| IRQ | Interrupt Request Channel. A path through which a device can get the |
| immediate attention of the computer’s CPU. The PCI bus assigns an IRQ |
| path for each SCSI host adapter. |
| ISA | Industry Standard Architecture. A type of computer bus used in most |
| PCs. It allows devices to send and receive data up to 16 bits at a time. |
| Kbyte | Kilobyte. A measure of computer storage equal to 1024 bytes. |
| Local Bus | A way to connect peripherals directly to computer memory. It bypasses |
| the slower ISA and EISA buses. PCI is a local bus standard. |
| Logical Unit | A subdivision, either logical or physical, of a SCSI device (actually the |
| place for the device on the SCSI bus). Most devices have only one logical |
| unit, but up to eight are allowed for each of the eight possible devices on |
| a SCSI bus. |
| LUN | Logical Unit Number. An identifier, zero to seven, for a logical unit. |
| Mainboard | A large circuit board that holds RAM, ROM, the microprocessor, custom |
| integrated circuits, and other components that make a computer work. It |
| also has expansion slots for host adapters and other expansion boards. |
| Main Memory | The part of a computer’s memory which is directly accessible by the CPU |
| (usually synonymous with RAM). |
| Mbyte | Megabyte. A measure of computer storage equal to 1024 kilobytes. |
| Motherboard | See Mainboard. In some countries, the term Motherboard is not |
| appropriate. |
| Multitasking | The executing of more than one command at the same time. This allows |
| programs to operate in parallel. |
| Multithreading | The simultaneous accessing of data by more than one SCSI device. This |
| increases the data throughput. |
| NVRAM | NonVolatile Random Access Memory. Actually an EEPROM |
| (Electronically Erasable Read Only Memory chip) used to store |
| configuration information. See EEPROM. |
A program that organizes the internal activities of the computer and its peripheral devices. An operating system performs basic tasks such as moving data to and from devices, and managing information in memory. It also provides the user interface.
Glossary of Terms and Abbreviations |