Digital Group
Digital Group Computer was an early computer kit company where you could buy it assembled or build it yourself. Building it yourself was a great way to learn about computers and Digital Group had very excellent documentation. The bus was design allow you to change CPUs (8080,Z80 and 6800) and all your perpherial would continue to function. A neat trick! However they had their own bus which wasn't S100 which meant you had to buy cards from them.