User guide

Glossary

In glossary definitions, italics are used for items defined elsewhere in the glossary and bold is used for the items

shown in brackets after the main heading of the entry.

ASCII American Standard Code for Information Interchange. A 7-bit binary code (0's, 1's) used to represent

letters, numbers, and special characters such as $,!, and /. Supported by almost every computer and terminal

manufacturer.

Attribute Setting that controls access to a specific file. Often used to protect important files (such as the Registry

files) from accidental change or deletion. Set using the ATTRIB command in MS-DOS.

Backplane A printed circuit board incorporated in the Rorke Data chassis assembly to provide logic level signal,

and low voltage power distribution paths.

Bay The slot that a unit or media device fits into.

Byte A group of binary digits stored and operated upon as a unit. A byte may have a coded value equal to a

character in the ASCII code (letters, numbers), or have some other value meaningful to the computer. In user

documentation, the term usually refers to 8-bit units or characters.

1 kilobyte (K) is equal to 1,024 bytes or characters; 64K indicates 65,536 bytes or characters.

Cable Throughout this Galaxy 55 user guide this term is used in accordance with the preferred US context of: “an

insulated flexible electric wire used for the transmission of data signals between computer equipment.”

Note: Cable is UK preferred terminology for either a power cord or a data cable:

Character A representation, coded in binary digits, of a letter, number, or other symbol.

Characters Per Second A data transfer rate generally estimated from the bit rate and the character length. For

example, at 2400 bps, 8-bit characters with Start and Stop bits (for a total of ten bits per character) will be

transmitted at a rate of approximately 240 characters per second (cps).

Chassis a number of aluminum extruded sections which are bonded together to form a segmented assembly

containing a number of 'Bays', Each bay can accommodate a plug in module. Two of these assembled sections are

then secured together and between these a Backplane PCB is 'sandwiched' to form the chassis assembly.

Configure To set up a hardware device and its accompanying software.

Data Communications A type of communications in which computers and terminals are able to exchange data

over an electronic medium.

Disk (drive, carrier, module) A FC-AL disk drive mounted in an extruded aluminum carrier. You can have

up to twelve disk drive carrier modules in each Galaxy 55 enclosure.

Enclosure The chassis assembly which houses the plug-in modules that make up the Galaxy 55 storage

subsystem.

ESI/Ops module A plug-in module which can be fitted in the enclosure either front or rear facing. used to

monitor and control all elements of the Enclosure.

Hot plugging A device with the capability of being connected to a subsystem without interrupting the power

supplies to that subsystem.