Specifications

Glossary GL–9
hot swap A method of device replacement that allows normal I/O activity on a device’s
bus to remain active during device removal and insertion. The device being
removed or inserted is the only device that cannot perform operations during
this process.
See also cold swap and warm swap.
HSUTIL Format and device code load utility.
IBR Initial Boot Record.
ILF Illegal function.
INIT Initialize input and output.
initiator A SCSI device that requests an I/O process to be performed by another SCSI
device, namely, the SCSI target. The controller is the initiator on the device
bus. The host is the initiator on the host bus.
instance code A four-byte value displayed in most text error messages and issued by the
controller when a subsystem error occurs. The instance code indicates when
during software processing the error was detected.
interface A set of protocols used between components, such as cables, connectors, and
signal levels.
I/O Refers to input and output functions.
I/O driver The set of code in the kernel that handles the physical I/O to a device. This is
implemented as a fork process. Same as driver.
I/O interface See interface.
I/O module A 16-bit SBB shelf device that integrates the SBB shelf with either an 8-bit
single ended, 16-bit single-ended, or 16-bit differential SCSI bus.
I/O operation The process of requesting a transfer of data from a peripheral device to
memory (or visa versa), the actual transfer of the data, and the processing and
overlaying activity to make both of those happen.
IPI Intelligent Peripheral Interface. An ANSI standard for controlling peripheral
devices by a host computer.
IPI-3 Disk Intelligent Peripheral Interface Level 3 for Disk
IPI-3 Tape Intelligent Peripheral Interface Level 3 for Tape