Advance Components Ltd.
Advance Components Ltd. was started in the 1930's in his chicken shed by A W Stapleton. The company started manufacturing RF sub-assemblies for radio equipment and then moved into the manufacture of test equipment. Advance Components went public in 1956, and was renamed Advance Electronics in 1964.
By the beginning of the 1970's the company had grown to over 1000 employees and was selling a wide range of electronic components, sub-assemblies and test equipment around the world.
For a few years in the 1970's Advance Electronics produced pocket calculators. These were manufactured in Bishop's Stortford from 1973 to 1975, and accounted for almost 20% of sales (about £1m) at its peak. At the beginning of this period they were one of the very few manufacturers, but the market quickly became crowded, at which point the calculator production line was abruptly switched to making power supplies for photocopiers.
The company has been bought and sold several times and is still in business making Uninterruptable Power Supplies and power conditioners. The company is currently based in Wrexham.
Some of the models were produced as self-assembly kits, and some were manufactured and labelled for Phytron Electronics and Fi-Cord.
Source : calculator.org