Zilog Advert - January 1981

It sometimes seems odd that CPU manufacturers were building their own micros, but there was precedent, with MOS Technology having to introduce the KIM-1 single-board computer in order to demonstrate its new chip.

Zilog too had previously released its filing-cabinet-sized MCZ computers back in 1979, but it's back again a slightly-more desktop-friendly range of micros, once again based upon its Z80 processor.

The advert mentions that the Z80 was used in 85% of all micros, which was not implausible if based on models.

The Z80's arch-rival, MOS Technology's 6502, might have been used in fewer distinct micros, but it did feature in many of the biggest sellers, including the Commodore PET, VIC-20, Apple II, Atari VCS/2600 and the Nintendo Famicom, and later on the Commodore 64, a machine which sold up to 17 million units.

However, the Z80 appeared in hundreds of different micros aimed at business users, was well as several big-selling home computers like Sinclair's ZX series, with new Z80 micros seeming to pop up every month, although they often disappeared again a few months later.

Even in this collection, there are roughly twice as many adverts for machines featuring the Z80 as there are for the 6502.

Despite that, the VIC-20, which shifted around 2.5 million units in its lifetime, probably sold more than most of the Z80 business machines combined, by itself.

But there is one thing that the 6502 definitely did do: when launched it was by far the cheapest CPU on the market, and its presence caused a price drop amongst its competitors, properly kicking off the small and home computer revolution.

There's not a huge amount of information about Zilog's micro in the advert, other than it ran, not suprisingly, a Z80, and had a choice of operating systems: Zilog's own RIO, and regular CP/M.

A basic system, with twin floppy disks, a printer and a VDU/terminal, retailed for £3,500 plus VAT, which is about £22,200 in 2026.