Zenith Z-151; choice of U.S. Air Force and Navy. (evaluation) Russ Lockwood.
When Uncle Sam announced his intention to spend your tax dollars on a microcomputer, the competition among manufacturers must have been fierce. In the end, Zenith came out the winner, with a $99.8 million order for 10,500 Z-151 desktop computers specially modified for use by the U.S. Air Force and Navy in high security "Tempest" applications. While you cannot buy the military model, you can own the consumer version of the Z-151, an excellent IBM PC compatible.
Like other desktop compatibles, the Z-151 consists of three components: a display, detachable keyboard, and system unit housing the cpu, disk drives, and electronic innards of the system. In terms of style, the Z-151 looks like a piece of military hardware--a touch too boxy. It is certainly not as sleek as some other computers that pass through our office. But before you judge this computer by its system unit cover, know that it is as close to an IBM PC as you can get without copyright infringement.
It uses an 8088 microprocessor, supports an 8087 numeric co-processor, runs MS-DOS, and comes with 128K RAM (expandable to 640K), two serial ports and a parallel port, and two 5.25" 360K floppy disk drives. An optional 10.6Mb Winchester hard disk drive can replace one of the floppy drives.
The left half of the Z-151 system unit holds eight expansion slots, of which four contain the CPU board, graphics board with NTSC and RGB ports, floppy disk drive controller board, and RAM board with 128K (expandable to 320K). This leaves four slots open for other expansion boards. If you buy the hard disk version, the drive controller board occupies one of these open slots.
The detachable, slant-adjustable keyboard is a work of art, for Zenith chose to improve the IBM PC keyboard rather than mimic it. The keyboard is completely electronic, and the tactile feedback is rather good. The aural feedback, a subdued electronic click with each stroke, is acceptable when typing: one key, one click. But if you move the cursor a lot, this can really grate on your nerves.
The ZVM-133 RGB monitor has a dot pitch of 0.41mm, slightly better than the IBM Color Display. The big difference is a button that transforms your color display into an easy-on-the-eyes green screen. (See our February 1985 issue for a full explanation of the intricacies of RGB monitors.) This can be a boon to those who want monochrome for word processing and color for other applications.
Zenith includes a three-ring, loose-leaf owner's manual with information on using MS-DOS and GW-Basic.
Zenith claims that the Z-151 is highly compatible with the IBM PC and runs most off-the-shelf IBM PC software. As evidence, they include a list of 131 packages that were tested and "believed to be generally compatible with today's IBM PC."
Heading the list is Lotus 1-2-3, which also happens to be the de facto standard of IBM PC compatibility. The Z-151 ran version 1A with absolutely no problems. Buried in the list is the other paragon of PC compatibility, Microsoft Flight Simulator. Again, the program ran perfectly.
In fact, a wide variety of business, education, and entertainment programs ran without error and seem to indicate that the Z-151 runs just about everything except for some Basic programs written for the IBM PC.
Thus, we reiterate our standard line regarding the IBM PC compatibles: try the package you want to use before you buy the computer. Based on the Lotus 1-2-3 and Flight Simulator tests, we feel confident that the Z-151 will run most software.
The base model with 128K RAM, one 360K floppy drive, one parallel and two serial ports, and a graphics board costs $2199. The 320K RAM, two floppy drive version sells for $2699. The 320K RAM, one floppy drive, and one 10.6Mb Winchester drive model retails for $3899. All models include MS-DOS and GW-Basic.
The ZVM-122 monochrome monitor sells for $139.95, and the ZVM-133 RGB color monitor sells for $309.
Zenith has recently expanded its line of IBM PC compatible computers. The new offerings are:
Z-138: A 24-pound transportable with built in 7" amber display, which retails for $2099 for 128K RAM and one floppy drive and $2399 for 256K RAM and two floppy drives.
Z-148: An entry level system for home, office, and school. Costs from $1899 to $2199.
Z-158: An enhanced version of the Z-151, which includes a "turbo" switch to boost operating speed by 60%. The 128K RAM, one drive machine retails for $2499; the 256K dual drive model, for $2899; and with a 10Mb hard disk drive, for $4099.
Z-200: An IBM PC AT compatible with 512 K RAM and one 1.2Mb floppy drive. Retails for $3999.
A Final Salute
Give Zenith a medal for manufacturing an Excellent IBM PC compatible. The Z-151 combines terrific IBM PC compatibility, competitive price, and an excellent keyboard layout. Zenith Data Systems, a major manufacturer with commitments to the U.S. government, will support and service their computers for a long time to come. Business people and professionals looking to purchase a microcomputer would do well to check on the Zenith Z-151.
Products: Zenith Z-151 (computer)