SuperBASIC Name Table

The Name Table consists of a number of eight byte rows, each in the following form:

Type Offset Value pointer

  • The first word is a code giving the Type.

  • This is followed by another word which is the offset from the start of the Name List to the associated name, or -1 if there is no associated name, which is the case for an expression and a substring.

  • Finally there is a long word containing a value pointer which can be one of four things:

    • An offset into the variables area.
    • A pointer to the maths stack.
    • A SuperBASIC line number held in the high word.
    • An Absolute address.

Type Codes

Type Description Value pointer to …
$0001 Unset string Variables area
$0002 Unset fp Variables area
$0003 Unset integer Variables area
$0101 String expression Maths stack
$0102 Fp expression Maths stack
$0103 Integer expression Maths stack
$0201 String Variables area
$0202 Fp number Variables area
$0203 Integer Variables area
$0300 Substring Variables area
$0301 String array Variables area
$0302 Fp array Variables area
$0303 Integer array Variables area
$0400 SuperBASIC procedure SuperBASIC line number
$0501 SuperBASIC string function SuperBASIC line number
$0502 SuperBASIC fp function SuperBASIC line number
$0503 SuperBASIC integer function SuperBASIC line number
$0602 REPeat loop index Variables area
$0702 FOR loop index Variables area
$0800 Machine code procedure Procedure address in RAM
$0900 Machine code function Function address in RAM

Parameters

When a machine code routine is called the parameters are put into the Name Table. In this case the Type code contains information about the parameters.

  • Bit 7 is set if the parameter is preceded by ‘#’ (hash).
  • Bits 6 to 4 contain the Separator type.
  • Bits 3 to 0 contain the Type of the parameter.
Bit 7 Hash prefix? Bits 6 to 4 Separator Bits 3 to 0 Type
%0 No hash %000 None %0000 Null
%1 Hash %001 , %0001 String
%010 ; %0010 Floating Point
%011 \ %0011 Integer
%100 !
%101 TO

Updated on 28 Dec 2018