Re: 5.25" Disk

[NO%lesh%SPAM%erjt%HERE@vuse.vanderbilt.edu (Tilghman Lesher)]

Edhel Iaur, Esq. (LOSETHECAPITALWORDSedhel@bigfoot.com) wrote:

: On 25 Apr 1997 18:02:17 -0400, dalloff@freenet.columbus.oh.us (Dave
: Althoff) wrote:

: >dwilson (dwilson@mail.nas.com) wrote:
: >:  How many k's of memory do 5.25" inch disks hold on average?
: >
: >On the Apple ][?  143k/side.

: I believe you assume incorrectly how much data is in a Kilobyte.

: DOS 3.3 Disk capacity:
: 256 bytes per sector * 16 sectors * 35 tracks = 143360 bytes per disk.
: 143360 bytes / 1024 bytes per Kilobybte = 140K per side.

Let me just post this to clear up a misconception.

It is commonly assumed that companies are "inflating" their
advertised disk size by assuming that there are 1000 bytes
per kilobyte.

In fact, it is the other way around.  Early in the computer
industry, the kilobyte WAS supposed to be 1000 bytes.  However,
due to either programmer laziness or the expense of RAM, the
estimation of 1024 bytes/kilobyte was used as "close enough".

As most of you know, to get K from number of bytes, you'd have
to divide by 1000.  However, an easy way to do this was to simply
do a bit shift (base 2) by 10 places.  This would divide by 1024,
which was just slightly off.  Close enough?  Perhaps, but it
became the standard way to calculate kilobytes.

This is why there is confusion today:  expensive RAM or lazy
programmers, take your pick.  Just don't blame the companies
for being lazy.  They're actually adhering to the REAL standard.

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