TAL Programmer's Guide

Glossary
Glossary–2 096254 Tandem Computers Incorporated
bit shift. The shifting of bits within an INT or INT(32) expression a specified number of
positions to the left or right. An INT expression can consist of STRING, INT, or
UNSIGNED(1–16) values. An INT(32) expression can consist of INT(32) or
UNSIGNED(17–31) values.
bit-shift operators. Unsigned ('<<', '>>') or signed (<<, >>) operators that left shift or
right shift a bit field within an INT or INT(32) expression.
bitwise logical operator. The LOR, LAND, or XOR operator, which performs a bit-by-bit
operation on INT expressions.
blocked global data. Data you declare within BLOCK declarations. See “BLOCK
declaration.”
BLOCK declaration. A means by which you can group global data declarations into a
relocatable data block that is either shareable with all compilation units in a program
or private to the current compilation unit.
Boolean operator. The NOT, OR, or AND operator, which sets the state of a single value
or the relationship between two values.
breakpoint. A location in a program at which execution is suspended so that you can
examine and modify the program state. Breakpoints are set by Inspect or Debug
commands.
built-in function. See “standard function.”
byte. An 8-bit storage unit; the smallest addressable unit of memory.
CALL statement. A statement that invokes a procedure or a subprocedure.
CALLABLE procedure. A procedure you declare using the CALLABLE keyword; a
procedure that can call a PRIV procedure. (A PRIV procedure can execute privileged
instructions.)
CASE expression. An expression that selects an expression based on a selector value.
CASE statement. A statement that selects a statement based on a selector value.
central processing unit. See “CPU.”
character string constant. A string of one or more ASCII characters that you enclose
within quotation mark delimiters. Also referred to as a character string.
CISC. Complex instruction set computing. A processor architecture based on a large
instruction set, characterized by numerous addressing modes, multicycle machine
instructions, and many special-purpose instructions. Contrast with “RISC.”
CLUDECS. A file, provided by the CRE, that contains external declarations for CLULIB
functions. See also “CLULIB.”
CLULIB. A library file, provided by the CRE, that contains Saved Messages Utility
(SMU) functions for manipulating saved startup, ASSIGN, and PARAM messages.
code segment. A segment that contains program instructions to be executed, plus
related information. Applications can read code segments but cannot write to them.