B&R Industries Automation PC 620, User Manual

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Appendix A • Glossary
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CMOS
»CMOS« is a battery powered memory area where fundamental parameters of an IBM (or
compatible) personal computer are stored. Information such as the type of hard drive, size of the
working memory and the current date and time are required when booting the computer. As the
name suggests, the memory is based on CMOS technology standards.
COM
A device name used to access serial ports in MS-DOS. The first serial port can be accessed
under COM1, the second under COM2 etc. Typically, a modem, mouse or serial printer is
connected to a serial port.
COM1
Device name for the first serial port in a PC system. The input-output area for COM1 is usually
found at address 03F8H. Generally, the COM1 port is assigned IRQ 4. In many systems, an
RS232 serial mouse is connected to COM1.
COM2
Device name for the second serial port in a PC system. The input-output area for COM2 is
usually found at address 02F8H. Generally, the COM2 port is assigned IRQ 3. In many systems,
a modem is connected to COM2.
COM3
Device name for a serial port in a PC system. The input-output area for COM3 is usually found
at address 03E8H. Generally, the COM3 port is assigned IRQ 4. In many systems, COM3 is
used as an alternative for COM1 or COM2 if peripheral devices are already connected to COM1
and COM2.
CompactFlash®
CompactFlash memory cards [CF cards] are exchangeable nonvolatile mass memory systems
with very small dimensions [43 x 36 x 3.3 mm, approximately half the size of a credit card]. In
addition to the Flash memory chips, the controller is also accommodated on the cards. CF cards
provide complete PC Card-ATA functionality and compatibility. A 50-pin CF card can be simply
inserted in a passive 68-pin type II adapter card. It conforms to all electrical and mechanical PC
Card interface specifications. CF cards were launched by SanDisk back in 1994. Currently,
memory capacities reach up to 8 GB per unit. Since 1995, CompactFlash Association [CFA] has
been looking after standardization and the worldwide distribution of CF technology
CPU
An abbreviation for »Central Processing Unit« Interprets and executes commands. It is also
known as a "microprocessor" or "processor" for short. A processor is able to receive, decode and
execute commands, as well as transfer information to and from other resources via the computer
bus.