The latest PowerBooks set a new standard: built-in Ethernet, a trackpad, optional PCMCIA, 16-bit color, stereo sound, and a fast 68040 CPU upgradable to PowerPC
Tom Thompson
When Apple introduced its Macintosh notebook computers, the PowerBooks, in 1991, it set new standards for what such portable systems should do. The design was termed ``all-in-one'' because these Macs were literally self-contained desktop systems. For example, they had a high-density floppy drive that could read and write PC disks, built-in networking hardware and software, and a slot for an optional internal modem. However, for the past few years, most of the improvements to the design have been incremental, such as faster 68030 processors, an external video port, and color displays. The all-in-one design was becoming long i
n the tooth.
With the introduction of the 500 series PowerBooks this May, Apple not only brought the all-in-one PowerBook design up-to-date but also set new standards. The PowerBooks now use the high-performance 68LC040 processor. Battery life has been beefed up by the addition of a second battery compartment. A new solid-state trackpad makes the computer easier to use. There's substantial capacity for memory and large hard drives, and an Ethernet port boosts the system's network capabilities. An optional PCMCIA Expansion Module fits in one of the battery compartments and lets you expand the PowerBook's functions using third-party PCMCIA cards. What hasn't changed is that the computer still weighs 7.3 pounds, even with a second battery. (It weighs a pound less with one battery.) These capabilities make the 500 series PowerBook a powerful desktop computer in its own right, and therefore a superb notebook computer.
The 500 series PowerBooks come in two families. The low-cost 520 models run at 50 M
Hz, and the high-performance 540 models operate at 66 MHz. These speeds represent just the processor clock rate; the rest of the system runs at half the processor's speed--25 MHz and 33 MHz, respectively. The 520 models sport passive-matrix screens; the 540 models use active-matrix technology.
In addition to the all-in-one systems, there is a new PowerBook Duo, the 280, that uses a 66-MHz 68LC040 processor. I'll make only a few references to the Duo, since it's primarily a Duo 270c design with a new processor. I'll focus primarily on the new features in the 500 series PowerBooks.
What's New Outside
I received a PowerBook 540c and a Duo 280c for evaluation. Both use the active-matrix color display. The 540c came with 4 MB of RAM and a 240-MB hard drive, and the Duo had 12 MB of RAM and a 320-MB hard drive.
Some of the 540c's new features were immediately obvious. Flipping the back panel open revealed an Ethernet port that uses the 14-pin AUI (Apple Auxiliary Unit Interface) connector. T
his connector lets you use your choice of thick, thin, or 10Base-T Ethernet modules to connect the 540c to the office network. There's the usual complement of ports: the RS-422 serial port (which does double duty as the LocalTalk network connection), stereo sound input and output jacks, an ADB (Apple Desktop Bus) port, an external video port (for using a second monitor), and an HDI-30 SCSI port.
The power switch is no longer awkwardly placed among these ports, thank goodness. When you open the PowerBook's lid, you spot the power switch just above the keyboard, a location that makes the computer easy to switch on.
Along the top of the full-size keyboard are 12 function keys and the Escape key (which in previous PowerBook designs was in an awkward position by the space bar). Some of the keyboard layout was borrowed from the PowerBook Duo, and it's nice to see it on the all-in-one design. Another cool feature swiped from the Duo design puts the computer in sleep mode when you close its lid. An LED
in the lid blinks when the computer is asleep.
The active-matrix color display has a 640- by 480-pixel screen. At 9.5 inches diagonal, this display is slightly larger than the 9-inch diagonal on previous color PowerBooks. The Duo 280c still uses an 8.4-inch-diagonal screen.
The 540c's screen is flanked by two small speakers that supply stereo sound. With the new design, you can buy a lower-cost PowerBook 520 with a passive-matrix screen and upgrade it to the 540's active-matrix display later by just swapping the PowerBook lid. However, at $2199, this upgrade isn't cheap.
