8 Dec
2014
8 Dec
'14
6:27 p.m.
On Sunday, December 07, 2014 5:10 PM Fred Cisin
[mailto:cisin at xenosoft.com] wrote
On Sun, 7 Dec 2014, Chuck Guzis wrote:
> Oh, it started before the Mac. Consider, for
example, the Technical
> Reference for the IBM PC (first edition). Clear
as day, it talks
>about memory expansion options of
"256K". Even so, consider older
>CP/M machines--many of them used the memory
available in the signon as
"XXK"
I remember some booth staff at West Coast Computer
Faire (1979?) trying to
tell me that their computer with 65.5K of RAM was better
than the
competition's 64K.
It was certainly well established by the time of
TRS80/Apple][/Pet.
(4K,16K,48K, . . . )
> It probably goes back well into the 60s talking
about so many "kilowords"
of memory or mass storage.
Thanks for the comments but I still content the mess really started with
Apple's Macintosh OS which REPORTED MEMORY AND DISK CAPACITY USING K in a
binary sense without any qualification. There is no doubt that K and M were
used in a binary sense before Macintosh, but AFAIK not by any OS for disk
capacity.
MSDOS and PCDOS AFAIK did not use any prefixes - the utilities just reported
the values in a string of decimal digits without commas. Interesting but
not surprising that CPM used binary K on memory but I doubt it reported on
disk capacity using any prefixes, but I could be wrong. Don't know about
TRS80 and PET but I doubt the OSes used prefixes of any sort.
The real mess started when an OS reported a disk drive advertised in
conventional MB using binary MB e.g. an ST225 advertised by Seagate as
having 21.4 million bytes but reported by an OS as having a 20910 KB
capacity (41,820 512 byte sectors per Seagate spec = 21.411.840 bytes = 21.4
MB). Where is the missing 490 KB? Macintosh OS System 1 is the first OS
that I know about.
Tom