expandability, using resources that were there all along
by Alan Zisman (c) 1995 First published
in Business in
Vancouver , Issue #321 December 19, 1995 High Tech
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
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.
Apple added the SCSI port to later models, providing instant
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,
easily added via the SCSI port. And while SCSI has its own
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.
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
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.
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.
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
of higher speed and performance. Parallel-port tape-backup units such
as MicroSolution's Backpack or Iomega's Ditto take
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
even fewer reasons to avoid backing up your computers regularly.
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
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.
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
It's not a
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.
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
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.