Middle Age...
The NASCOM-2 appears to have been under development for quite some time before its release. This was the machine that Nascom pinned their hopes on. It was certainly far more powerfull than its predecessor.
The NAS-BUS was created to add expansion to the NASCOM family of computers. (Unfortunately, due to lack of board space, a separate buffer board had to be designed for the NASCOM-1.) The idea was, in view of the popularity of the NASCOM system, to produce a UK competitor to the S100 bus. The new bus would be simpler and cheaper to manufacture than the S100 system - and wouldn't need any licensing agreements!
Unfortunately the company was doing too well. They funded the NASCOM-2 without external finance but were immediately beset with component sourcing difficulties. The scarcity of the new 4118 (2kBx8) RAM chips was so severe that Nascom provided a 16k dynamic RAM board with every NASCOM-2 sold instead of fitting the 8k of static RAM which had been intended.
The expected return on the new NASCOM-2 computer failed to materialise in time. Their main City backer decided not to allow further working capital.