PCs acquire Macintosh-like expandability

PCs acquire Macintosh-like expandability, using resources that were there all along

As somebody who mostly uses PCs, I find one of the nicest things about Macs is the SCSI port. Yet another awful computer acronym, SCSI is pronounced "scuzzy," and stands for "Small Computer System Interface." Apple started adding it to all Macs starting with the Mac Plus model, back around 1986 or so, because it solved a problem that afflicted the early models: cute as they were, it was just about impossible to hook up new hardware to them.

The original IBM PC was designed with slots--you could change the video from monochrome to colour, add a hard drive, a modem, whatever. Open up the box, add a card to an expansion slot, and presto! But the original Mac was a sealed unit--no slots, and thus, no easy way to add hardware.

Recognizing this problem, Apple added the SCSI port to later models, providing instant expandability. So now, you can simply plug any external SCSI hardware unit into the port, add a software driver, and you're ready. Not surprisingly, a wide range of SCSI devices have become available--hard drives, removable Syquest drives, scanners, tape backup units, CD-ROMs--all easily added via the SCSI port. And while SCSI has its own complications, involving SCSI ID numbers and termination, it is far, far easier to configure than the mysteries of IRQ and DMA conflicts that are too often involved in trying to add hardware to a PC. And you don't need to open the case. You can even attach up to seven SCSI units, on a single port, daisy-chained one to another.

SCSI has been available for PCs for years, but has had limited acceptance, mostly limited to adding high-capacity hard drives to network servers. It has never caught on widely: because it's not built into the system the way it is in all current Macs, many view it as just another level of complication for a hardware system that's already too complicated. As a result, SCSI units for PCs typically end up costing more than the more widely distributed alternatives, making it even less likely that SCSI will catch on as a PC standard.

But the advantages of expanding your computer by simply plugging an external unit into a port are hard to ignore. Instead of SCSI, more and more manufacturers are taking advantage of the ports that the PC already has--the serial port and the parallel printer port. Mice and external modems have always been able to plug into your PC's serial ports, and of course, printers have been plugged into the parallel port. Recently, however, a wide range of options have become available that simply plug into the back of the PC--no opening the case, no muss, no fuss.

Take digital cameras: units ranging in price from several thousand dollars for a digital Nikon to about $1,000 for units from Apple or Logitech, or to $140 for the very hip Quickcam, all plug into a free serial port. But even more options can make use of the parallel port. With eight lines in to the computer, compared to one line in a serial port, the parallel port has always provided the possibility of higher speed and performance. Parallel-port tape-backup units such as MicroSolution's Backpack or Iomega's Ditto take advantage of simple design to sell for under $275. And because they don't require any dedicated cards, they can be moved easily from computer to computer.

Suddenly, there are even fewer reasons to avoid backing up your computers regularly. Iomega's Zip drives let users choose from parallel port or SCSI versions of these popular 100-meg disk drives, again gaining the ability to plug into any computer with a matching port. That isn't all: parallel-port CD-ROMs offer the same advantages, and may offer better performance for portable computers than an added PC-Card SCSI adapter and SCSI CD-ROM.

Users of portables can even come into the office and connect to the network using GVC's $230 parallel port Ethernet adapter. Or for $300, Play Inc.'s Snappy video-grabber lets users capture stills from video sources--TV cable, VCRs, video cameras.

You can even get the equivalent of a sound card, plugged into the printer port. And most units include pass-through capability, allowing users to use their printer at the same time, or to plug multiple gadgets onto a single port.

It's not a perfect solution, however (and a PC still isn't a Mac). There's not as much variety in parallel-port devices as there is in the more traditional PC plug-in cards. Prices remain relatively high. And some users may find that their printer ports don't work as advertised: some gadgets require bi-directional printer ports (that both send and receive signals) and some computers' printer ports are send-only.

Even with a bi-directional port, many lower-priced cables are only wired for one-way transmission. (Most problems users are having with these devices are caused by their cables.) So be sure you can return a gadget if it won't work with your system.

Even with these quirks, the growing range of parallel-port devices offer PC users one more thing that Mac users have taken for granted for years--devices that they can install without having to take apart their machine, and that can be easily carried from computer to computer.