IBM System/360 Operating Guide

1. Manual alteration of an instruction address or
a ROS address (F, G, H, and J).
2. Manual entry of the load-unit address (G, H,
and J).
3. Manual entry of a byte of information into main
storage or into a data-flow register (H and J).
~ The functions of these four switches are
described in detail in other sections of this manual.
Switch F is also used for 1400 compatibility opera-
tions (see IBM System/360 Model 1400 Compatibility
Feature, Form A24-3255). Switches F and G have
particular significance for 1620 compatibility opera-
tions (see IBM System/360 Model 30, 1620 Compati-
bility Feature, Form A24-3365).
CONSOLE CONTROLS
The manual controls on the 2030 console permit the
operator to initiate system operation in any of
seyeral modes, and to perform display and store
operations.
Note: Storage Protection is not effective during
main-storage alteration or display operations
initiated from the console. Care must be exercised
to ensure that useful data is not unintentionally
altered.
Data and Address Entry Swit ches
Eight rotary switches are provided for manually
entering data or addresses into the system. Each
of these sixteen-position switches provides one
hexadecimal digit (four bits plus parity). Switches
A, B, C, and D are used to enter an address for
manual operations involving main or auxiliary stor-
age, or to set up a compare address. These four
switches are connected to the main-storage address
register and to the compare (match) circuits.
Switches F, G, H, and J are used to set up an
instruction address, a ROS address, a load-unit
address, or enter manual data into the system.
These four switches are connected to the data-flow
system through the A- and B-registers.
These switches are normally used as follows:
Switch
A,B,C,D
A,B,C,D
F,G,H,J
G,H,J
H,J
Function
A stop or restart address to be
matched against the contents of
the Main Storage Data Register
(MSDR) or the ROS address regis-
ter (WX),
A
main-storage address for manual
store or display operations.
An instruction-Start address or a
ROS-Start address for a manual
operation.
The load-unit address (I/O device
and channel address from which
the program is to be loaded),
A data byte to be loaded into main
or auxiliary storage, or into a
data-flow register.
The specific functions provided by these eight
switches are detailed in various sections of this
publication.
Switches F and G also have functions unique to
the 1400 and 1620 compatibility features.
Display-Storage Selection Dial
This control can be used to display information
from (or store into certain) system registers that
do not have full-time indicators on the console. In
addition, proviSion is made to display from or store
into any main-storage or auxiliary-storage location.
The dual-concentric rotary switch labeled E is used
to access the registers and system control points
shown on the dial (Figure 3).
Use of the Storage-Display Selector switch is
described in the Display and Store Operations
section.
~s MS
\ I
~
~
0
"'TI
-i
v"
~
0 ~
/I
5 ')
Figure 3. Display-Storage Selection Switch
9

IBM System/360 Specifications

General

Brand	IBM
Model	System/360
Category	Desktop
Language	English