Clenlo Advert - February 1982

As more adverts are added to the collection, the fun becomes discovering more and more obscure microcomputers that time forgot.

And this is defintely one such computer: the Clenlo Ace Multi-User System, from Clenlo Computing Systems of south-east London.

It's a multi-user system in the style at the time, which was to host an individual processor and memory board - which Clenlo called the DPC-180 and which was based on a Z80A - on an S-100 bus, with another Z80A CPU to manage everything.

A close-up of the advert which nicely shows the multi-user architecture in use at the time: multiple plug-in boards, each with their own CPU and memory, on an S-100 bus

Each user then shared systems resources like printers and hard disk, whilst connecting to "their" processor, which ran CP/M, over RS232 serial with a terminal of some sort, whilst the system itself ran DPC/OS multi-user operating system.

That terminal could even be a Commodore PET, which despite being a fully-functional micro in its own right was actually cheaper than many dedicated mainframe terminals^[1].

Hard disk storage, which could be up to 100MB, was managed via a disk controller from Morrow Designs, founded by George Morrow.

A basic two-user system retailed for £6,580 plus VAT, which is about £37,700 in 2026.