Dread High-bit Disease
n. A condition endemic to PRIME (a.k.a. PR1ME) minicomputers that results in all the characters having their high (0x80) bit ON rather than OFF. This of course makes transporting files to other systems much more difficult, not to mention talking to true 8-bit devices. It is reported that PRIME adopted the reversed-8-bit convention in order to save 25 cents per serial line per machine. This probably qualifies as one of the most cretinous design tradeoffs ever made.
See meta bit.
A few other machines (including the Atari 800) have exhibited similar brain damage.