Bah Humbug! Don't let creaky PC designs spoil
by Alan Zisman
(c) 1999. First
published in Canadian Computer Wholesaler, December 1999
I?d like to end this year?s run of Techtalk columns
with a traditional
Christmas greeting: ?Bah, humbug!? as Scrooge was known to say before
conversion to sweetness and light.
No, I?m not aiming it at the year-end festivities
(though my family
might disagree), but at a PC architecture that is looking more and more
like a house of cards that is about to come crashing down on us with
Remember, we?re still building on the basic design of
1984?s IBM AT?a
model that refined the company?s 1981 PC, giving it the 16-bit ISA bus
and 16 IRQ interrupts, to service a computer built around an Intel 286
processor running at a blazing 6 MHz, a 20 meg hard drive, and
shipping with 512 kb of RAM.
Today?s computers are running processors at up to 100
times the clock
speed, with hard drives and RAM that are anywhere from 500 to 1000
greater?but are still hobbled with the same basic architecture?parallel
and serial ports, limited to the number supportable by the AT, an ISA
(yes, alongside a modern PCI bus), and those same 16 interrupts.
We?ve been pushing the limits of the design in a lot
of other ways besides
just making it go faster or bigger. Think of all the gadgets that your
customers have been hanging off their printer ports?in addition to
scanners, Zip drives, tape backup, CD-RW drives and more. The amazing
is that most of the time, it kind of works, too! But a printer port
a SCSI port?it?s really not designed to daisy-chain all this stuff, and
not surprisingly, it can get pretty problematic.
And many new PCs arrive right out of the box with all
the IRQs (interrupts)
in use, making expansion difficult, even though most have at least a
free slots on the motherboard.
Even when the industry tries to break through all this
with new technology,
we hobble ourselves by adding it onto this limited old design. Take
technology that sounds like a breakthrough?at least on paper.
The promise is pretty good?connect up to 128 devices,
to worry about the issues like ID #s and termination that make older
like SCSI difficult to use. Hot swap devices?plug them in or remove
while the computer is up and running. Pretty cool!
The reality has been somewhat less exciting. Partly,
it?s been a lack
of system-wide support. While USB ports started appearing on most PCs
in 1996?three years ago, operating system support has been
There was a USB add-on to Windows 95B, but Microsoft only got it right
in Windows 98. NT still lacks USB support?even after a series of
packs updating 1996?s NT 4.0 (which should have had USB support but
NT users have to wait for Windows 2000, to get OS-level support four
after the ports started appearing on their PCs.
And even with that support, it?s still an
after-the-fact add-on. Take
USB keyboards, for example. A nice idea, that works well on the newer
Some models include additional USB ports right on the keyboard, letting
them replace a hub.
Plug one into a PC, and it will work nicely?if you?re
using Win98. And
since the USB support is loaded as Win98 boots, you have a problem?what
happens if you need to boot to DOS? Or press the F8 key to choose Safe
Mode at bootup? Or respond to error messages when Scandisk is running
a system crash? Oh sorry?your keyboard may not work yet.
Even if your keyboard?s OK, we?re trying to push more
bits through those
USB ports than its 12 Mb per second bandwidth will support. Toss in USB
networking. And USB sound and speakers (oh, you wanted to hear sound
DOS, too?), and USB modems (and promised cable and DSL modems). And try
to make them all work at once? I don?t think so!
There is a promise of a USB-2 standard, supporting up
to 300 Mb/sec?
which means a few more years of waiting for hardware and operating
standards to stabilize.
Then there?s FireWire?otherwise to be referred to as
the standard otherwise
known as? FireWire is the name that creator Apple uses for a high-speed
port standard?400 Mb/sec with the potential of going to a blistering
Mb/sec. It?s available now on high end Macs, including some of the new
consumer-oriented iMac models, with Firewire hard drives and video
and more becoming increasingly common on that platform.
And get this?Apple first drafted the specifications in
years ago! It was approved in 1995 as IEEE 1394?a memorable name,
while Apple trademarked the FireWire name, and offered to license it
a fee. Sony has included a non-standard variation of IEEE 1394 on some
of its models, calling it i.Link (also trademarked), and promoting its
potential for connecting to the company?s video cameras. And Compaq has
offered more standard support over the years. But Intel has not offered
chip-set level hardware support in any of its existing or announced
And Microsoft is finally offering OS-level support in Win 2000 and
OSR1. To get around Apple?s trademark, don?t look for the name
and who can remember IEEE 1394? Instead, think of HPSB?High Performance
Widespread HPSB support will be great?support for up
to 63 devices,
hot swapping, and the promise of real-time high speed performance that
even USB 2.0 cannot attain. (A bit of FireWire trivia?the connectors
styled after those on the Nintendo GameBoy, offering high performance
small size). Even without Intel support, you can add HPSB to a PC now,
for example, with Adaptec?s AHA 8940 card?though even here, Adaptec?s
has been on-again/off-again.
But still yet another add-on to the creaky AT
architecture. Even though,
like USB, it only needs a single IRQ to support multiple devices,
one out of a very limited supply. And expect years of teething
implementation between manufacturers, for example. Even today, Sony?s
may or may not work with other manufacturer?s 1394 ports.
Enough of my humbugging, though. Enjoy the
holidays?more Techtalk in
the new year.