k=1000 or k=1024

[Joyce & Cordell Woods <jfwoods -at- MAROON -dot- TC -dot- UMN -dot- EDU>]

In technical documentation it is important to be precise.  The following
real-life example illustrates the cost of not being explicit.  This happened in
the 70's, when some large mainframe computers were still using magnetic core
memory.

In this particular case, the computer memory came in units of 32768 (32K) words
of 60 bits each.  The minimum configuration was 65K. (The computer manufacturer
used K to mean 1000.)

This did not present any problems for memory sizes of 32,768 (32K) or smaller.
However, the next multiples of 32K are 65,536, 98,304, and 131,072.  The
technical literature for the computers described memorys of 65K, 98K and 131K
words.

This went on for many years until one customer ordered a computer with 131K
specified in the contract and then demanded 131*1024 or 134144 words of memory.
After lots of yelling and moaning, the computer manufacturer gave the customer
and additional 65K of memory at a cost of several $100K!  (163K was not a
supported configuration.)  If the cost surprises you, remember each bit of core
memory and to be wired by hand.

Immediately, all technical literature was changed to NOT use the K units.  Each
memory size was specified exactly to the word.

The lesson is that if you do use k or K in documents relating to computers,
state in the document what it means, 1000 or 1024.  The same of m and M.

Cordell

-----------------------
Joyce F. Woods & J.Cordell Woods / Consultants
Cactus Software & Communications, Inc.
3151 Main Street NE; Blaine MN 55449-6112
voice 612/757-6916 fax 612/757-4515 email jfwoods -at- maroon -dot- tc -dot- umn -dot- edu