Glossary

B

Backup

Duplicate of a program, storage medium or database. Created to backup or to protect irreplaceable data of working copies as a precaution against corruption or destruction. Some applications automatically create backup copies, while managing both the current version as well as the previous version that is stored on the hard disk drive.

Base Memory

The base memory is a part of the main memory. It is 640 Kbytes for all programming devices. The size is entered in the SETUP menu under the entry “System Memory” and is not changed even if the memory is extended.

Battery

In personal computers, batteries are used as an auxiliary source of power when the main power is shut off, as a power source for laptop and notebook computers (rechargeable batteries, such as nickel cadmium, nickel metal hydride, and lithium ion, are used), and as a method to keep the internal clock and the circuitry responsible for the part of RAM that stores important system information always powered up. Strictly speaking, only batteries that are not rechargeable are classified as batteries.

BIOS

Acronym for Basic Input/Output System. On PC-compatible computers, the set of essential software routines that tests hardware at startup, starts the operating system, and supports the transfer of data among hardware devices.

Boot Diskette

Boot disk that contains a boot sector and an initial loader for the operating system.

Boot

Start or restart of the PG. During the boot sequence the operating system is transferred from the system drive into the main memory.

Booting

Loading operation which transfers the operating system to the main memory.

Bps

The speed (in bits per second) with which information is transmitted over a data link.

SIMATIC Box PC 620 Manual

Glossary-3

A5E00131465-01

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Siemens 620 appendix Bios