 Smith 's had begun selling audio and photographic equipment and calculators at the end of the 1970s , with a modest degree of success . In 1980 its marketing development manager , John Rowland , hit upon the idea of creating " Computer Know @-@ How " sections in major branches to sell computer books and magazines . Most of the items on display were imports from the United States but their relatively high cost reduced their attractiveness to the casual buyer . The commercial success and mass market potential of the ZX80 caught Rowland 's interest ; he approached Sinclair , saw a prototype ZX81 and agreed to market the machine through Smith 's on an exclusive basis for the first six months after launch . As Rowland put it , " what we 've done now is bring the computer @-@ orientated publications together with an actual computer , to create the Computer Know @-@ How section of the store " , alongside computer software and blank cassette tapes . The ZX81 would be sold in 112 stores around the UK and would serve as the centrepiece of the " Computer Know @-@ How " sections . 
