The Sinclair was a small, inexpensive computer consisting of a keyboard and CPU in one case. It came with 2K RAM expandable to 16K. It needed an external monitor for display. It was announced in 1982 and sold for $99.95. It was featured on the cover of "Popular Science" magazine in its August 1982 issue, with the heading "World's First $100 Personal Computer." A 16K RAM pack was available for $50. A printer and an auto-dial modem were available for $100 each.

The Sinclair was a very small computer, measuring less than 7 x 7 inches. It had no on-off switch, and came on when you plugged in the AC adaptor. Although it was priced low, the small keyboard made it difficult to use for long periods of time.