Short answers, pulled from the story.
The ZX Spectrum was released on the 23rd of April 1982. This date marks the arrival of the computer in thousands of British households, fundamentally altering the trajectory of the nation's technology sector.
The ZX Spectrum was developed by Sinclair Research with chief engineer Richard Altwasser designing the ULA and industrial designer Rick Dickinson creating the case. The 48 kilobyte version was released at a price of £175, significantly undercutting competitors like the BBC Micro.
The ZX Spectrum featured 15 colors with attribute clash where all pixels within a character block shared one foreground and one background color. Developers created unique visual effects by designing games and programs to work within these specific limitations rather than trying to avoid them.
Most ZX Spectrum software was distributed on audio cassette tapes with data transfer speeds of up to 1500 baud. The machine also supported type-in program listings in magazines, 7-inch 33 rpm flexi disc records, and audio stream data broadcast via radio stations.
Sinclair Research sold their entire computer product range and the Sinclair brand name to Alan Sugar's Amstrad on the 7th of April 1986 for £5 million. This acquisition led to the release of three improved models including the Spectrum +2, the Spectrum +3, and the Spectrum +2A.