On Sun, Mar 30, 2014 at 7:54 PM, Rich Freeman wrote: > On Sun, Mar 30, 2014 at 7:44 PM, Douglas James Dunn > wrote: > > The system you are most familiar with really depends on what Operating > > System you use. if you don't use computers you probably were exposed to > > either the SI units or imperial base 10 units. > > SI units ARE in base 10. Most imperial units aren't in base 10, and > the SI prefixes aren't generally used with imperial units. You don't > usually report height in centiyards, etc. > > There seems to be some kind of misconception that this has something > to do with imperial vs metric units. > > Bits and bytes are such a modern concept that they were pseudo-metric > from the start, but programmers tended to use the SI prefixes in > non-SI ways - defining a kilobyte as 1024 bytes. "Kilo" is an SI > prefix, but the SI defines it as 1000, not 1024. > > The 1024-byte kilobyte was never metric or SI or imperial. Fairly > recently JEDEC codified the 1024-byte kilobyte, but also endorsed the > 1024-byte kibibyte, and the usage obviously predates that standard. > Before then, programmers never really had a "standard" for the > kilobyte. Since programmers don't tend to do a lot of compound units, > getting their terms endorsed by a standards body was probably not much > of a priority. If they had gone to the SI/ISO (or whatever was around > in the 60s) they'd almost certainly have been shot down on having a > 1024-byte kilobyte. > > Rich > > I called it imperial base 10, in the fact that you count 1-9 before hitting 10 then 10-19 before hitting 20, rather than base 2, or whatever base you apply, not the fact that the units themselves are, and i realize that SI are in base 10 also.