Re: Apple II still ahead of the curve!

["William Garber" <willy46pa@garberstreet.com>]

"Scott Alfter" <scott@alfter.DIESPAMMERSDIE.us> wrote in message news:45359e04$0$5903$9a6e19ea@news.newshosting.com...
: In article <bOadnXMYQfSatKnYnZ2dnUVZ_o2dnZ2d@comcast.com>,
: Michael J. Mahon <mjmahon@aol.com> wrote:
: >William Garber wrote:
: >> "mdj" <mdj.mdj@gmail.com> wrote in message
: >1160991353.814512.121080@m7g2000cwm.googlegroups.com">news:1160991353.814512.121080@m7g2000cwm.googlegroups.com...
: >> : PZ wrote:
: >> : > I don't believe it.  The Focus card is 100% smartport compatible and
: >> : > allows something like 32+ partitions under GSOS, ProDOS or otherwise,
: >> : > with no onboard RAM that I know of.
: >> :
: >> : Are the partitions perchance fixed size, not including the last
: >> : partition ?
: >>
: >> No, as with the Microdrive, the partition table of
: >> the Focus is stored on the drive itself. It is read
: >> with each access of the drive.
: >
: >Ouch!  So every access involves two seeks and two reads??
:
: That sounded somewhat less than optimal to me at first.
: It no doubt is, but the performance hit shouldn't be as
: bad as it sounds at first.  Nearly all hard drives have
: some amount of cache on them.  As long as the partition
: table is in the cache, reading it from the drive isn't
: going to cause a seek.

At the risk of upsetting someone, looking at the Microdrive,
it has a 2K cache ram onboard, but I think that is for the
purpose of caching the data as it passes from buss to buss,
being the partition map is $80 bytes for master, Drive 0,
and another $80 for slave, Drive 1. Each drive can have but
8 Partitions, I believe.

William Garber
Email Address - willy46pa@garberstreet.com
Web address - http://www.garberstreet.com