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 much TV... but if you answered a PC Card in a portable computer, you?re right 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 connection? 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 worst, you?ve got a whole mess of incompatibilities involving techie topics like IRQ and DMA settings, but we?ll leave those for some other article).

Portable, you see, have no slots. And that has meant something between 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 when your portable goes out of the office... and that?s the whole idea of portables!

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 office 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 different model modem. But what were the alternatives? Carry a bulky external modem? Buy an equally overpriced mini-modem? Lacking any sort of standards for portable computers, users often simply did without.


Starting in 1989, the Personal Computer Memory Card International Association tried to create a standard, and also, at the same time, a hard-to-remember acronym. At first, the PCMCIA cards were limited to memory cards (as the association?s name suggests), and at first, they represented a standard that wasn?t, as early models were plagued with incompatibilities. Slowly, the standards have been tightened, and now extend to a wide range of hardware, 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 memory cards. Type II sockets can hold two Type I cards or a single 5.5 mm Type 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 created an even thicker Type IV socket-- but this is not yet a widely-supported standard.

Software drivers-- so-called Card and Socket Services (C&SS) need 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 so for each card loaded. While these drivers can be loaded high, this can cause problems running some programs-- especially if you need to load multiple drivers.


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 Panel. It?s a simple matter to turn on support for PC cards.

And once support is turned on, Win 95 supports hot swapping-- adding 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 it. 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 pops up on the TaskBar, and you?re in business. Plug and Play like it?s supposed to be. And sheer magic if you?ve wrestled with installing cards in standard, desktop PCs, under DOS or Windows.

While Warp doesn?t call it Plug and Play, it also has solid working 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 cards, most portables require special, and pricier ram... I wouldn?t recommend four megs on any new computer purchase-- portable or desktop.


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 can be squeezed into the thin metal case. I don?t recommend cutting one open to peek inside, but if you did, you might see ram chips, digital signal processors, and other standard chips-- all neatly soldered onto two sides of a thin board. In fact, everything you need for a standard adapter card... 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 cost $200-250, compared to about half that for a standard modem, while a faster 28.8 modem may cost $400-500 on a PC Card, compared to $250-400 for its larger cousin.

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 capabilities, and all seem to offer fairly similar capabilities-- performing virtually identically to larger models with the same rated speeds. The biggest difference 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 metal shell. Press on the end, and the X-Jack pops out, ready to accept a standard 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 models prefer to include special phone cords, which plug into the end of the PC Card... these may be more sturdy, but if you forget or lose the cord, the modem is unusable.

Modems aren?t the only use for these versatile cards-- almost anything that can be plugged into a standard ISA jack can be miniaturized onto a PC Card. Currently, you can buy SCSI adapters from several manufacturers. 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 10-base-T 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 integrate several cards in one. Combining an Ethernet adapter and a modem into a single card is an example of this.


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, shirt-pocket 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, however. 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 PC Cards.

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 all-in-one modem, network adapter, SCSI card, combined with sound card featuring microphone input and speaker outputs. Wonder where all those plugs are going to go?

PC Cards have outgrown a somewhat awkward adolescence. They now greatly extent the usefulness of our portable computers, making it much more possible for these tiny machines to almost entirely replace the big, lumbering desktop models. Expect to see them popping up wherever people take their computers-- from the office to home, on the road, even on vacation.

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Alan Zisman is a Vancouver educator, writer, and computer specialist. He can be reached at E-mail Alan