134,135



        racters < 128
     30   NUM = 0: FOR VARI = PEEK(130) +
        PEEK(313) * 256 TO PEEK(132) + PEE
        K(131) * 256 - 1:NUM = NUM + (PEEK
        (VARI) < 127):NEXT VARI: PRINT NU
        M; "Variables in use"

Or try this, for a possibly less opaque example of the same
routine:

     1000  NUM = 0: FOR LOOP = PEEK (130) +
           PEEK(131) * 256 TO PEEK(132) +
           PEEK(133) * 256 - 1
     1010  IF PEEK(LOOP) < 128 THEN PRINT
          CHR$(PEEK(LOOP));: GOTO 1030
     1020  PRINT CHR$(PEEK(LOOP) - 128): N
          UM - NUM + 1
     1030  NEXT LOOP: PRINT; PRINT NUM; "
          VARIABLES IN USE": END

134,135        86,87          VVTP
     Address for the variable value table. Eight bytes are allocated for
     each variable in the name table as follows:

     Byte              1         2     3  4     5     6    7      8
     Variable
     --------------------------------------------------------------
     Scalar           00     var #     six byte BCD constant
     Array;DIMed      65     var #     offset     first     second
         unDIMed      64               from       DIM + 1   DIM + 1
                                       STARP
     String;DIMed    129     var #     offset     length    DIM
          unDIMed    128               from
                                       STARP

     In scalar (undimensioned numeric) variables, bytes three to eight
     are the FP number; byte three is the exponent; byte four contains
     the least significant two decimal digits, and byte eight contains
     the most significant two decimal digits.
     In array variables, bytes five and six contain the size plus one of
     the first dimension of the array (DIM + 1; LSB/MSB), and bytes
     seven and eight contain the size plus one of the second dimension
     (the second DIM + 1; LSB/MSB).
     In string variables, bytes five and six contain the current length
     of the variable (LSB MSB), and bytes seven and eight contain the
     actual dimension (up to 32767). There is an undocumented
     BASIC statement, "COM," mentioned only in the BASIC
     Reference Manual's index, which executes exactly the same as