, functions, operators and settings for each BASIC dialect + is documented in the text files in the DOCS directory. + + OPTION DISABLE COMMAND + Disable a specific command. + + OPTION DISABLE FUNCTION + Disable a specific function. + + OPTION DISABLE OPERATOR + Disable a specific operator. + + OPTION ENABLE COMMAND + Enable a specific command. + + OPTION ENABLE FUNCTION + Enable a specific function. + + OPTION ENABLE OPERATOR + Enable a specific operator. + + OPTION ERROR GOSUB + The program will GOSUB to the error handler. + The error handler exits with the RETURN command. + + OPTION ERROR GOTO + The program will GOTO to the error handler. + The error handler exits with the RESUME command. + + OPTION LABELS OFF + Disables textual labels. + + OPTION LABELS ON + Enables textual labels. + + Regardless of the OPTION LABELS setting, statements of the form + IF x THEN label + are not allowed, instead use the form + IF x THEN GOTO label + The reason for this rule is because + IF x THEN y + is considered to be the same as + IF x THEN + y + END IF + where "y" is a command, function, or subroutine. Many BASIC dialects + that allow textual labels adopt this convention. + + OPTION ROUND controls how floating point values are converted to + whole number values. OPTION ROUNG MATH rounds toward the nearest + whole number, with halves rounding up to the next larger whole number, + as commonly expected by many scientific applications. OPTION ROUND + BANK rounds halves to the even whole numbers, as commonly expected + by many financial applications. OPTION ROUND TRUNCATE truncates to + the next smaller whole number, as commonly expected by many + applications written for an integer BASIC. The selected rounding + method is used whenever a whole number is required, including: + a) selection value for ON ... GOTO and ON ... GOSUB + b) any function parameter requiring a whole number + c) array subscripts and dimensions + d) string positions and lengths + e) CINT() and similar + The OPTION ROUND command does not change the results of INT() or FIX(). + The default rounding method is OPTION ROUND BANK. + + A comparison of the different OPTION ROUND settings upon the results of CINT() + + BANK MATH TRUNCATE + X int(X) fix(X) cint(X) cint(X) cint(X) + -2.0 -2 -2 -2 -2 -2 + -1.6 -2 -1 -2 -2 -1 + -1.5 -2 -1 -2 -2 -1 + -1.4 -2 -1 -1 -1 -1 + -1.0 -1 -1 -1 -1 -1 + -0.6 -1 0 -1 -1 0 + -0.5 -1 0 0 -1 0 + -0.4 -1 0 0 0 0 + 0.0 0 0 0 0 0 + 0.4 0 0 0 0 0 + 0.5 0 0 0 1 0 + 0.6 0 0 1 1 0 + 1.0 1 1 1 1 1 + 1.4 1 1 1 1 1 + 1.5 1 1 2 2 1 + 1.6 1 1 2 2 1 + 2.0 2 2 2 2 2 + + The OPTION BUGS command determines the behavior of a number of BASIC keywords. + BASIC programs which rely on these behaviors are non-portable and non-standard. + I have considered several different names for this command, but have not yet + thought of a better short name. + + OPTION BUGS ON disables the ANSI/ECMA/ISO standard behavior: + + FOR ... ' values are evaluated left-to-right + GOTO X OF ... ' an invalid value for X falls thru without ERROR + GOSUB X OF ... ' an invalid value for X falls thru without ERROR + ON X GOTO ... ' an invalid value for X falls thru without ERROR + ON X GOSUB ... ' an invalid value for X falls thru without ERROR + X = VAL("X") ' returns zero without ERROR + INPUT X ' empty string returns zero without ERROR + INPUT X$ ' empty string returns "" without ERROR + INPUT X$ ' allows unquoted character strings + variable names ' period and underscore are allowed + variable types ' the type characters #!@&% are allowed + PRINT "a" X ' string concatenation is implied + 1.2% is 1 ' the type characters #!@&% are allowed + 1D1 is ERROR ' 'D' is not allowed as exponent seperator + + OPTION BUGS OFF enables the ANSI/ECMA/ISO standard behavior: + + FOR ... ' values are evaluated according to standard + GOTO X OF ... ' an invalid value for X is an ERROR + GOSUB X OF ... ' an invalid value for X is an ERROR + ON X GOTO ... ' an invalid value for X is an ERROR + ON X GOSUB ... ' an invalid value for X is an ERROR + X = VAL("X") ' raises an illegal function call (ERROR 5) + INPUT X ' empty string retries input + INPUT X$ ' empty string retries input + INPUT X$ ' unquoted character strings retries input + variable names ' period and underscore are not allowed + variable types ' the type characters #!