Data update

Task/Variables/S-BASIC/variables.basic

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+COMMENT
+  Variables are of six types, with arrays of each type being supported:
+
+    CHAR (or BYTE)              FIXED
+    STRING                      REAL
+    INTEGER                     REAL.DOUBLE
+
+  Simple variables may be declared using the VAR, COMMON, and BASED keywords.
+
+  Arrays are declared using the DIM keyword and, if applicable, the COMMON or
+  BASE keyword. The maximum length of a string variable may be specified as
+  part of the declaration; if omitted, the default length is 80. Examples follow:
+
+    VAR FN = STRING:15
+    VAR X, Y, Z = INTEGER
+    VAR RATE = REAL
+
+    BASED IOBYTE = BYTE
+    COMMON ERROR_NUMBER = INTEGER
+
+    DIM REAL TEMPERATURES(20)
+    DIM INTEGER MATRIX(4,4)
+    DIM STRING:20 LASTNAMES(100)
+    DIM BASE BYTE FCB(16)
+    DIM COMMON INTEGER HISCORES(10)
+
+  Simple variables declared with VAR are placed in the data segment of the
+  compiled code.  Variables declared COMMON are placed in a special data
+  segment that will be preserved during program chaining. Variables
+  declared using the BASED statement are positioned at run-time
+  using the BASE statement to specify the address, e.g.,
+
+     BASE IOBYTE AT 0003H
+
+  Arrays are dynamically created at run-time and do not occupy space in the
+  compiled code unless they are declared as COMMON.  Arrays declared as BASE
+  are positioned at run-time using the LOCATE statement, e.g.,
+
+     LOCATE FCB AT 5CH
+
+  CHAR or BYTE variables occupy 1 byte.  Character constants may be specified
+  using single quotes, e.g., 'A', or in decimal or hexadecimal form, e.g., 64
+  or 40H.
+
+  INTEGER variables occupy 2 bytes and may take signed decimal values from
+  -32768 to +32767 or unsigned hexadecimal values from 0000H to FFFFH.
+
+  FIXED variables occupy 6 bytes and can represent a sign and 11 digits in
+  packed BCD form, with 3 digits to the right of the decimal point. The
+  maximum value that can be represented is 99,999,999.995.
+
+  REAL variables occupy 4 bytes and can represent floating point values up
+  to 6 digits. Constants may be expressed as, e.g., 3.14159 or 3.14159E+1.
+
+  REAL.DOUBLE variables occupy 7 bytes and can represent floating point values
+  up to 12 digits.
+END