Market Overview - Notebooks: Weigh to Go

Smaller, faster and longer-running ? notebooks are ready to challenge their desktop cousins. Roger Gann looks at the latest developments

Modern notebooks are a far cry from the machines of a couple of years ago ? there have been tremendous improvements in usability and functions. For the average business user, a top-end notebook can do everything a desktop PC can, with the advantage of portability for work on the road or at home.

Take a typical example of the state of the notebook art, the Toshiba Tecra 740CDT. This features a bright 13.3in XGA screen, a 166MHz mobile Pentium processor with MMX technology, 256Kb level 2 cache, a 2.02Gb removable hard disk, a 10-speed CD-Rom drive and a clip-on video conferencing camera and Zoom Video card that take advantage of the Cardbus and ZV-ready PC card slots. There?s very little you can do with a well-specified desktop PC that can?t be done on a notebook like this.

Compared with the desktop PC market, the notebook market continues to look bright. Sales continue to grow and margins on notebooks remain healthy. The portable market is maturing and is segmenting as a result. As well as the high-end and value notebook ranges, Compaq has paved the way for a new class of notebook, aimed at the home, with the successful launch of the Compaq Presario 1000 range late in 1996.

The sub-notebook range is also exhibiting signs of vigorous growth, with the tiny Toshiba Libretto 20 selling like hot cakes in Japan. It remains a fast-moving, innovative market. This feature looks at upcoming technologies and how they will affect the notebook of tomorrow.

In an attempt to change the way notebooks are designed and to improve standardisation, Intel has announced the first of a planned series of Mobile Modules. These small (2.5 x 4in) cards contain the CPU, level 2 cache and ?north bridge? of the system-logic chip set, bringing all the processor-specific circuitry into a self-contained unit.

As a result, notebook designers who adopt the initial P55C module will be able to upgrade their designs to future Intel processors simply by plugging in a new module. This method short-circuits the extensive design work required by previous processor shifts and should accelerate the appearance of P6 notebooks.

The first product in the line contains a 150MHz or 166MHz MMX Pentium processor, 256Kb of burst SRam for the level 2 cache and the new 430TX PCI set. This is the first mobile chip set to support Concurrent PCI, Ultra DMA, universal serial bus and synchronous DRam.

The benefits of the Mobile Module are in its upgradability. In the past, every notebook system needed a significant amount of design work because of differences in processor pin-out, voltage and power requirements. The first systems designed for the new module will require an equivalent amount of work, but future systems can move to new processors simply by installing a different type of module, as long as Intel maintains the same specifications. But Mobile Module is not a user upgrade in the way that Zif sockets allowed the easy installation of Overdrive processors.

Intel has committed to delivering Mobile Modules for the next three processor generations and this will most likely include the Tillamook (200/ 233MHz MMX Pentium) and Mobile Pentium II (Deschutes) processors, due to be launched next year. Heat dissipation, however, is likely to be a problem with the second CPU.

Today?s notebook screens range from 10.4in to a massive 12.1in on top-end models. These larger screens are not far behind what you can expect from a standard 14in visual display unit, given that monitor measurements are always given as the actual unit?s size and not the visible area, which may be less than 13in.

Furthermore, users generally sit a lot closer to a notebook screen than to a monitor, making it appear larger anyway, and LCDs are more uniformly lit and more evenly focused than VDUs, so they are less tiring to look at. One of the more unusual screens is to be found on the Sharp PC-W100T. Better known as the Widenote, it has a wide-format 9.6 x 5.6in screen displaying 1,024 x 600 pixels.

Although passive matrix/ dual scan and active matrix/ thin film transistor (TFT) displays represent the range of display technologies available, these are under constant refinement. Active matrix is brighter and crisper than passive matrix, and it has a wider viewing angle. Dual-scan screens can only be viewed straight on, and in bright light users still end up squinting to see the screen. They also can?t keep up with fast action.

Displays continue to improve in leaps and bounds. Size, as ever, continues to be important. Currently, the largest screen available for notebooks measures 12.1in, although a raft of 13.3in displays are expected to make their debuts early this year.

Mitsubishi has demonstrated a 14.2in XGA (1024 x 768) resolution screen, a TFT display designed for high-end multimedia notebooks. But to accommodate a 14.2in screen, the traditional 8.5 x 11in notebook form factor will have to be broken.

Toshiba intends to employ a low temperature polysilicon process to manufacture 12.1in XGA LCD screens for notebook computers. This process provides smaller TFTs that block less light. The displays have a 70 per cent aperture ratio, higher than XGA panels that are shrunk to notebook size. The screens don?t require as much power for a backlight and their electron mobility is 10 times higher than amorphous silicon displays. Driver ICs can be placed on the edge of the glass substrate, which reduces the part of the display that is not visible. Low temperature polysilicon was previously confined to the production of the 2in and 4in screens used in camcorder viewfinders.

Size and weight are crucial elements in notebook PC design. While display and keyboard size restrict any further size reductions, extra weight reductions are still possible and most of these can be obtained from new battery technologies.

The demands placed on batteries are significant: advanced notebook components are putting an increasing strain on even long-lasting batteries: Displays for portables have ballooned to 13.3in, processor speeds are hitting 200MHz, and hard disks are breaking the 2Gb ceiling.

Most notebooks use either lithium ion (Li-ion) or nickel-metal hydride (NiMH) batteries. Battery life for all of these PCs is about two to three hours, but constant use of a CD-Rom drive greatly shortens that.