@&% are not allowed + PRINT "a";X ' string concatenation is not implied + 1.2% is ERROR ' the type characters #!@&% are not allowed + 1D1 is ERROR ' 'D' is not allowed as exponent seperator + + + 4.k. ERROR handling + + + bwBASIC implements a simplified error handling strategy. + Errors are seperated into two categories: + + a) Fatal errors. These errors include: + - Unknown command + - FOR without NEXT + - NEXT without FOR + - WHILE without WEND + - WEND without WHILE + - and so on. + The program is scanned prior to running and if any of these errors is + detected, then the program is not allowed to run. If these errors + occur as the result of a DELETE or MERGE in a running program, then the + program is terminated. + + b) Non-fatal errors. If an error handler exists, then it is executed, + otherwise the default behaivor is performed. The correct action to + take in an error handler depends upon the specific application. + - Overflow (ERROR 6) + - the default behavior is to display a warning message. + - Division by zero (ERROR 11) + - the default behavior is to display a warning message. + - String too long (ERROR 15) + - the default behavior is to display a warning message. + - All other non-fatal errors + - the default behavior is to terminate the program. + + bwBASIC 2.61 used ON ERROR GOSUB for error trapping. + This version defaults to ON ERROR GOTO instead. + + + 4.l. Implementation rules for functions and commands + + + In many BASIC dialects, keywords are seperated into three distinct groups: + Commands, Statements, and Functions. In bwBASIC, keywords are seperated + into only two groups: Commands and Functions. A keyword documented as a + Command or Statament in a specific BASIC dialect may have been implemented + in bwBASIC as a Function. This is merely an implementation decision, which + may change in the future. Each keyword should only be used as described in + the reference document. The following rules are considered when deciding + whether a BASIC keyword is implemented as a command or a function: + + a) If the keyword requires significant parsing, + then it is implemented as a command. An example is "PRINT". + + b) If the keyword requires access to variables BYREF, + then it is implemented as a command. An example is "SWAP". + + c) If the keyword changes the flow of control, + then it is implemented as a command. An example is "GOTO". + + d) A function may be used as though it were a command, + but a command cannot be used as though it were a function. + + e) The BASIC program can redefine a function, + but the BASIC program cannot redefine a command. + + f) The BASIC program can overload a function, + but the BASIC program cannot overload a command. + + g) Other than semantics, there is no practical difference + between a BASIC function and a BASIC subroutine. The + return value of a BASIC subroutine, when called as a + function, is zero. Calling a BASIC function as if it + were a subroutine simply discards the return value. + + These rules were chosen to maintain compatibility with + many BASIC dialects. + + An example of the results of the above rules is "OUT". + Since "OUT" is implemented as a function, you may: + a) call it as a subroutine like this: + 100 OUT X, Y + b) call it as a function like this: + 100 LET N = OUT( X, Y ) ' N = 0 + c) redefine it as a subroutine like this: + SUB OUT( X, Y ) + REM ... + END SUB + d) redefine it as a function like this: + FUNCTION OUT( X, Y ) + REM ... + END FUNCTION + e) overload it using subroutines like these: + SUB OUT( X, Y ) + REM ... + END SUB + SUB OUT( X, A$ ) + REM ... + END SUB + SUB OUT( A$, X ) + REM ... + END SUB + SUB OUT( A$, B$ ) + REM ... + END SUB + f) overload it using functions like these: + FUNCTION OUT( X, Y ) + REM ... + END FUNCTION + FUNCTION OUT( X, A$ ) + REM ... + END FUNCTION + FUNCTION OUT( A$, X ) + REM ... + END FUNCTION + FUNCTION OUT( A$, B$ ) + REM ... + END FUNCTION + + + 4.m. Reference documentation + + + bwBASIC is preconfigured to support a number of specific BASIC dialects which were + implemented using the following references, however bwBASIC does not attempt to be + bug-level compatible and does not implement non-portable design choices. A manual + for each dialect is in the DOCS directory to make you aware that a specific keyword + is implemented, however you should refer to the reference document for a proper + understanding of how to use each keyword. There are many other good books which + describe these BASIC dialects in detail. + + OPTION VERSION "BYWATER" ' Bywater BASIC 3 + MANUAL: + BYWATER.TXT + + OPTION VERSION "BYWATER-2" ' Bywater BASIC 2 + MANUAL: + BYWATER-2.TXT + NOT IMPLEMENTED: + DO NUM, DO UNNUM + NOTES: + SUB MAIN is not automatically called. + CALL requires parentheses around the function/subroutine parameters, + so instead of + CALL abc 1, 2, 3 + use + CALL abc( 1, 2, 3 ) + + OPTION VERSION "CALL/360" ' SBC CALL/360 Mainframe BASIC + MANUAL: + CALL-360.TXT + NOT IMPLEMENTED: + MAT PRINT USING. + NOTES: + The APPENDIXES are implementation specific and are not supported. + + OPTION VERSION "CBASIC-II" ' CBASIC-II for CP/M + MANUAL: + CBASIC-II.TXT + ADDITIONAL INFORMATION: + "CBASIC Language Reference Manual, 2nd Edition" + by Diigital Research + (c) 1982, Diigital Research + http://bitsavers.trailing-edge.com/pdf/digitalResearch/cb80/ + CBASIC_Language_Reference_Manual_Oct82.pdf + NOT IMPLEMENTED: + CONSTAT%, CONCHAR% and compiler directives. + NOTES: + The APPENDIXES are implementation specific and are not supported. + The %INCLUDE directive is implemented, but only supports literal + unquoted filesnames without drive or directory, such as: + %INCLUDE LIBRARY.BAS + Note that the %INCLUDE directive is executed as a file is being loaded, + and as a result the %INCLUDE does not appear in the resulting listing. + Machine language functions and commands are not supported. + The parsing of command line parameters is implementation defined. + The specification of an array in a COMMON statement is the same as + the specification in a DIM statement. + The SIZE() function assumes 1024 bytes and does not support wild-cards; + if the file does not exist then SIZE() returns zero, otherwise SIZE() + returns the number of 1024 bytes blocks required to contain the file; + an existing file of zero bytes returns a value of 1. + + OPTION VERSION "DARTMOUTH" ' Dartmouth DTSS BASIC + MANUAL: + DARTMOUTH.TXT + NOTES: + The APPENDICES are implementation specific and are not supported. + Sections 4.2 and 4.3 are implementation specific and are not supported. + Lines containing data to be READ must have a line number and a DATA command. + NOT IMPLEMENTED: + Card punch codes are not supported, use a comma or semicolon instead. + + OPTION VERSION "ECMA-55" ' ANSI Minimal BASIC + MANUAL: + ECMA-55.TXT + NOTES: + The APPENDICES are implementation specific and are not supported. + DIM is an executed statement in bwBASIC. + This is a design decision to support the following example. + 100 INPUT "How many?"; N + 110 DIM A$(N) + + OPTION VERSION "ECMA-116" ' ANSI Full BASIC + MANUAL: + ECMA-116.TXT + NOT IMPLEMENTED: + Graphic commands, chapters 11 thru 15. + NOTES: + The APPENDICES are implementation specific and are not supported. + WORK-IN-PROGRESS. + + OPTION VERSION "GCOS" ' GE 600 Mainframe BASIC + MANUAL: + GCOS.TXT + NOT IMPLEMENTED: + HPS, LIN, RESTORE*, RESTORE$, VPS and binary files. + NOTES: + The APPENDIXES are implementation specific and are not supported. + Local variables in a multiline DEF are declared using DIM. + Line numbers are not written to, nor read from, data