IBM PC AT; state of the art technology enhances the PC. (evaluation) Russ Lockwood.
The IBM PC is one of the biggest success stories of the microcomputer industry. Within three years, it has come to dominate the industry, making the 8088 microprocessor and MS-DOS operating system de facto standards and PC compatibles all the rage. Even as its architecture aged and faster, more powerful machines entered the marketplace, the PC rode IBM quality and recognition into the sales record books.
What could IBM do for an encore? We mean a real encore, not just rebundling the system as an XT, jr, or portable. Something that would improve upon the PC in the way that the PC improved upon 8-bit machines.
Well, the folks at IBM have done it again, and in a big way. The press releases call the new machine the IBM Personal Computer AT. We call it dynamite. AT: Something to Phone Home About
Contrary to wishful thinking, the AT acronym does not stand for Alien Traveller. It does stand for Advanced Technology, which is bland but certainly descriptive. IBM has created a state-of-the-art microcomputer--at a top-of-the-line price.
Like the PC, the AT consists of three components: a display, a detachable keyboard, and a system unit housing the cpu, disk drives, and all the electronic innards of the systems. System Unit
The heart of the AT is the 16-bit Intel 80286 microprocessor, which is a couple of leaps ahead of the 8088, yet fairly compatible. The AT uses a 16-bit external data bus interface, has Basic in ROM (64K expandable to 128K), and can hold up to 3Mb of RAM. The 80286 operates at 6 Mhz, and combined with the 16-bit data paths, makes the AT two to three times faster than the PC.
For example, compare the results of Ahl's Simple Benchmark Test for the PC and the AT in Table 1. At nine seconds versus 24 seconds, the test bears out IBM's speed claims.
The AT motherboard normally holds 256K RAM, but you can use special piggybacked 64K chips to increase capacity to 512K RAM. This method of palcing more RAM on the motherboard seems like an interim solution to the shortage of 256K chips. IBM notes that 64K chips cost less than 256K chips.
Whatever the reason for the piggybacked 64K chips, give IBM three cheers for eliminating most of the DIP switches on the motherboard. The AT uses a short installation program in CMOS RAM to set up a particular hardware configuration. This CMOS RAM also contains a clock/calendar. A removable GE lithium battery attaches to the rear wall of the system unit by a velcro strip, so changing the battery is quick and easy. The one switch left on the motherboard determines whether you use a color monochrome monitor. Adding Things
For fast number crunching, the AT supports the 80287 numeric co-processor, an advanced version of the 8087 you can place in the PC.
The AT has eight expansion slots, two with the 62-pin card edge socket (8-bit) found in the PC and six with dual 62-pin and 32-pin sockets (16-bit). What this means is that expansion boards for the PC may not fit in the AT. It all depends whethr the boards have a "skirt" that hangs lower than the connector. If a skirt is present, as on the IBM graphics board, you must place it in one of the two expansion slots with only the 62-pin socket. If the board has no skirt, you can fit it in any of the eight slots.
IBM offers two RAM expansion boards for the AT. One holds 128K and is used to bring the computer up to 640K, which is the limit addressable by DOS 2.0 and 2.1. The other holds 512K and is used only in conjunction with the Xenix operating system, Microsoft's version of Unix.
IBM plans to sell a Prototype Adapter, which is a blank circuit board, for third party development. Fire Up the Converters
The AT uses a 115/230 volt "worldwide" power supply that you can switch between 60 Mhz and 50 Mhz. Thus, if you take the AT to a foreign country, you do not need to purchase a power adapter. You must, however, buy a specific cable for the specific country in which you plan to use it.
To keep cool, the AT uses a variable speed fan. The hotter the AT gets, the faster the fan goes. This design also reduces the noise of the fan, making for a generally quieter work area.
Every security conscious, the AT has a keylock to prevent unauthorized access to the machine. The lock performs three functions: it locks the cover on the machine so no one can open the system unit; it prevents entering information from the keyboard; and it prevents rebooting of the computer.
Furthermore, you can lock up the computer while it runs a program, which ensures that no one will accidentally stop or alter your program if you step away from your desk. While this will not stop a thief from carrying the entire computer away, it will stop those who simply want to play with the system.
You can place the system unit on a desk or use a floor stand to stand it upright on the floor. The AT has a rotating nameplate. Thus, whether on the floor or on the desk, you can be sure that the IBM logo will be right side up. Those guys think of everything. Megadisk Drive
The system unit holds three disk drives, two half-height 5.25" floppy disk drives, and one full-height Winchester drive.
IBM offers two kinds of floppy drives. The first is the new 1.2Md double sided high capacity drive, which comes standard on the AT. We could not figure out who manufactured it, but it is made in Japan. It is upward compatible, which means you can read from and write to 160/180K and 320/360K formatted disk (i.e. those used with the PC). However, if you use a high capacity drive to write to these disks, that information can only be read by a high capacity drive.