The biggest visible difference in the new machine is a flat plate that replaces the computer's trackball. This is Apple's trackpad, which uses capacitance sensing to accurately detect and track the motion of a fingertip on its surface (see ``Apple, Cirque Unveil Trackball Alternative,'' June BYTE, page 33). Although the trackpad can sense pressure, Apple opted instead to use a single mouse button for clicking on objects.
Based on my use of the trackpad, it works much better than a trackball for text selection and editing, and it's better suited for drawing. Also, with no moving parts, it's less likely to fail than a trackball. With an active-matrix display, controlling the pointer with the trackpad is quick and precise. However, on a PowerBook 520 with a passive-matrix display, where the pointer disappears or ghosts when it's moved, steering with the trackpad becomes tricky.
Each side of the PowerBook 540c contains a bay for an NiMH (nickel-metal-hydride) battery. (Previous all-in-one designs used nickel-cadmium batteries.) A new power charger cranks out 40 W to charge both batteries if the computer is idle, or one at a time if it's in use. Power is drawn from one battery and then the other, so you can swap a fresh battery for a dead one without turning the PowerBook off.
Apple estimates that the PowerBook 540c can operate on battery power for up to 7 hours, and the Duo 280c for 2 to 4 hours. The BYTE bat
tery-life tests show that with two fully charged batteries, the PowerBook 540c can operate for about 6 hours, and the Duo 280c for about 3 1/2 hours. In personal tests going about my office work, I obtained about 3 to 4 hours' worth of battery life from the 540c--a definite improvement in battery life, especially with a 68040 processor in the system.
What's New Inside
The heart of the 540c is a Motorola 68LC040 clocked at 66 MHz. Because the rest of the system is clocked at 33 MHz, overall system performance should be around that of a 33-MHz system, except in those cases where portions of an application's code reside in the processor caches. Also, since the 68LC040 lacks an FPU, you can expect floating-point math performance to suffer. These expectations are confirmed by the BYTE low-level and application benchmarks: The 540c's performance was about that of a 33-MHz Quadra 950 except in floating-point performance (see the graph). Similar results were obtained on the Duo 280c.
The 500 series P
owerBooks use 2-MB ROMs that contain the Mac Toolbox, plus code that implements power management for the 68040 processor. The computers start with a base 4 MB of 80-nanosecond RAM, and a RAM expansion slot can expand RAM to a total of 36 MB (up to 40 MB on the Duo 280c). The RAM signals and timings for the 500 series PowerBooks differ from those of other PowerBooks, so you can't use existing memory expansion cards. The processor, ROMs, and base memory are located on a removable secondary logic board, which can be replaced with a PowerPC upgrade board. No price or details on the PowerPC upgrade were available at press time.
The frame buffer for the 540c's display now uses 512 KB of dual-ported VRAM (video RAM), rather than DRAM as in older all-in-one color displays. This makes for faster screen redrawing, a fact borne out by the BYTE low-level benchmarks. Timing for the slow graphics test, which was 13 seconds or more with previous color PowerBooks, plummeted to several seconds. Screen updates and docum
ent-scrolling operations were faster, making the system's response noticeably snappier.
A new Display Manager lets you change the screen resolution on the fly from 640 by 480 pixels to 640 by 400 pixels. The smaller screen size enables the surplus VRAM to be used for larger pixels: The screen then shows 16-bit color (actually 24,000 colors, due to limitations in the LCD panel). This makes the PowerBook 540c and Duo 280c suitable for viewing digital video QuickTime clips or scanned images. The color capabilities of this display at this resolution, combined with improved audio (16-bit CD-quality stereo), makes the PowerBook 540c an excellent multimedia computer.
Inside the left battery compartment on the 540c is a 90-pin PDS (Processor Direct Slot) connector, so instead of a battery, you can plug an expansion board into this bay. PDS is a bit of a misnomer here, since the slot is not directly connected to the processor bus. Instead, an interface chip provides 68030 processor signals and timings, m
aking the slot compatible with the Mac LC slot. However, this slot has different power requirements, which must meet the power budget of a notebook computer. Also, the I/O bus that the PDS connector sits on is only 16 bits wide, which constrains the use of any high-throughput peripherals. Whether third-party vendors will make hardware for this slot remains to be seen.