files. + FILES does not support passwords. + Literal values for file names are not supported, use string values instead. + This is a design decision to support the following: + 100 INPUT "Which files?"; A$, B$, C$ + 110 FILES A$, B$, C$ + + OPTION VERSION "HAARDT" ' bas 2.4 by Michael Haardt + MANUAL: + HAARDT.TXT + NOT IMPLEMENTED: + BBC syntax, use ANSI syntax instead. + ON ERROR statement(s) is not supported, use ON ERROR GOTO instead. + ON ERROR OFF, use ON ERROR GOTO 0 instead. + MAT REDIM, OPTION RUN, OPTION STOP, TRUNCATE, UNNUM and XREF. + DEC$(X,A$), ENVIRON$(X), FIND$(A$[,X]) and INSTR(A$,B$,X,Y). + NOTES: + POS and TAB are 1-based instead of 0-based. + ON ERROR GOTO 0 does not cause any error to occur, instead + ON ERROR GOTO 0 removes the current error handler and clears + ERL, ERR and ERROR$. + + OPTION VERSION "HANDBOOK1" ' The BASIC Handbook, 1st Edition + MANUAL: + HANDBOOK1.TXT + NOT IMPLEMENTED: + Abbreviated commands (such as A.) and graphic commands. + NOTES: + The APPENDICES are implementation specific and are not supported. + The ERR function returns different values. + + OPTION VERSION "HANDBOOK2" ' The BASIC Handbook, 2nd Edition + MANUAL: + HANDBOOK2.TXT + NOT IMPLEMENTED: + Abbreviated commands (such as A.) and graphic commands. + NOTES: + The APPENDICES are implementation specific and are not supported. + The ERR function returns different values. + + OPTION VERSION "HEATH" ' Heath Benton Harbor BASIC + NOT IMPLEMENTED: + FREEZE, UNFREEZE, LOCK, UNLOCK, STEP + NOTES: + The APPENDICES are implementation specific and are not supported. + PRINT #-1 is sent to the printer. + INPUT #-1 is an ERROR. + + OPTION VERSION "MARK-I" ' GE 265 Mainframe BASIC + MANUAL: + MARK-I.TXT + ADDITIONAL REFERENCE: + "Time-Sharing Service BASIC LANGUAGE EXTENSIONS Reference Manual" + by Time-Sharing Service, Information Service Department, General Electric + (c) 1968, General Electric Company and Trustees of Dartmouth College + http://www.bitsavers.org/pdf/ge/MarkI_Timesharing/ + 802207A_Time-SharingServiceBASICLanguageExtensionsReferenceManual_Feb1968.pdf + NOTES: + The APPENDIXES are implementation specific and are not supported. + NOT IMPLEMENTED: + A series of variables seperated by equal signs is not supported, + use a series of variables seperated by commas instead. + Literal values for file names are not supported, use string values instead. + This is a design decision to support the following: + 100 INPUT "Which files?"; A$, B$, C$ + 110 FILES A$, B$, C$ + CALL, to execute another compiled program, is not supported, use SHELL instead. + + OPTION VERSION "MARK-II" ' GE 435 Mainframe BASIC + MANUAL: + MARK-II.TXT + ADDITIONAL INFORMATION: + "Basic Software Library" (Volumes 1 to 8) + by R. W. Brown + (c) 1977, Scientific Research Inst. + NOT IMPLEMENTED: + HPS, LIN, RESTORE*, RESTORE$, VPS and binary files. + NOTES: + The APPENDIXES are implementation specific and are not supported. + Local variables in a multiline DEF are declared using DIM. + Line numbers are not written to, nor read from, data files. + Literal values for file names are not supported, use string values instead. + This is a design decision to support the following: + 100 INPUT "Which files?"; A$, B$, C$ + 110 FILES A$, B$, C$ + FILES does not support passwords. + + OPTION VERSION "MBASIC" ' Microsoft BASIC-80 for Xenix + MANUAL: + MBASIC.TXT + NOTES: + The APPENDICES are implementation specific and are not supported. + The ERR function returns different values. + Specifying "D" in the exponent is not supported, instead use "E". + + OPTION VERSION "PDP-8" ' DEC PDP-8 BASIC + MANUAL: + PDP-8.TXT + NOT IMPLEMENTED: + NO RUBOUTS, RUBOUTS + NOTES: + The APPENDICES are implementation specific and are not supported. + + OPTION VERSION "PDP-11" ' DEC PDP-11 BASIC + MANUAL: + PDP-11.TXT + NOTES: + The APPENDICES are implementation specific and are not supported. + + OPTION VERSION "RBASIC" ' Micronics RBASIC for 6809 FLEX + MANUAL: + RBASIC.TXT + NOT