The REALTIME command provides a way to execute a series of operations with precise timing.
The command's repertoire of allowable operations is designed to provide most of the building
blocks necessary to control the video display, read and write analog and digital data using
peripheral hardware capabilities, and manipulate data within the computer's memory.
The available operations also provide a fairly comprehensive programming environment that
includes direct access to all of CIGAL's data variables. Most importantly, REALTIME operations
have been optimized for rapid execution and the command itself arbitrates scheduling issues to
provide accurate and consistent execution timing.

The REALTIME command accepts the following arguments:

RT_FILE
Normally, RT_FILE is the name of a disk file containing the list of
operations and the times at which they are due to execute. REALTIME
reads and compiles this list into a series of internal sublists, each of
which contains a sequence of operations to be executed in chronological
order. The different sublists execute in parallel to provide multiple,
independently timed control streams. See help for RT_OPS[6] and
RT_FILE[6] for information about the individual operations and the
syntax of the RT program file.

If REALTIME is called with no arguments, a previously suspended RT
program is resumed (see P_PAUSE[6]). If the RT_FILE argument is 0, a
previously suspended RT program is terminated, releasing all allocated
memory. If there is no suspended RT program this command has no effect.

If the RT_FILE argument is a - (minus sign, eg. CIGAL's missing
argument placeholder), the REALTIME command reads the list of operations
from the standard input (keyboard if entered interactively or current
file if running from a macro). The list of operations ends when a '}'
command line is encountered, or when you enter a blank line if running
interactively; at that point REALTIME compiles the list and begins
execution of the operations.

RUNLOG
This is an array or matrix variable which REALTIME will fill with a log of
the operations it performed and the actual time at which those operations
were executed. Which operations generate log entries depends on the
operation flags specified in the RT_FILE, as well as the value of the
MODE argument (see below). Each entry in the RUNLOG consists of 8 bytes:
long exec_time ; actual time executed
byte opcode ; code for operation executed
byte eventflag ; identifies individual operation
integer exec_flag ; optional op-specific flags
If RUNLOG is omitted, REALTIME executes but does not record a log.

MODE
This is a flag specifying REALTIME execution options. 0 - execute RT program normally (default) 4 - execute RT program normally, except that after each operation has completed the amount of time the operation took is stored in the EXEC_FLAG field of the RUNLOG. (Note: elapsed time only includes the time it takes from the scheduled execution time until the operation completes and does not include any time spent setting up the operation before its scheduled start time. 10o - execute RT program and record elapsed times, but ignoring the scheduled execution times. Each operation begins as soon as the previous operation is completed. In this case the elapsed time recorded is the total execution time required for the operation.

For more information on the REALTIME processor see HELP on:
RT_PROCESSOR - an overview of CIGAL's REALTIME processor
RT_SYNTAX - a description of REALTIME's operator syntax
P_SUMMARY - a descriptive summary list of REALTIME operators
P_OPS - a summary list showing the syntax of REALTIME operators

For more detailed information on any particular REALTIME operator ask for HELP
for that operator (for example, "help p_repeat").