The more interesting use of this bay and the PDS is Apple's PCMCIA Expansion Module. It accepts two stacked Type II PCMCIA slots or one Type III slot. The module shipped in July and costs under $200. You have to switch the PowerBook off to plug the module into the battery bay, but once it's installed the system software allows ``hot docking'' of PCMCIA cards. For example, you can insert a Type III card with a hard drive into the module, and an icon of the drive will appear on the Mac Desktop. You can drag files to the card and then eject the card by dragging the icon to the Trashcan. No motors are required for this: A nitinol (nickel-ti
tanium alloy) wire contracts and ejects the card a good 20 millimeters when current passes through it. The Expansion Module will let you add wireless LAN, cellular modem, flash memory storage, and other mobile options as these cards appear on the market.
Timely Improvement
The Duo 280 systems bring the might of the 68040 processor to the PowerBook Duo line. The 500 series PowerBooks provide a much-needed overhaul for the all-in-one design. Improvements include the function keys, the built-in Ethernet support, and the 68040 processor.
The performance, storage capacity, and RAM expansion limits of these systems make them powerful yet portable knock-around desktop systems and superb notebook computers. However, the design also pushes the envelope with the innovative trackpad, the stereo sound system, and the PCMCIA Expansion Module. When various third-party wireless cards arrive, they should help make the 500 series PowerBook the ideal mobile computer. Finally, this PowerBook has the future buil
t in with a planned PowerPC upgrade. It's safe to say that Apple has once again defined the standards for notebook computers--standards that the competition will be hard pressed to duplicate.
The Facts
PowerBook 520 (with 50-/25-MHz 68LC040,
4 MB RAM, 160-MB hard drive, and FSTN gray-scale display) $2269
PowerBook 520c (with 50-/25-MHz 68LC040,
4 MB RAM, 160-MB hard drive, and dual-scan color display) $2899
PowerBook 540 (with 66-/33-MHz 68LC040,
4 MB RAM, 240-MB hard drive, and active-matrix gray-scale display) $3159
PowerBook 540c (with 66-/33-MHz 68LC040,
4 MB RAM, 320-MB hard drive, and active-matrix color display) $4839
PowerBook Duo 280 (with 66-/33-MHz 68LC040,
4 MB RAM, 240-MB hard drive, and active-matrix gray-scale display) $2639
PowerBook Duo 280c (with 66-/33-MHz 68LC040,
4 MB RAM, 320-MB hard drive, and active-matrix color display) $3759
Apple Computer, Inc.
1 Infinite Loop
Cupert
ino, CA 95014
(800) 776-2333
(408) 996-1010
fax: (408) 974-6412
Photograph: The 500 series PowerBooks (left) provide a much-needed overhaul for the all-in-one design. Improvements include storage and RAM capacity, built-in Ethernet support, an innovative trackpad, stereo sound, a PCMCIA Expansion Module, and a 68040 processor upgradable to PowerPC. The Duo 280 systems (right) bring the might of the 68040 processor to the PowerBook Duo line.
Illustration: Graph: PowerBook Performance
The heart of the 540c is a Motorola 68LC040 clocked at 66 MHz. Because the rest of the system is clocked at 33 MHz, overall system performance should be around that of a 33-MHz system, except when portions of an application's code reside in the processor caches. Since the 68LC040 lacks an FPU, floating-point math performance suffers. These conclusions are confirmed by the BYTE low-level and application benchmarks: The 540c's performance was nearly equal to that of a 33-MHz Quadra 950 exce
pt in floating-point performance. Similar results were obtained on the Duo 280c.
Tom Thompson is a BYTE senior technical editor at large with a B.S.E.E. degree from Memphis State University. He is an Associate Apple Developer. You can contact him on AppleLink as T.THOMPSON, or on the Internet or BIX at
tom_thompson@bix.com
.
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