IMPLEMENTED: + "+" command, COMPILE, CVT$, CVTF$, CVT$%, CVT$F + NOTES: + The APPENDICES are implementation specific and are not supported. + The ERR function returns different values. + + OPTION VERSION "RSTS-11" ' DEC RSTS-11 BASIC-PLUS + MANUAL: + RSTS-11.TXT + ADDITIONAL INFORMATION: + "BASIC-PLUS Language Manual : for use with RSTS-11 (PDP-11 Resource Time-Sharing System)" + by Digital Equipment Corporation + (c) 1972, Digital Equipment Corporation + http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rsts/V04/ + DEC-11-ORBPA-A-D_BASIC-PLUS_LangMan_Oct72.pdf + ADDITIONAL INFORMATION: + "PDP-11 : BASIC-PLUS Language Manual" + by Digital Equipment Corporation + (c) 1975, Digital Equipment Corporation + http://bitsavers.trailing-edge.com/pdf/dec/pdp11/rsts/V06/ + DEC-11-ORBPB-A-D_BASIC-PLUS_LangMan_Jul75.pdf + NOT IMPLEMENTED: + HELLO, RENAME, REPLACE, COMPILE, LENGTH, TAPE, KEY, ASSIGN, DEASSIGN. + FOR ... WHILE, FOR ... UNTIL, statement modifiers. + NOTES: + The APPENDIXES are implementation specific and are not supported. + The ERR function returns different values. + The statemnet NAME ... AS does not support the <protection> specifier. + + OPTION VERSION "SYSTEM/360" ' IBM System/360 Mainframe BASIC + MANUAL: + SYSTEM-360.TXT + ADDITIONAL INFORMATION: + "IBM System/360 0S(TS0) ITF:BASIC Terminal User's Guide" + by International Business Machines Corporation + (c) 1971, International Business Machines Corporation + http://bitsavers.org/pdf/ibm/360/os/tso/ + SC28-6840-0_TSO_ITF_BASIC_Terminal_UG_Apr71.pdf + NOT IMPLEMENTED: + MAT PRINT USING. + NOTES: + The APPENDIXES are implementation specific and are not supported. + + OPTION VERSION "SYSTEM/370" ' IBM System/370 Mainframe BASIC + MANUAL: + SYSTEM-370.TXT + NOT IMPLEMENTED: + MAT PRINT USING. + NOTES: + The APPENDIXES are implementation specific and are not supported. + + OPTION VERSION "TRS-80" ' TRS-80 Model I/III/4 LBASIC + MANUAL: + TRS-80.TXT + NOT IMPLEMENTED: + CMD, SET EOF, cassette I/O. + NOTES: + The APPENDICES are implementation specific and are not supported. + The ERR function returns different values. + For the TRS-80 Model I use "WIDTH 16,64" in "profile.bas". + For the TRS-80 Model III use "WIDTH 16,64" in "profile.bas". + For the TRS-80 Model 4 use "WIDTH 24,80" in "profile.bas". + bwBASIC requires a space around all keywords, so the LINEINPUT + command must be written as LINE INPUT, and so on. + PRINT #-1 is sent to the printer. + INPUT #-1 is an ERROR. + + OPTION VERSION "VINTAGE" ' Vintage BASIC 1.0.1 + MANUAL: + VINTAGE.TXT + NOTES: + The APPENDICES are implementation specific and are not supported. + + OPTION VERSION "XBASIC" ' TSC XBASIC for 6800 FLEX + MANUAL: + XBASIC.TXT + NOT IMPLEMENTED: + "+" command, COMPILE, CVT$, CVTF$, CVT$%, CVT$F + NOTES: + The APPENDICES are implementation specific and are not supported. + The ERR function returns different values. + + +5. PREDEFINED VARIABLES - no longer exist + + + BWB.EDITOR$ + BWB.FILES$ + BWB.PROMPT$ + BWB.IMPLEMENTATION$ + + These preset variables no longer exist in bwBASIC. They have + been replaced with OPTION EDIT, OPTION FILES and OPTION PROMPT + commands. + + The commands EDIT and FILES are pseudo-commands that launch + shell programs set by OPTION EDIT and OPTION FILES commands, + respectively. The default values for these commands can + be changed in bwBASIC.h (DEF_EDITOR and DEF_FILES), and they + can be changed on the fly by the user. It is expected that + the user will add the appropriate commands to "profile.bas" + for their specific implementation; OPTION FILES "ls -l" on Unix + systems and OPTION FILES "dir" on DOS systems. + + The command OPTION PROMPT can be used to set the prompt + string for bwBASIC. Again, it is suggested that a user- + selected prompt can be set up in a "profile.bas" to be + initialized each time bwBASIC starts. Note that special + characters can be added to the prompt string, e.g., + + OPTION PROMPT "Ok"+CHR$(10) + + will give an "Ok" prompt followed by a linefeed. + + In previous versions, the preset variable BWB.IMPLEMENTATION$ + would return "TTY" (IMP_IDSTRING) for the bwx_tty implementation. + In previous versions of bwBASIC, the existance of the keywords CLS, + COLOR and LOCATE were determined at compile and BWB.IMPLEMENTATION$ + was used at runtime to determine whether these keywords existed. + In the current version, these keywords always exist and are now + controlled at runtime using the OPTION TERMINAL commands. With + OPTION TERMINAL NONE these keywords output nothing. + + +6. UNIMPLEMENTED COMMANDS AND FUNCTIONS, and AGENDA FOR DEVELOPMENT + + + There are some items not implemented that have been so long + a part of some BASIC dialects that their absence may seem surprising. + In each case, though, their implementation would require + operating-system-specific functions or terminal-specific functions + that cannot be universally provided. Some specific examples are + detailed below. + + + INP reads a value from a hardware port. In the current version, + using INP() will generate ERROR 73. It is expected that you will + provide a suitable implementation for your specific application. + For example: + FUNCTION INP( X ) + REM Return whatever value your application requires + INP = 0 + END FUNCTION + + + OUT writes a value to a hardware port. In the current version, + using OUT() will generate ERROR 73. It is expected that you will + provide a suitable implementation for your specific application. + For example: + SUB OUT( X, Y ) + REM do whatever your application requires + END SUB + + + PEEK reads a value from a memory location. In the current version, + using PEEK() will generate ERROR 73. It is expected that you will + provide a suitable implementation for your specific application. + For example: + FUNCTION PEEK( X ) + REM Return whatever value your application requires + PEEK = 0 + END FUNCTION + + + POKE writes a value to a memory location. In the current version, + using POKE() will generate ERROR 73. It is expected that you will + provide a suitable implementation for your specific application. + For example: + SUB POKE( X, Y ) + REM do whatever your application requires + END SUB + + + WAIT reads a value from a hardware port. In the current version, + using WAIT() will generate ERROR 73. It is expected that you will + provide a suitable implementation for your specific application. + For example: + SUB WAIT( X, Y ) + REM do whatever your application requires + END SUB + SUB WAIT( X, Y, Z ) + REM do whatever your application requires + END SUB + + + USR executes a machine code routine. In the current version, + using USR() will generate ERROR 73. It is expected that you will + provide a suitable implementation for your specific application. + For example: + FUNCTION USR( ... ) + REM Return whatever value your application requires + USR = 0 + END FUNCTION + + + VARPTR reads a value from a memory location. In the current version, + using VARPTR() will generate ERROR 73. It is expected that you will + provide a suitable implementation for your specific application. + For example: + FUNCTION VARPTR( ... ) + REM Return whatever value your application requires + VARPTR = 0 + END FUNCTION + + + There are other commands, functions, and implementation details + that I am working on, and which are on the agenda list for future + versions of bwBASIC. These agenda include: + + + PARACT i.e., the ability to execute PARallel ACTions. This + is described in ANSI BASIC, although I have not seen it + implemented before. It will offer a rough, non-preemptive + form of multitasking within the scope of a BASIC program. + Programmers will note that the global My pointer provides + one possible hook mechanism for PARACT in bwBASIC. In the + interim, you might use the "ON TIMER" command to implement + a simple multitasking BASIC program. + + + XMEM PC-type computers usually are able to use extended + memory. If we could use extended memory for