int e l 1.4 DEFINITION OF TERMS RELATIONAL EXPRESSIONS: Relational expressions involve the operators EQUAL (=), NOT EQUAL ( ), GREATER THAN (>), LESS THAN ( =) and LESS THAN OR EQUAL TO ( They are used in control statements to "test" a condition (i.e. IF A expressions ALWAYS REQUIRE TWO OPERANDS. This document will refer to RELATIONAL EXPRESSIONS as: [rel expr]. SPECIAL FUNCTION OPERATORS: Virtually all of the special function registers on the 8052AH can be accessed by using the special function operators. The exceptions are PORTS 0, 2 and 3 and non-I/O associated registers such as ACC, B, and PSW. Other SPECIAL FUNCTION OPERATORS are XTAL and TIME.
Details of the SPECIAL FUNCTION OPERATORS are covered in the section SPECIAL FUNCTION OPERATORS. SYSTEM CONTROL VALUES: The system control values include the following: LEN (which returns the length of the program), FREE (which designates how many bytes of RAM are not used that are allocated to BASIC), and MTOP (which is the last memory location that is assigned to BASIC). Details of the system control values are covered in the section SYSTEM CONTROL VALUES. - 7 -