User`s guide

ECC

Error Correction Code. Code that carries out automatic error correction by

performing an exclusive "or" operation on the transferred data and applying a

correction mask.

Factory Installed Software (FIS)

Operating system software loaded into a system disk during manufacture. On

site, the FIS is bootstraped in the system, prompting a predeﬁned menu of

questions on the ﬁnal conﬁguration.

FEPROM

Flash Erasable Programmable Read-Only Memory (FEPROM). FEPROMs use

electrical (bulk) erasure rather than ultraviolet erasure.

FIFO

First-in/ﬁrst-out. A method used for processing or recovering data in which the

oldest item is processed or recovered ﬁrst.

Firmware

Functionally it consists of diagnostics, bootstraps, console, and halt entry/exit

code.

FPU

Floating-point unit. A unit that handles the automatic positioning of the

decimal point during arithmetic operations.

FRU

Field replaceable unit.

GPR

General Purpose Registers. On the KA52/53, they are the sixteen standard

VAX longword registers R0 through R15. The last four registers, R12 through

R15, are also known by their unique mnemonics: AP (Argument Pointer), FP

(Frame Pointer), SP (Stack Pointer), and PC (Program Counter), respectively.

Initialization

The sequence of steps that prepare the system to start. Initialization occurs

after a system has been powered up.

IPL

Interrupt Priority Level ranges from 0 to 31 (0 to 1F hex).

Glossary–3