Bah Humbug! Don't let creaky PC designs spoil the holidays

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 his 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 any wrong movement.

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 typically 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 times greater?but are still hobbled with the same basic architecture?parallel and serial ports, limited to the number supportable by the AT, an ISA bus (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 printers: scanners, Zip drives, tape backup, CD-RW drives and more. The amazing thing is that most of the time, it kind of works, too! But a printer port isn?t 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 few 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 USB?a technology that sounds like a breakthrough?at least on paper.

The promise is pretty good?connect up to 128 devices, without having to worry about the issues like ID #s and termination that make older technologies like SCSI difficult to use. Hot swap devices?plug them in or remove them 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 late in 1996?three years ago, operating system support has been half-hearted. 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 service packs updating 1996?s NT 4.0 (which should have had USB support but didn?t). NT users have to wait for Windows 2000, to get OS-level support four years 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 Macs. 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 after 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 under 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 systems 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 800 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 cameras and more becoming increasingly common on that platform.

And get this?Apple first drafted the specifications in 1987! Twelve years ago! It was approved in 1995 as IEEE 1394?a memorable name, indeed, while Apple trademarked the FireWire name, and offered to license it for 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 models. And Microsoft is finally offering OS-level support in Win 2000 and Win98 OSR1. To get around Apple?s trademark, don?t look for the name FireWire, and who can remember IEEE 1394? Instead, think of HPSB?High Performance Serial Bus.

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 are styled after those on the Nintendo GameBoy, offering high performance and 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 support 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, that?s one out of a very limited supply. And expect years of teething pains?inconsistent implementation between manufacturers, for example. Even today, Sony?s hardware 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.