Adaptec AHA-2742T User Manual - Page 114

Glossary MByte Megabyte. A measure of computer storage. One MByte equals 1,048,576 bytes. (A byte is the amount of storage needed to hold one character.) Micro Channel A 32-bit computer bus standard introduced by IBM with the PS/2 series of PCs. Micro Channel is an extension of the 16-bit ISA standard, allowing expansion devices to move data 32 bits at a time on the PC bus (also called Micro Channel architecture). Multi-tasking Operation The execution of commands in such a way that more than one command is in progress at the same time. Multi-tasking allows a computer system to take advantage of overlapping activities by using resources that are temporarily not required for other operations. More than one program or more than one portion of a program may be operating in parallel. Multi-threaded I/O A method by which data is accessed simultaneously from multiple SCSI devices to increase a system's data transfer rate. For example, if the system needs data from two disk devices it requests data from the first device, which temporarily disconnects from the SCSI bus while it is seeking the data. During this delay the system requests data from the second device, and while that device disconnects from the bus to seek the data, the first device starts sending the requested data over the bus, etc. The AHA2740 Series and all other Adaptec host adapters fully support multi-threaded I/O. P PC-AT A family of small computers sold by IBM, also called the Personal Computer/AT family of computers. The name is trademarked by IBM. PIO See Programmed Input/Output. Adaptec AHA-2740 Series User's Manual Stock Number: 510381-00 / Rev. C (Page G-9) Print Spec Number: 491709-00 Rev C Current Date: 9/1/93 ECN Date: 9/14/93 Glossary-9