Sinclair C5 with Sinclair claiming that he had found "very big" levels of interest. Hoover were sufficiently persuaded to allow Sinclair to divert 10 of their employees to modify C5s for overseas export. The bid to sell the C5 abroad failed; the Dutch National Transport Service told Sinclair that the C5 was not suitable for Dutch roads without improvements to its braking system, the addition of more reflectors, and the inclusion of the High-Vis Mast as part of the basic package. Most of the other ten countries that Sinclair inquired of demanded similar changes. The C5's reputation received a further battering when
Sinclair Sovereign and information could only be taken from the memory onto the screen. Five keys were used for memory operations. The Sovereign used a Mostek MK50321N main integrated circuit, the same as the Sinclair Wrist Calculator and some variants of the Sinclair Cambridge. Clive Sinclair had assumed that people would prefer attractive illuminated LED displays to LCD displays, which incidentally also required more expensive CMOS chips. However, his calculators were designed with the assumption they would be turned off between calculations, which did not prove to be the case. Advertisements suggested that the batteries would last "about a year" under normal