program + lines, variables, and function defitions, we could + write much longer programs. This would entail, + however, a fairly serious rewriting of the program + to utilize memory handles for these storage features + instead of direct memory pointers. In the interim, + you might use a "DOS Extender" which hooks calloc() + and free() to enable transparent access to EMS or XMS + memory. + + + Windows The addition of memory handles in addition to the + non-preemptive execution of program lines (in a + crude form, already present) will make it possible + to develop implementations for Windows and perhaps + for other graphical user interfaces. But what form + should this take? I have in mind presently a BASIC + that would run in the background, appearing only + as an icon in the GUI space, with pop-up editors + and output windows. Thus, the interpreted language + would serve a purpose something like 'cron' (a task + scheduler) under Unix systems. You may have some + reflections that would help me in this. + + + Graphics Here we face fairly critical differences in different + styles and implementations of graphics, e.g., between + GWBASIC, ANSI BASIC, VisualBASIC, etc. But it's + possible that Graphics commands and functions could + be added. These would all be OPTION VERSION specific. + In the interim, you might consider using ReGIS or Tektronix + graphics (ESC codes) with xterm. + + + The ANSI Standard for full BASIC does not specify which particular + commands or functions must be implemented, and in fact the standard + is very robust. Perhaps no implementation of BASIC would ever + include all of the items, but some ANSI commands and functions which + remain unimplemented are: + + ACCESS + AREA + ARRAY + ASK + BSTR + BVAL + CELLS + CLIP + COLLATE + CONNECT + DATUM + DEBUG + DECLARE + DEVICE + DISCONNECT + DISPLAY + DOT + DRAW + ERASE + EVENT + EXCEPTION + GRAPH + HANDLER + IMAGE + KEY + LINES + MIX + MULTIPOINT + OUTIN + OUTPUT + PARACT + PICTURE + PIXEL + PLOT + POINTS + RECEIVE + RENUMBER + REWRITE + ROTATE + SEIZE + SEND + SHIFT + TIMEOUT + TRACE + TRANSFORM + VIEWPORT + WAIT + VIEWPORT + ZONEWIDTH + + +7. THE STORY OF Bywater BASIC + + + This program was originally begun in 1982 by my grandmother, Mrs. + Verda Spell of Beaumont, TX. She was writing the program using + an ANSI C compiler on an Osborne I CP/M computer and although my + grandfather (Lockwood Spell) had bought an IBM PC with 256k of + RAM my grandmother would not use it, paraphrasing George Herbert + to the effect that "He who cannot in 64k program, cannot in 512k." + She had used Microsoft BASIC and although she had nothing against + it she said repeatedly that she didn't understand why Digital + Research didn't "sue the socks off of Microsoft" for version 1.0 + of MSDOS and so I reckon that she hoped to undercut Microsoft's + entire market and eventually build a new software empire on + the North End of Beaumont. Her programming efforts were cut + tragically short when she was thrown from a Beaumont to Port + Arthur commuter train in the summer of 1986. I found the source + code to bwBASIC on a single-density Osborne diskette in her knitting + bag and eventually managed to have it all copied over to a PC + diskette. I have revised it slightly prior to this release. You + should know, though, that I myself am an historian, not a programmer. + + +8. COMMUNICATIONS: + + + email: tcamp@delphi.com + + +9. EXPANDED REFERENCE FOR COMMANDS, FUNCTIONS AND OPERATORS + + + bwBASIC provides a simple "HELP" command to refresh your memory + regarding the appropriate syntax for a specific command or function. + In the DOCS directory are text files which provide brief descriptions + of every intrinsic command, function and operator available in BASIC + dialect available in bwBASIC; these files are not intented to be an + authoritative or exhaustive reference. Refer to the reference document + for each dialect for details regarding each keyword. + + +THE END |