HP Vectra Technical Reference Manual page 507

Real Mode:
One of the two modes that the 80286 can operate in. The Real mode provides
compatibility with the 8086 family of microprocessors.
Real-Time Clock: A clock circuit that maintains the correct time whether the system is on or
off. The real-time clock is powered by both the system power supply and battery. When the
system power is turned off, the clock continues to operate from the battery.
Return Status Code:
A
code returned by the EX-BIOS drivers that indicates the status of the
function requested.
ROM BIOS: The set of EX-BIOS and STD--BIOS drivers. These code modules are contained in
ROM modules on the Processor Extension Card.
ROM Module: Code and/or data stored in an EPROM or ROM.
RS-232C: An EIA standard for a serial data interface. Often used as a synonym for serial when
referring to system ports.
Scaling: The process of adjusting physical graphics coordinates to fit in a proportionately larger
or smaller logical space. The Input System scales the coordinates received from a tablet to fit into
its logical space.
Scancodes: Codes returned by the physical keyboard to indicate key makes and breaks.
Sector: A physical location on the disc where a block of data is stored. Disc surfaces are divided
~
into concentric rings called tracks. These rings are in turn divided into sectors.
Serial: To transmit data one bit at a time, serially. Used to indicate system ports that transmit
data in this fashion. See also RS-232C.
Single Step Interrupt: A processor interrupt generated after each instruction if the Single Step
flag is set. This interrupt is mapped by the 80286 to Interrupt vector 01 H.
Software Interrupts: Interrupts generated by the 80286 INT 'n' instruction where 'n' is the
interrupt number.
Sprite: A graphics cursor. The sprite is controlled by the Input System V_STRACK and
V_LHPMOUSE drivers.
Stagger: Disc stagger is the track to track offset between logical sectors. Stagger increases disc
performance during sequential read operations by adjusting for track to track access time. See
also INTERLEAVE.
STD-BIOS: The set of drivers that execute the industry standard BIOS functions.
System Software: See Operating System.
System Strings: Character strings stored in memory. Each EX-BIOS driver has a system string
associated with it. System strings are designed to provide a simple method for system software
to access them. In addition, their implementation provides a simple and effective method of
localization.
498 Glossary