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Appendix A • Glossary
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287 Automation PC 820 User's Manual V 1.20
DRAM
An abbreviation for " D ynamic R andom A ccess M emory". Dynamic RAM consists of an
integrated semiconductor circuit that stores information based on the capacitor principle.
Capacitors lose their charge in a relatively short time. Therefore, dynamic RAM circuit boards
must contain a logic that allows continual recharging of RAM chips. Since the processor cannot
access dynamic RAM while it is being recharged, one or more waiting states can occur when
reading or writing data. Although it is slower, dynamic RAM is used more often than static RAM
since the simple design of the circuits means that it can store four times more data than static
RAM.
DSR
An abbreviation for " D ata S et R eady". A signal used in serial data transfer, which is sent by the
modem to the computer it is connected to, indicating its readiness for processing. DSR is a
hardware signal which is sent via line number 6 in compliance with the RS-232-C standard.
DTR
An abbreviation for " D ata T erminal R eady". A signal used in serial data transfer that is sent by
the computer to the modem it is connected to, indicating the computer's readiness to accept
incoming signals.
DVI
Abbreviation for " D igital V isual I nterface" An interface for the digital transfer of video data.
DVI-A
Analog only
DVI-D
Digital only
DVI-I
Integrated, i.e. analog and digital
EDID data
Abbreviation for " E xtended D isplay I dentification D ata". EDID data contains the characteristics
of monitors / TFT displays transferred as 128 KB data blocks to the graphics card via the Display
Data Channel (DDC). This EDID data can be used to set the graphics card to the monitor
properties.
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