Notebooks powered by nickel cadmium (Nicad) batteries have been rapidly superseded by NiMH ones. A NiMH battery consists of a positive nickel-coated anode and hydrogen-absorbing metal alloy cathode, separated by water/acid electrolyte. It presently offers 33 per cent more life than comparable Nicad cells and there has been a wide uptake of NiMH technology by battery manufacturers. Many notebooks are already equipped with NiMH batteries, which are less toxic than Nicads, but a bit pricier.

Lithium-based batteries were cheap to make but, as lithium is highly reactive, they were prone to explode or catch fire ? NEC had to recall lithium powered Ultralites in the late 1980s. However, it is very light and isn?t toxic. There are two types of lithium batteries: lithium polymer and lithium ion.

Lithium polymer batteries were developed by Valence Technology and use a lithium metal foil cathode and a metal oxide compound anode, separated by a flexible solid polymer, not a liquid, so no heavy sheathing is needed. The battery?s thin, flexible form allows it to be shaped to intimately fit the available space in a portable.

The rival lithium ion technology was developed by Bell Communications Research: it tempers lithium?s volatility by using graphite compounds. Because lithium

discharges more slowly than NiMH, notebooks will run 10 to 20 per cent longer between charges. Also, the chemistry of the lithium ion battery makes it more suitable for building a ?smart? battery that can display the amount of charge left.

Of the two, lithium polymer has the edge in duration, offering about 50 per cent more life than lithium ion. But lithium polymer has yet to come to the market.

As well as being green, lithium technology offers a much greater energy density than Nicad at half the weight, with three to four times as much life and reduced memory effects. Although pure lithium has shorter recharge life, at about 300 cycles, recycling at 50 per cent of its discharge can triple this. Lithium ion is better in this regard and lasts three times as long as Nicad and can be recharged over 1,000 times.

Perhaps the most attractive battery technology of all is zinc air, which promises at least four times as much energy per pound as Nicad. Zinc air uses a mesh of metallic zinc, which is exposed to air. As the zinc oxidises, it releases electrons to an external circuit. By controlling airflow, the current flow can be varied, so it needs plenty of air.

The beauty of zinc air is that half of its chemical requirements are fresh air. It may be light, but it?s also very bulky. It also takes a long time to recharge ? two hours of recharge for every hour of life. Zinc air suffers from no memory effects and will offer a very long life, perhaps as long as 12 hours for a notebook.

Power management is just as important. In January, Intel, Microsoft and Toshiba America released version 1 of their jointly developed active configuration power interface (ACPI), which supports the smart battery system (SBS) specification and the system management bus (SMbus). Microsoft will embed some of the technology in Windows 97 and supporting application software will follow. ACPI will intelligently offload many advanced power management tasks to the operating system, turning off different parts of the notebook based on predefined conditions.

The smart battery initiative is especially interesting. O2 Micro has demonstrated a two-battery system that allows an exhausted battery to be replaced without the need to power down. Duracell is contemplating setting up battery swap shops near major US airports, where exhausted batteries can be exchanged for fresh ones for a fee.

Another interesting development is the heuristic power management (HPM) technology found in a few high-end notebooks, such as those from Acer. HPM technology is able to recognise specific computing use patterns and adjusts its power distribution pattern to maximise battery life. ACPI will incorporate support for HPM.

Advanced I/O infra-red data transfer (IRDA) ports have become a common sight. You?ll find the original 115Kbps IRDA port on many notebooks and the 4Mbps IRDA-2 or Fast IR port in newer models. Some notebooks sport infra-red ports on front and rear panels to make beaming data to a palmtop or other device less awkward.

This year should also see the universal serial bus (USB) port on many notebooks. With a 12Mbps bandwidth, USB will allow the daisy-chaining of dozens of compatible peripherals, from mice and keyboards to possibly printers, scanners, modems and monitors.

Floppy disk technology

While many current notebook designs omit or make the humble 1.44Mb 3.5in floppy drive an optional, swappable extra, a battle over the notebook super floppy turf is raging. Mitsubishi is offering slim, 12.7mm versions of its LS-120 format disk drive for use in notebook computers from the summer. The LS-120 is a next-generation floppy disk format offering 120Mb of storage and with the advantage of backwards drive compatibility with current floppy disks.

Meanwhile, a suitably anorexic version of Iomega?s popular 100Mb Zip drive is being readied for release at much the same time. Iomega?s new notebook design is slated to be just 12.7mm thick. Already, Iomega has announced a 15mm thick internal Zip drive for laptop computers.

Other trends

The latest fashion statement among portables is ultra-slim notebooks, typified by Digital?s Hinote Ultra and Fujitsu?s Lifebook, which are just over 1.5in thick. This new breed addresses a growing need within organisations for more portability than bulkier notebooks offer. Often it?s a case of weight and size. These ultra-slim notebooks appeal to executives simply because they can fit in a briefcase.

Many new notebooks now offer empty drive bays that can take either a removable floppy or CD-Rom drive or an extra battery, depending on needs. Swapping components takes seconds and can sometimes be done without powering down. Unfortunately, bay size and electrical connections are not yet industry standards, like PC card slots, so drives are not interchangeable among machines.

A surprising number of desktop devices can be plugged in to today?s notebooks. Component bays for interchangeable floppy, CD-Rom, hard drives, and extra batteries tend toward the high end, but almost all notebooks offer a pair of PC card expansion slots, usually stacked to accommodate two Type II cards or one Type III card.

Cardbus slots ? a new generation of slots that accept both existing 16bit PC cards and faster 32bit Cardbus cards ? are finally appearing in high-performance portables. Another PC card specification to watch for is Zoomed Video (ZV) support, which can be part of either 32bit or 16bit slots and cards. The ZV spec provides a path for add-on cards such as Mpeg decoders to directly access audio and video controllers.