Holborn Computers was founded in 1979 by Hans Polak and Dick Gerdzen. Their goal was to supply dedicated computers, based on microprocessor technology, to specific groups of retail shops. The hardware was based on the Zilog Z80 family, complemented with Eprom memory for program storage, 8 inch floppy drives for data storage and a 12" green phosphor monitor. The multi-user operating system was developed in house (Holborn Operating System or HOS). To enable use by technically unskilled users, the application software was menu driven, and could be operated by means of a lightpen (the mouse was not yet invented at that time).
The first system that was brought to the market was system 9100. On the picture you can see the main housing containing 4 8"floppy drives with a monitor on top of it. The lightpen is also visible. Among the first users were opticians and jewelers. They could maintain their customer database and their inventory, they could do their financial administration, could print labels to attach to spectacles and jewelry etc. The first systems used Beehive monitor hardware, build in the stylish Holborn housing, This hardware was soon replaced by dedicated Holborn hardware . The 12" tube was bought from a US company. See hardware pictures.
Shortly after the introduction of system 9100, a smaller, more affordable system was introduced: system 7100. Basically it contained the same hardware and software, but was limited to only 2 terminals/users. The market for these dedicated systems was difficult. The potential customers were facing economically tough times. And at the same time standard operating systems for personal computers began to appear. One of the very promising operating systems being CPM from Digital Research. Holborn decided to design and produce a smaller system based on this operating system. The microprocessor board, together with the terminal board were build in the same housing as the former terminal for system 7100/9100.
This video shows a system 6100 in action.