Siemens Simatic 620 - Manual (Page 195)

Glossary
Glossary-5
SIMATIC Box PC 620 Manual
A5E00131465-01
Controller
Integrated hardware and software controllers that control the functions of certain
internal or peripheral devices (for example, the keyboard controller).
Cursor
Collective term for mouse pointer and text cursor.
Cursor Control
Keypad on the keyboard for controlling the cursor.
D
DC
Direct Current. Unidirectional electrical current.
DIMM
Dual Inline Memory Module. Memory RAM chips that are installed on the PCB,
similar to the more common SIMM (Single Inline Memory Module) chips. The
DIMM with its 64-bit data bus architecture has connections on both sides which are
connected to different circuits for processing different instructions. SIMMs,
however, have a 32-bit data bus architecture where all lines are connected to the
same circuit for processing the same instructions. DIMMs can be installed in the
computer as single chip, SIMMs, on the contrary, only in pairs.
Device Configuration
The configuration of a programming device contains information on hardware and
device options, such as memory configuration, drive types, monitor, network
address, etc. The data are stored in a configuration file and enable the operating
system to load the correct device drivers and configure the correct device
parameters.
If changes are made to the hardware configuration, the user can change entries in
the configuration file using the SETUP program.
Disk Drive
The disk drive (floppy disk drive) is used to store programs and data on diskette
(write access) or to load from diskette to the computer (read access).