Zenith first made a name for itself in the 1920s as a maker of radios, when it was called Zenith Radio Corp. Later, it would be a major producer of televisions and other consumer electronics. In 1979, it entered the computer business with the purchase of Heath Company from Schlumberger.

Heath produced several computers that were popular with engineers and hobbyists, and Zenith began selling one of them, the H-89, under its own brand as the Z-90. Zenith-branded systems were sold through retailers and value-added resellers, while Heath systems were sold via mail-order. This practice would continue through the 1980s. While Heath usually offered kit versions of its computers, all Zenith systems were sold already assembled.

The Z-100 was an appealing bridge system for developers and businesses transitioning from CP/M to MS-DOS. Its dual processors supported both operating systems (MS-DOS in the form of Zenith’s licensed version, ZDOS).

A high level of PC compatibility and sold construction were the Z-150’s main selling points. Zenith introduced the Z-159, a lower-priced version of the Z-158, in February 1987. It offered EGA video standard and accepted EMS memory chips to boost on-board capacity to 1.25MB.

In terms of technical specs, the Z-200 was typical of many PC AT-compatibles. However, Zenith had a deserved reputation for well-engineered and well-built systems.

Zenith’s first portable was the Z-138 PC transportable, followed shortly by the Z-160. The disk drive bays on the Z-160 pop up from the top. The Z-171 had a “lunchbox” form factor and was the same system, with minor differences, as the Morrow Pivot and Osborne Encore. A Z-175 model featured a backlit LCD.

In the late 1980s and early 1990s, Zenith produced some of the best laptop and notebook computers available, including the SupersPort and MinisPort series. They have minimal collector value today, but are bound to be of interest in the future.

Zenith Z-90 (desktop)
Base Configuration: 64K RAM, integral monochrome CRT, integral keyboard/keypad

Zenith Z-100 All-In-One/Z-100 Low Profile (1983, desktop)
Original Retail Price: $2,199 (kit), $3,499 to $5,599 (assembled)
Base Configuration: 5MHz 8085 and 5MHz 8088 CPUs, CP/M-85, five S-100 slots, 128K RAM (768K max), two 5.25-inch floppy disk drives, integral 12-inch monochrome CRT display (All-In-One), integral keyboard/keypad, two RS-232C and one parallel port, user manual
Video: 24-line x 80-column text, 640 x 225 graphics
Size/Weight: 13.5 x 19.5 x 19.5 inches, 50 lbs. (All-In-One)/7.25 x 19 x 19.25 inches, 40 lbs. (Low Profile)
Important Options: ZDOS, 8-inch floppy disk drive, 5MB or 11MB hard disk drive, RGB CRT display (All-In-One), monochrome ZVM-121 or color ZVM-134 monitor (Low Profile), ZBASIC, Z-25 or Z-125 printer

Zenith Z-148 (desktop PC)
Base Configuration: 8MHz 8088 CPU, MS-DOS 2.11 and 1.25, 128K RAM (640K max), 5.25-inch floppy disk drive, RGB and composite video ports, keyboard/keypad, RS-232C and parallel ports
Video: 640 x 200 graphics
Size/Weight: 16 x 4.8 x 16.1 inches, 22.5 lbs.
Important Options: one-slot daughtercard, expansion box, second 5.25-inch floppy disk drive, Z-125 printer

Zenith Z-150 (Feb. 1984, desktop PC)
Original Retail Price: $2,699 to $4,799
Base Configuration: 8088 CPU, MS-DOS 2.11 and 1.25, four ISA slots, 128K RAM (640K max), 5.25-inch floppy disk drive, RGB and composite video ports, keyboard/keypad, two RS-232 and one parallel port
Video: 640 x 200 graphics
Size/Weight: 16 x 6.25 x 16.5 inches, 42 lbs.
Important Options: second 5.25-inch floppy disk drive, 10.6MB hard disk drive, Z-125 printer

Zenith Z-158 (desktop PC)
Base Configuration: 8MHz 8088 CPU, four ISA slots, 128K RAM (640K max), 5.25-inch floppy disk drive, RGB and composite video ports, keyboard/keypad, RS-232 and parallel ports
Video: 640 x 200 graphics
Size/Weight: 16 x 6.5 x 16.5 inches, 42 lbs.
Important Options: second 5.25-inch floppy disk drive, 10.6MB hard disk drive, Z-125 printer

Zenith Z-200 (1985, desktop PC)
Original Retail Price: $3,999 to $5,599
Base Configuration: 80286 CPU, MS-DOS 3.1, six ISA slots, 512K RAM, 64K ROM, 5.25-inch floppy disk drive, RGB and composite video ports, keyboard/keypad, RS-232C and parallel ports
Video: CGA
Size/Weight: 21 x 16.5 x 6.5, 38 lbs.
Important Options: Xenix, one-slot daughtercard, expansion box, 20MB hard disk drive

Zenith Z-138 (transportable PC)
Base Configuration: 8MHz 8088 CPU, MS-DOS 2.11 and 1.25, ISA slot, 256K RAM (640K max), 5.25-inch floppy disk drive, RGB and composite video ports, integral 7-inch monochrome CRT, keyboard/keypad, two RS-232C and on parallel port
Video: 25-line x 80-column text
Size/Weight: 8.5 x 18 x 17 inches, 24.2 lbs.
Important Options: Z-125 printer, carrying case

Zenith Z-160 (Feb. 1984, transportable PC)
Original Retail Price: $2,799 to $3,199
Base Configuration: 8088 CPU, MS-DOS, four ISA slots, 320K RAM (640K max), 5.25-inch floppy disk drive, integral monochrome CRT, RGB and composite video ports, keyboard/keypad, RS-232 and parallel ports
Video: 25-line x 80-column text
Size/Weight: 19.5 x 8.38 x 19.13 inches, 38.6 lbs.
Important Options: second 5.25-inch floppy disk drive, Z-25 or Z-125 printer

Zenith Z-171 (April 1985, transportable PC)
Original Retail Price: $2,699
Base Configuration: 4.77MHz 80C88 CPU, MS-DOS 2.11 and 1.25, 256K RAM (640K max), two 5.25-inch floppy disk drives, 10-inch monochrome LCD, keyboard, RS-232C and parallel ports, productivity software suite, AC adapter
Video: 25-line x 80-column text, 240 x 200 graphics
Size/Weight: 9.5 x 13 x 6.6 inches, 14.3 lbs.
Important Options: expansion chassis, video board with RGB port, carrying case, battery pack

Zenith Z-181 (1986, laptop PC)
Original Retail Price: $2,399
Base Configuration: 4.77MHz 80C88 CPU, MS-DOS 3.2, 640K RAM, 3.5-inch floppy disk drive, monochrome LCD, RGB and composite video ports, integral keyboard. serial and parallel ports, NiCad battery pack, AC adapter
Size/Weight: 11.8 lbs.
Important Options: external 5.25-inch floppy disk drive, BASIC, internal modem, bar-code reader