Anticipating the problem of swapping disks between an AT and PC, IBM also sells a double sided 360K capacity floppy drive, distinguished by an asterisk on the front. Both drives are very easy to install, and the drive controller and power supply connectors fit togethr only one way.
Both drives uuse sturdy rotating knobs rather than flip-up doors and contain a locking mechanism to hold the disk in. When you push the disk in, the drive locks it into place. You rotate the knob down to secure it, and when you rotate the knob up, the disk pops out.
Actually, the AT looks as if you could install a third half-height drive, although it would have to be a Winchester drive because the system unit cover blocks access to it. The disk drive controller board, which controls floppy and hard drives, has four connectors.
An optional 20Mb Winchester fits next to the floppy drives, providing more than enough storage for most users. AT Last, A Standard Keyboard
Ironically, IBM, designer of the standard Selectric typewriter keyboard, has been plagued by problems with its microcmputer keyboards. We have documented the fortes and foibles of the Pc keyboard and blasted the old PCjr "Chiclet keyboard. With the AT keyboard, we are fast running out of nits to pick.
The touch and feel of the AT keyboard is identical to that of the PC keyboard--good and solid with a comforting clicking sound. The layout is refreshingly standard, which is a boon to touch typists. The misplaced backslash key is banishd to a spot above the Return key, which is now labeled Enter. This Enter key is located above the righthand Shift key, displacing the infuriating tilde key.
The Shift keys are larger and the Enter key is much larger than their counter-parts on the PC keyboard. After all this time, IBM has finally labeled them in English, although the arrows are kept as well. The spacebar is separated from the Alternate and Caps Lock keys.
Green LED lights, indicating that the Caps Lock, Num Lock, and Scroll Lock keys are toggled on, are located above the numeric keypad. The numeric keypad, which still does double duty for cursor control, has its own Enter key. The Escape and print Screen keys have been moved to the numereic keypad and IBM has added a System Request key as well. This key is used for programming and allows you to run applications concurrently.
Perfect, right? Well, almost. To make room for the backslash key, IBM shrank the Backspace key. If you use this key often, you are likely to end up pressing the backslash key. And there are still no raised bumps on the J, D, and 5 keys. Finally, English labels are still missing from the Backspace and Tab keys. That's all folks. IBM has manufactured a magnificent keyboard.
Better yet, the AT keyboard can be configured in different languages, including French, Italian, and German.
One last plus for the detachable keyboard. It is connected to the system unit with a nine-foot long coiled cord, offering a great deal of maneuverability and convenience. AT Display
IBM has beefed up its color graphics for the AT. You can choose from three different sets of monitors and graphics boards: the standard Color Display and Graphics Adapter (four colors from a 16-color palette) that first came out with the PC; the Enhanced Color Display and Enhanced Graphics Adapter (16 colors from a 64-color palette); and the Professional Graphics Display and Professional Graphics Controller (256 colors from a 4096-color palette). The Enhanced Graphics Adapter also supports graphics on the IBM Monochrome Display, and IBM sells a Graphics Development Toolkit to assist programmers in designing graphics applications. Operating System Upgrade
First, the good news: The AT comes with a new version of PC-DOS. Now the bad news: It is not the multi-user, multi-taskihng operating system we were expecting.
DOS 3.0 is an enhancement of DOS 2.1 and contains a few new commands, including:
Attrib: Marks a file as read-only, protecting files from revision or erasure. It can be removed.
Country: Includes a country in the date and time format.
Device: Allows you to set up RAM disks.
Fcbs: Opens a designated number of file control blocks for concurrent use.
Label: Lets you add, delete, or change the volume label on the disk.
Lastdrive: Sets the maximum number of disk drives you can access.
Select: Lets you choose a foreign keyboard layout.
Share: Brings you to the fringes of networking with file sharing, but these "hooks" are not single-user, multi-tasking options.
Other enhancements include support for the high capacity drives. Xenix Gets a Big Boost
The AT will run Xenix, Microsoft's version of the Unix Time Sharing System. Xenix allows both single-user and multi-user configurations and lets you run several programs at once. It just happens to support memory up to 3Mb, which is what the AT holds.
However, you will have to wait a bit to buy Xenix and other networking options. IBM plans to release Xenix, a network program, an SNA 3270 emulation program, and a multi-tasking windowing program called Topview in the first quarter of 1985. Networking Hardware Ready
As usual, software development lags behind hardware. IBM already sells the networking hardware. We did not have the hardware installed on our machine and could not make any determination on how easy or hard it is to install and operate. We can give you an overview of what IBM offers.
Network Adapter: An expansion card links the AT, PC, XT, and Portable PC to the PC network. One adapter is needed for each computer. The adapter does not work with the PCjr.
