PC Cards... the little cards that could
by Alan Zisman
(c) 1996. First
published in Computer Player, January 1996
What?s 8.64 mm by 56 mm and lets you do almost
anything you want? If
you answered ?an American Express Card? you?re probably watching too
TV... but if you answered a PC Card in a portable computer, you?re
on the money.
Portable computers are great-- but up until recently,
they had a big
disadvantage compared to their desk-bound counterparts. Desktop PCs are
expandable, you see. You want to add a sound card? A network
A modem? A CD-ROM? No problem. At worst, you?ll have to open the case,
and pop an interface card into an unused slot. (Well, actually, at
you?ve got a whole mess of incompatibilities involving techie topics
IRQ and DMA settings, but we?ll leave those for some other article).
Portable, you see, have no slots. And that has meant
limited and no expandability. If you couldn?t plug it into the parallel
or serial ports in the back, forget it. Maybe your portable has a long
skinny plug for a docking station or a port replicator, but does anyone
actually use one of those? And even if you did-- what is good is that
your portable goes out of the office... and that?s the whole idea of
Take modems, for example. A modem can be a very useful
tool to anyone
traveling with a portable computer-- even just as far as from the
to home and back. Portable manufacturers used to be very happy to sell
built-in modems for their models-- over-priced 2400 bps modems, sold to
a captive market, that is-- with each computer model needing a
model modem. But what were the alternatives? Carry a bulky external
Buy an equally overpriced mini-modem? Lacking any sort of standards for
portable computers, users often simply did without.
PCMCIA TO THE RESCUE
Starting in 1989, the Personal Computer Memory Card
tried to create a standard, and also, at the same time, a
acronym. At first, the PCMCIA cards were limited to memory cards (as
association?s name suggests), and at first, they represented a standard
that wasn?t, as early models were plagued with incompatibilities.
the standards have been tightened, and now extend to a wide range of
and to the software needed to allow it to run.
Renamed simply PC cards, there are now three standard
sizes. Type I
cards are the thinnest-- up to 3.3 mm thick. Most of these remain
cards. Type II sockets can hold two Type I cards or a single 5.5 mm
II card. These are the most common-- modems, Ethernet network adapters,
SCSI cards, even sound cards can be found in this format. 10.5 mm Type
III cards are mostly hard drives. A Type III socket can hold a Type II
and a Type I card, or up to three Type I cards. Finally, Toshiba has
an even thicker Type IV socket-- but this is not yet a widely-supported
Software drivers-- so-called Card and Socket Services
to be loaded, to let your computer know about the existence of your PC
cards. Under DOS and Windows 3.x, these drivers require ram-- 60kb or
for each card loaded. While these drivers can be loaded high, this can
cause problems running some programs-- especially if you need to load
ADVANCED OPERATING SYSTEMS TO THE RESCUE!
OS/2 Warp and Windows 95 don?t have these problems.
Both operating systems
have support for PC cards built in. Windows 95, for example, does away
with needing drivers for these cards in CONFIG.SYS or AUTOEXEC.BAT-- if
installation notices a PC card slot, an icon will appear in Control
It?s a simple matter to turn on support for PC cards.
And once support is turned on, Win 95 supports hot
or removing cards while the computer is up and running. Add a card for
the first time, and the computer will take a few seconds to identify
If it?s new, it will inform you that it is loading drivers (you may be
asked to insert one of your Win 95 floppies)... then a PC card icon
up on the TaskBar, and you?re in business. Plug and Play like it?s
to be. And sheer magic if you?ve wrestled with installing cards in
desktop PCs, under DOS or Windows.
While Warp doesn?t call it Plug and Play, it also has
built-in card services.
You should be aware, however, that while using Warp or
Win 95 really
makes the use of PC Cards much more convenient, either really requires
at least 8 megs of ram to run well-- and most portables are still being
sold with only 4 megs. And just as they can?t use standard expansion
most portables require special, and pricier ram... I wouldn?t recommend
four megs on any new computer purchase-- portable or desktop.
WHAT CAN FIT ON A CARD?
Considering the small size of a PC card (literally
about the same size
as that American Express card, but a bit thicker), it?s amazing what
be squeezed into the thin metal case. I don?t recommend cutting one
to peek inside, but if you did, you might see ram chips, digital signal
processors, and other standard chips-- all neatly soldered onto two
of a thin board. In fact, everything you need for a standard adapter
just forced into a smaller case.
This miniaturization inevitably results in somewhat
higher prices than
for their larger equivalents, but as the portable market expands (it?s
currently 1/4 of the entire market for personal computers, and rising),
the prices of PC Cards is also dropping. A 14.4 kbs PC Card modem may
$200-250, compared to about half that for a standard modem, while a
28.8 modem may cost $400-500 on a PC Card, compared to $250-400 for its
PC Card modems seem the most common of the mini
add-ons, with a range
of models at both the 14.4 kbs and 28.8 kbs speeds. All have fax
and all seem to offer fairly similar capabilities-- performing
identically to larger models with the same rated speeds. The biggest
lies in how to attach the phone jack. Some models, such as Megahertz?s
X-Jack models, sport an actual phone jack-- inset in the PC Card?s
shell. Press on the end, and the X-Jack pops out, ready to accept a
phone cord. This is a convenient arrangement, allowing users to use any
phone cord. It can?t be lost, but it can break off. Several other
prefer to include special phone cords, which plug into the end of the
Card... these may be more sturdy, but if you forget or lose the cord,
modem is unusable.
Modems aren?t the only use for these versatile cards--
that can be plugged into a standard ISA jack can be miniaturized onto a
PC Card. Currently, you can buy SCSI adapters from several
This allows you to connect a wide range of external SCSI devices, from
hard drives to scanners to tape backup to CD-ROM. Or maybe you?d prefer
a sound card. Ethernet networking cards come with your choice of
or 10-base-2 connectors. Hard drives, up to 170 megs have been squeezed
into a fat Type III card. There?s even a video capture board on a card.
Increasingly popular are multifunction cards. These
cards in one. Combining an Ethernet adapter and a modem into a single
is an example of this.
COMING RIGHT UP
PC Cards are handy. So handy, in fact, that they may
migrate from portables
to desktop computers. IBM?s PC 300 desktop models already include Card
slots, and several companies market adapters letting users add PC Cards
to any desktop computer. With this, you could use a single,
sized modem on all the machines that you work with.
Currently, the PC Card standard is a 16-bit, 6 MHz
adapter-- sort of
like a slow, ISA slot on a desktop PC. A new standard is evolving,
Called CardBus, it will allow 32-bit operation, at speeds ranging from
20 to 33 MHz. Sort of the local-bus standard for the next generation of
So we can soon expect increasingly fast and powerful
PC Cards, as well
as more and more devices crammed onto a single card-- look for the
modem, network adapter, SCSI card, combined with sound card featuring
input and speaker outputs. Wonder where all those plugs are going to
PC Cards have outgrown a somewhat awkward adolescence.
They now greatly
extent the usefulness of our portable computers, making it much more
for these tiny machines to almost entirely replace the big, lumbering
models. Expect to see them popping up wherever people take their
from the office to home, on the road, even on vacation.