Short answers, pulled from the story.
The Amstrad CPC series sold approximately three million units during its production lifetime from 1984 to 1990. The CPC 464 alone accounted for more than two million of those sales, making it one of the most successful home computers in Europe.
CPC stands for Colour Personal Computer. Amstrad produced the series between 1984 and 1990 as a range of 8-bit home computers.
All Amstrad CPC models used the Zilog Z80A processor, clocked at 4 MHz. Due to memory access constraints designed to prevent video corruption, Amstrad estimated the effective clock rate at approximately 3.3 MHz.
The CPC 472 was created by Amstrad's Spanish distributor Indescomp to circumvent a 1985 Spanish import tax of 15,000 pesetas on computers with 64 KB of RAM or less. It added a non-functional 8 KB memory chip to push the stated total to 72 KB, clearing the tax threshold. Once Spain joined the European Communities under the Treaty of Accession 1985 and the tax was removed, the 472 was discontinued.
The plus range launched in 1990 as a hardware refresh of the CPC platform, adding 16 hardware sprites, soft scrolling, a 4096-colour palette, and a DMA sound engine. It included the 464 plus, 6128 plus, and the GX4000 game console. Despite the upgrades, it was built on an 8-bit CPU at a time when buyers were moving to systems like the Amiga and the Mega Drive, and it was a commercial failure discontinued shortly after launch.
Roland was a mascot created for games published by Amstrad's in-house software label Amsoft. The character was named after Roland Perry, one of the lead designers of the original CPC range. Because the games were not designed around a consistent character, Roland's appearance varied widely across titles, from a spiky-haired blonde teenager to a white cube with legs.
The KC compact was a clone of the Amstrad CPC built by East Germany's VEB Mikroelektronik Mühlhausen in October 1989. It ran a customised version of the CPC 6128 firmware and was largely compatible with CPC software. It was the last 8-bit computer introduced in East Germany, and only a very small number were sold before German reunification.