Zenith Data Systems Advert - October 1982

Zenith Data Systems - the company formed after Zenith Radio Corporation had bought the Heath company from Schlumberger in early 1980 - is back with a couple of "16-bit" micros - the Z-120 and the Z-110.

Both are multiprocessor in the sense at the time, which meant having two different CPUs - an Intel 8088, the hobbled version of the 8086 as used in the IBM PC, and an Intel 8085, the 5-volt version of the earlier 8080 and which was introduced in 1976.

The 8088 wasn't quite a true 16-bit CPU as it only provided an 8-bit data bus. This made it cheaper to build around, and in this case made it much simpler to support the addition of the 8-bit 8085, as both could share the same support chips. However, with two fetches required to read every 16 bit chunk of memory, it was slower.

Also launched in the 1970s was the S-100, formerly Altair, bus, with both of these micros offering five slots on an S-100 bus for expansion.

And to complete the 1970s throwback references, the machines also ran CP/M-85 or CP/M-86, although Zenith's own not-fully-compatible version of MS-DOS - Z-DOS - was also available.

Both systems could also be turned into multi-user computers, with the provision of up to ten RS232 serial ports, although running so many users on a single CPU is a bit of a stretch.

The Z-120 came as an all-in-one unit, housing keyboard, monitor and disk drives, whilst the Z-100 was a "low profile" unit, where the monitor was an optional extra.

Both supported quite a high resolution of 640x500 pixels