Honeywell 200 Series User Manual

SECTION II. OPERATOR'S CONTROL PANEL
CONTROL ENTER
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The CONTROL ENTER button is effective only when the system is in the STOP mode. When
it is depressed, the octal configuration displayed in the ADDRESS indicators is written into the
control memory register designated by the CONTROL indicators. The previous contents of the
control memory register are destroyed, and the character in main memory which is stored at
the new address is displayed in the CONTENTS indicators. If incorrect parity is stored with the
new character, or if the addressed location does not exist, the PARITY indicator is illuminated.
(Refer to page 2-11 for a complete description of the PARITY indicator.) It should be noted that
pressing the CONTENTS ENTER button does not cause an internal interrupt demand to be set.
STOP Button
•
o
The STOP button is illuminated when the system is in the STOP mode. It is not illuminated
when in the RUN mode. In the STOP mode, the system executes no program instructions, and
peripheral devices may be actuated only by manual "stepping." In the RUN mode, the system
operates automatically. Depressing this push button enables the central processor to be de-
energized when the RESET DC OFF button is depressed. If an interrupt signal is received
while the system is in the STOP mode, the EXTERNAL indicator (see page 2-12) becomes il-
luminated when the RUN mode is subsequently entered.
In a normal stop, the instruction under extraction or execution at the time of the stop is
fully executed and is the last one performed, regardless of interrupt processing. The STOP
mode is not entered nor the STOP button illuminated, however, until all peripheral operations
that are in progress have been completed.
The STOP mode can be entered in one of six ways:
1. When a program Halt (H) instruction (with or without branch) is executed
(normal stop);
2. When the STOP button is depressed (normal stop);
3. When a parity failure occurs. A parity failure is not a normal stop,
and the instruction under execution is stopped at the end of the current
memory cycle; however, all peripheral operations are allowed to be
completed. While the peripheral operations are completing, neither the
STOP indicator nor the RUN indicator is illuminated;
4. When the SYSTEM CLEAR button is depressed after the STOP button
has been depressed. This is not a normal stop (see below, "SYSTEM
CLEAR Button");
5. When the INITIALIZE button is depressed after the STOP button has been
depressed. This is not a normal stop (see below, "INITIALIZE Button"); and
2-5

Honeywell 200 Series Specifications

General

Brand	Honeywell
Model	200 Series
Category	Desktop
Language	English