[probably came into prominence with the appearance of the
KL-10 (one model of the
PDP-10), none of whose connectors
matched anything else]. The tendency of manufacturers (or, by
extension, programmers or purveyors of anything) to come up
with new products that don't fit together with the old stuff,
thereby making you buy either all new stuff or expensive
interface devices. The KL-10 Massbus connector was actually
*patented* by
DEC, which reputedly refused to licence the
design and thus effectively locked third parties out of
competition for the lucrative Massbus peripherals market.
This policy is a source of never-ending frustration for the
diehards who maintain older PDP-10 or VAX systems. Their
CPUs work fine, but they are stuck with dying, obsolescent
disk and tape drives with low capacity and high power
requirements.
A closely related phenomenon, with a slightly different
intent, is the habit manufacturers have of inventing new screw
heads so that only Designated Persons, possessing the magic
screwdrivers, can remove covers and make repairs or install
options. Older Apple
Macintoshes took this one step
further, requiring not only a hex wrench but a specialised
case-cracking tool to open the box.
In these latter days of open-systems computing this term has
fallen somewhat into disuse, to be replaced by the observation
that "Standards are great! There are so *many* of them to