Ye Ol' π Shack

* Implements most of the following BASIC dialects:
    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

 * CONST variable [, ...] = value
    Assigns the value to variable.
    Any later assignment to the variable causus a VARIABLE NOT DECLARED error.

 * DIM now supports lower and upper bounds.
    OPTION BASE 1
    DIM X(      9 ) ' lower bound is 1
    DIM Y( 5 TO 9 ) ' lower bound is 5

 * DIM now supports virtual variables.
    OPTION BASE 1
    OPEN "VIRTUAL.DAT" FOR VIRTUAL AS # 3 ' virtual data file
    DIM # 3, A( 1000 )        ' array is virtual
    LET A( 1000 ) = 0         ' value is written to the file
    LET X = A( 1000 )         ' value is read from the file
    CLOSE # 3                 ' array is no longer valid

 * ERROR 27, "Bad DATA"
    Occurs when the READ command detects garbage in a DATA command.

 * INPUT LINE
    Same as LINE INPUT.

 * MAT now supports lower and upper bounds.
    OPTION BASE 1
    MAT X(      9 ) = ZER ' lower bound is 1
    MAT Y( 5 TO 9 ) = ZER ' lower bound is 5
    MAT X = ZER(      9 ) ' lower bound is 1
    MAT Y - ZER( 5 TO 9 ) ' lower bound is 5

 * MAXLEN()
   Returns the maximum string length.

 * OPTION DIGITS integer
    Sets the number of significant digits for PRINT.
    Setting the value to zero restores the default.

 * OPTION EDIT string$
    Sets the program name used by the EDIT command.
    Setting this to "" disables EDIT command.

 * OPTION FILES string$
    Sets the program name used by the FILES command.
    Setting this to "" disables FILES command.

 * OPTION PROMPT string$
    Sets the prompt.

 * OPTION PUNCT AT char$
    Sets the PRINT AT character, commonly "@".
    Setting this to "" disables PRINT AT.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT BYTE char$
    Sets the BYTE type suffix, commonly "~".
    Setting this to "" disables BYTE suffix.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT COMMENT char$
    Sets the trailing COMMENT character, commonly "'".
    Setting this to "" disables trailing comments.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT CURRENCY char$
    Sets the CURRENCY type suffix, commonly "@".
    Setting this to "" disables CURRENCY suffix.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT DOUBLE char$
    Sets the DOUBLE type suffix, commonly "#".
    Setting this to "" disables DOUBLE suffix.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT FILENUM char$
    Sets the FILE NUMBER prefix, commonly "#".
    Setting this to "" disables the FILE NUMBER prefix.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT IMAGE char$
    Sets the shortcut IMAGE character, commonly ":".
    Setting this to "" disables the shortcut IMAGE character.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT INPUT char$
    Sets the shortcut INPUT character, commonly "!".
    Setting this to "" disables the shortcut INPUT character.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT INTEGER char$
    Sets the INTEGER type suffix, commonly "%".
    Setting this to "" disables INTEGER suffix.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT LONG char$
    Sets the LONG type suffix, commonly "&".
    Setting this to "" disables LONG suffix.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT LPAREN char$
    Sets the LEFT PARENTHESIS character, commonly "(".
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT PRINT char$
    Sets the shortcut PRINT character, commonly "?".
    Setting this to "" disables the shortcut PRINT character.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT QUOTE char$
    Sets the QUOTE character, commonly """".
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT RPAREN char$
    Sets the RIGHT PARENTHESIS character, commonly ")".
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT SINGLE char$
    Sets the SINGLE type suffix, commonly "!".
    Setting this to "" disables SINGLE suffix.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT STATEMENT char$
    Sets the shortcut STATEMENT seperator character, commonly ":".
    Setting this to "" disables the STATEMENT seperator.
    Setting this to a non-punctuation character is not supported.

 * OPTION PUNCT STRING char$
    Sets the STRING type suffix, commonly "$".
    Setting this to "" disables STRING suffix.
    Setting this to a non-punctuation character is not supported.

 * OPTION RECLEN integer
    Sets the default record length for RANDOM files, commonly 128.
    Setting thisto zero means there is no default RANDOM record
    length, so the record  length must be specified in the OPEN
    statement.
    With OPTION RECLEN 128:
       OPEN "FILE.DAT" FOR RANDOM AS #3
    is considered to be the same as
       OPEN "FILE.DAT" FOR RANDOM AS #3 LEN 128
    With OPTION RECLEN 0:
       OPEN "FILE.DAT" FOR RANDOM AS #3
    causes an error.

 * OPTION RENUM string$
    Sets the program name used by the RENUM command.
    Setting this to "" disables RENUM command.

 * OPTION SCALE integer
    Sets the number of digits to round after the decimal point for PRINT.
    Setting the value to zero disables rounding.

 * OPTION USING DIGIT
 * OPTION USING COMMA
 * OPTION USING PERIOD
 * OPTION USING PLUS
 * OPTION USING MINUS
 * OPTION USING EXRAD
 * OPTION USING DOLLAR
 * OPTION USING FILLER
 * OPTION USING LITERAL
 * OPTION USING FIRST
 * OPTION USING ALL
 * OPTION USING LENGTH
    Sets the characters recognized by PRINT USING.
    Setting these to a non-punctuation character is not supported.

 * OPTION VERSION now requires a string instead of a literal.
    Some version names have changed.

 * OPTION VERSION "PDP-8"
    Added LPT, PTP, PTR, TTY, TTY IN and TTY OUT commands.
    Added GET() and PUT() functions.

 * OPTION VERSION "CALL/360"
 * OPTION VERSION "SYSTEM/360"
 * OPTION VERSION "SYSTEM/370"
    Added alphabet extenders.  $ is a string variable.

 * OPTION ZONE integer
    Sets the PRINT zone width.
    Setting the value to zero restores the default.

 * REPEAT - UNTIL added
    REPEAT
      ...
      EXIT REPEAT
      ...
    UNTIL expression ' exits when expression != 0

 * SPC( X ) and TAB( X )
    No longer use control codes.

 * UNTIL - UEND removed (to add REPEAT - UNTIL)
   Here is a work-around for existin code using UNTIL-UEND:
    UNITL expression -->> WHILE NOT expression
      ...                   ...
      EXIT UNTIL     -->>   EXIT WHILE
      ...                   ...
    UEND             -->> WEND

 * from Howard Wulf, AF5NE

Editor's Note: In the official release *ALL* of the test and sample
  BASIC programs were removed and packaged in a separate "test" ZIP. I
  have extracted those in to the bwbtest folder where most of the
  tests were living in previous packages. I've also improved (I hope)
  the EOL handling.
    - ChipMaster