The evolution of storage: yesterday, today,
& tomorrow
by Alan Zisman
(c) 1996. First
published in Computer Player, May 1996
Where does your data go when you flip off the power
switch?
Unless you?ve saved your file, the answer, of course,
is to that big
bit-bucket in the sky?in other words, it?s gone unless you?ve stored
it.
Your computer needs storage... not just to save your data files, but to
store your applications, and even the operating system. Without being
able
to read and write files, your computer would be a mere shadow of
itself.
Not useless, mind you?we use a lot more computers than
we?re aware of,
mostly in the form of embedded processors. CPUs with a relatively small
amount of instructions permanently burned into ROM chips, in our cars,
cameras, microwaves, and VCRs. But without storage, these computers are
limited to a single purpose... not really computers as we know them.
Yesterday...
For the first personal computers, storage was slow and
unreliable...
paper tapes on the pioneering Altair; cassette tapes on later Commodore
VIC-20s, for example. Even the first IBM Personal Computer had a port
for
a cassette player. But a big breakthrough came when Apple co-founder
Steve
Wozniak designed a floppy-drive interface for the Apple II, permitting
it use relatively fast cheap and reliable disks. Even though floppy
disks
were an extra-cost add-on for those early Apples and IBMs, they were
clearly
the way to go.
Floppy diskettes shrank in size and grew in capacity,
from the 160kb
5¼? disks of those first IBM PCs to the 360kb
double-sided,
double-diskette disks of IBM?s XT to the 1.2 meg 5¼? AT
diskettes.
Smaller, more durable 3½? diskettes were first popularized as
400kb
single-sided models on 1984s ground-breaking Apple Macintosh, growing
in
capacity to 800kb and then 1.44 meg models, now standard on both Macs
and
PCs. (And yes, these hard-shelled diskettes are still floppy disks...
break
one open and see).
IBM tried to establish a higher-density standard, 2.88
meg diskettes,
in the late 80s, but these have failed to become popular?drives and
disks
are rare and expensive; other than that, floppy disk technology has
pretty
much remained stagnant, with the older 5¼? being left off
most new computers to make room for CD-ROM players.
Even though a 1.44 meg diskette holds almost ten times
as much as the
initial generation of floppies, even users of early personal computers
ran into problems... You quickly ended up with a collection of
floppies,
and had to shuffle between them. And applications soon required
multiple
diskettes?you might have to swap disks to spell check your word
processor
file.
Mainframe and minicomputer users had been making use
of a technology
that used rigid platters?hence the name hard disks. Some models were
removable,
but most stayed in a permanent stack, in a unit with multiple
platters?IBM
(which often prefers its own names for things) called these fixed
disks.
But these were too big and too expensive for personal computer users.
Even
when they were scaled down to 5¼? size to fit in a PC, a hard
drive
with a then massive-seeming 5 megabytes of storage might cost $2000 or
so.
A breakthrough occurred in 1983, when IBM released its
XT model?basically
a barely upgraded original PC, but with a 10 meg hard drive included. A
year later, the AT doubled that, with a 20 meg drive...giving owners of
that $5,000 machine visions of unlimited storage. Room for all the key
business programs of the mid-80s, 1-2-3, WordStar, and dBase, along
with
your data.
Even then, there were alternatives. Some users
preferred removable storage,
and companies like Iomega and Syquest provided it. Prime Minister John
Turner, in his Vancouver office, for instance, used a PC together with
a unit offering twin 10-meg Iomega Bernoulli boxes; a total of 20 megs
of removable storage.
Today...
Hard drives have shrunk in size and cost, while
growing tremendously
in capacity and reliability.
In 1988, I purchased a 40 meg hard disk on sale for
$400... today, a
gigabyte (a billion bytes?25 times as large) drive is about ¼
the
size, and little more than half the price. And by the end of the year,
expect that gigabyte drives will be the standard capacity offered on
computers
aimed for home and business use.
Inside, these units still look like miniatures of a
1970s-style hard
drive?a stack of metal platters, spinning at high speed. But
breakthroughs
in the technology of packing magnetic information onto the disks has
made
it possible to manufacture small, high-capacity drives for the same
cost
as the much less capable units of even two years ago.
