Bibi-binary express any number, it suffices to enumerate the (hexadecimal) digits that make it up. For example: the number written as "2000" in base ten, which translates to "7D0" in conventionally-written hexadecimal, would in Bibi-binary be spoken aloud as "BIDAHO". Contrary to the numeric conventions used in modern computers, the bibi-binary system represents negative numbers using one's complement, rather than two's complement. Thus: and their sum is written as "1 1111" (one of two representations of zero in this system; zero can also be written as "0 0000"). On modern machines, in classic binary notation, −7 would be written 1 1001,
Fat binary the data fork, in PEF format. Fat binaries were larger than programs supporting only the PowerPC or 68k, which led to the creation of a number of utilities that would strip out the unneeded version. In the era of small hard drives, when 80 MB hard drives were a common size, these utilities were sometimes useful, as program code was generally a large percentage of overall drive usage, and stripping the unneeded members of a fat binary would free up a significant amount of space on a hard drive. Fat binaries were a feature of NeXT's NeXTSTEP/OPENSTEP operating system, starting