Network Translator: A stand-alone unit supports up to eight stations without additional components, up to 72 stations within a 1000-foot radius with IBM networking cabling, and up to 255 stations within 1000-foot radius with custom cabling (not offered by IBM).
Network Base Expander: Increases the capacity of the translator from a maximum of eight stations to a maximum of 72 stations.
Network Kits: Increases the maximum distance between translator and stations. Short up to 200 feet, Medium up to 600 feet, and Long up to 1000 feet. Software Compatibility
For the AT to become a complete success, it must be able to run much of the software available for the PC. IBM has released a list of program that run on the AT. These include Peachtree accounting programs, Dow Jones Reporter, Multiplan, VisiCalc, Easywriter, and 56 others. So far so good. But IBM has also released the names of 11 programs that do not work on the AT.
So we grabbed an assortment of software off the shelf and started testing, in part to see if the 1.2Mb floppy drive would read the disks, but mostly to evaluate compatibility.
Programs written in Basic for the PC ran without a hitch, which makes sense since Basic 3.0 bundled with the AT contains only minor differences from Basic 2.0 bundled with the PC. Many business packages, including word processing and graphics programs, also worked without a hitch.
One curious result of our testing was an "insufficient memory" message when we tried to install WordStar. Our AT had 640K RAM, yet the installation program refused to believe that it was there. We never did get WordStar to work, but we learned that WordPerfect works quite well.
Of course, the biggest test of PC compatibility is running Lotus 1-2-3 and Flight Simulator. Unfortunately, the AT ran neither. We could start Flight Simulator, but the program soon froze.
All in all, a little more than half of the PC software we tried on the AT ran without problems. Some loaded fine, but bombed out during operation. Some would not load at all. Our best advice is to try your favorite software first. Documentation
IBM ships three manuals with the AT: Installation and Setup Manual, Guide to Operations, and Basic Reference Manual. Three other manuals are available: Technical Reference, DOS 3.0, and Hardware Maintenance volumes 1 and 2.
All manuals are in three-ring, loose-leaf binders, making updates neat and easy. Overall, the documentation is clear, well-illustrated, and easy to follow. The Price of Power
The AT carries a pretty steep price. An AT with 256K RAM and one 1.2Mb floppy drive goes for $3995. The enhanced model, with 512K RAM, one 1.2Mb floopy drive, one 20 Mb Winchester, and a serial/parallel expansion board costs $5795. And that does not include the monitor.
The 512K RAM boards are $1125; teh 80287, $375; the floor standing enclosure, $165; the network adapter board, $695; and the network translator, $595. Additional hardware is just as pricey.
The Professional Graphics Display sells for $1295; the Professional Graphics Controller for $2995; the Enhanced Color Display for $849; the Enhanced Graphics Adapter for $524; and the Graphics Development Toolkit for $350. To Buy or Not TO Buy
We think the AT is a worthy successor to the PC. The state of the art technology--80286 microprocessor, 80287 numeric co-processor, 3Mb capacity, and 1.2Mb floppy drive--make the AT very attractive. The little touches--CMOS RAM instead of DIP switches, keylock, variable speed fan, multi-lingual keyboard, layout, nine-foot long keyboard cord, and "worldwide" power supply--add to its allure.
On the other hand, we were disappointed with other aspects, such as piggybacked 64K chips, only two PC compatible expansion slots, and lack of full networking capability in DOS 3.0.
Although we did not sample the enhanced graphics capability of the AT in action, we certainly appreciate that the option is available.
Of course, price is a major consideration. We would have liked to see much lower prices. Right now, the AT aims for Fortune 1000 and well-to-do professionals, and unless price come down dramatically, we do not anticipate the market penetration that the PC enjoys. For example, you can buy two PCs for the price of one AT. Then again, you can buy many PC compatibles for the price of one AT.
Furthermore, for those thinking of purchasing an AT and hooking up a network of PCjrs, forget it. The PCjr does not support the adapter board. We think the third party manufacturer who comes up with a system to allow a network of PCjrs to run off an AT will find a waiting market.
We think the AT is a dynamite machine. We think IBM is heading in the right direction, but is not quite there yet. When IBM comes out with a full networking software package, the AT will sell well. If IBM sells it at a more competitive price, AT sales may just take off. If they offer a way to hook PCjrs to a network, PCjr sales will increase too.
The biggest question facing prospective buyers is whether the technology is worth the increased cost. For most individuals, AT power represents overkill. Small businesses can probably get by with PCs. Offices considering setting up a local area network should keep the AT in mind, and seriously consider it once the networking package is available. Multinational corporations can not go wrong in buying the AT. The AT is a state of the art machine at a top of the line price.
Products: IBM PC AT (computer)