At the same time, newer PCs include support for larger
drives?so-called
Logical Block Addressing (LBA) built in, making it easy to add drives
larger
than 512 meg... formerly a limitation that could only be overcome with
special hardware or software.
Drives are available in two basic flavours. EIDE is
the common standard
for PCs... now that the 512 meg limitation has been bypassed,
permitting
cheap, high capacity drives. SCSI, first made common on Apple Macintosh
models, also permits high capacity drives, and can provide performance
and features beyond EIDE. SCSI remains non-standard on PCs, however,
and
as a result, SCSI drives cost more than their EIDE equivalents (and
users
also typically need to purchase a $200-300 adapter).
Tomorrow?
It seems clear that hard drive capacities are going to
continue to increase,
at least for a while, with gigabyte capacities becoming standard, and
multi-gig
units increasingly common and affordable.
The biggest changes, however, seem to be happening
with removable storage.
Since the adoption of the 1.44 meg floppy almost a decade ago, this
area
had been pretty stagnant; users needing higher capacities (typically
graphics
professionals, using Macs) tended to standardize on the 40meg Syquest
cartridges,
which, requiring SCSI, were rare among PC users.
The past year has changed all that. Iomega?s ZIP
drive, a $300 (CDN)
unit using 100 meg disks costing about $20 each has threatened to
become
a new standard. It?s available in SCSI models for both Mac and PC, and
in a parallel-port PC unit, which while slower than the SCSI version
can
be easily moved from computer to computer.
(SCSI users may prefer Syquest?s faster and higher
capacity EZ-135...
unfortunately, the Syquest and Iomega models can?t share disks).
But 100-135 megs may not be enough, and both Iomega
and Syquest are
among the companies offering even higher capacity removable storage at
relatively affordable prices. Again, Iomega appears to be first off the
mark?their Jaz drive is just starting to become available, offering
both
internal and external (SCSI only) drives using massive 1 gig
cartridges.
At about $600 (US) for the drive, and $100 (US) per cartridge, these
are
initially pricier than hard drives, but become increasingly economical
as more cartridges are purchased. And performance promises to be within
the range of hard drive performance.
Even tape is making a bit of a comeback. Slow and
linear, it isn?t going
to replace hard drives or diskettes for storing often-used programs or
data, but it has built a niche as a low-cost media for back-up
purposes.
Recently, low cost drives have become available from a number of
companies,
using 800 meg Travan tapes. At $40 per tape, these are quickly
replacing
the older but more expensive drives running QIC-80 style tapes. (The
Travan
units can also use the older QIC-80 tapes). And parallel-port tape
drives,
such as MicroSolutions? BackPack or Iomega?s Ditto can be easily used
to
backup multiple PCs? data, while costing only around $250 (CDN). Note
that
as with the parallel port ZIP drive, parallel port tape drive
performance
can be increased dramatically using enhanced or ECP parallel ports.
Again, SCSI provides the high end alternative.
SCSI-based DAT tape drives
can archive a couple of gigabytes of data onto a standard digital audio
cassette tape... about $30 per cassette, but the drives themselves
still
cost around $2,000.
For a time, it seemed as if recordable-CD-ROM (CD-R)
would become a
new standard medium, but I?m pessimistic, at least in the short term.
Writable CD drives remain expensive, hovering around
$1,000 or more,
and more important, difficult to use. Users need a fast, big hard
drive,
with a CD?s worth of unfragmented free space (about 650 megs). Even
then,
recording remains hit and miss?users often find they?ve ruined a $20
use-once
blank disk. And the CD standard is about to change?from the 650 meg
current
disks, to the 3.7 gig (higher capacities later) DVD (also known as
SD-ROM).
Expect high-priced DVD units near the end of the year, with a couple of
years before this becomes a widespread standard.
For the near future, at a minimum, look for gigabyte
or larger EIDE
hard drives in entry-level machines. Hopefully, enhanced (or ECP)
parallel
ports will become standard, as more and more devices are sold making
good
use of the added performance and convenience of these ports. Built-in
SCSI
may become more common on mid-level machines, making it possible for
buyers
of these units to make use of devices such as the Jaz drive; higher end
machines may even start offering internal Jaz drives for fast,
high-capacity
removable storage.