bootstrap loader
<operating system> A short {program} loaded from {non-volatile
storage} and used to {bootstrap} a computer.
On early computers great efforts were expended on making the
bootstrap loader short, in order to make it easy to {toggle}
in via the {front panel} switches. It was just clever enough
to read in a slightly more complex {program} (usually from
{punched cards} or {paper tape}), to which it handed control.
This {program} in turn read the {application} or {operating
system} from a {magnetic tape} drive or {disk drive}. Thus,
in successive steps, the {computer} "pulled itself up by its
bootstraps" to a useful operating state.
Nowadays the bootstrap loader is usually found in {ROM} or
{EPROM}, and reads the first stage in from a fixed location on
the {disk}, called the "{boot block}". When this {program}
gains control, it is powerful enough to load the actual {OS}
and hand control over to it. A {diskless workstation} can use
{bootp} to load its OS from the network.
(2005-04-12)