The Amstrad CPC computers, especially the first model CPC 464, were one of the most successful computers in Europe in the mid-1980s, with more than two million units sold. It was a competitor to the Commodore C64 and to the Sinclair ZX Spectrum, and despite its rather ordinary looks and some oddities like the 3-inch floppy disk format, it sold very well due to its reasonable price. Towards the end of the 1980s, the CPC, like other 8-bit computers, was becoming inreasingly outdated and was being replaced by 16-bit computers1 like the Commodore Amiga, Apple Macintosh and the IBM PC XT and AT. 1990 saw the end of production for these computers.
The CPC computers were introduced in 1984 with the CPC 464. In 1985, the CPC 664 and the CPC 6128 followed. They had a large fan base, and several computer magazines appeared solely for the CPC. In Germany, they were sold under the name Schneider CPC (a company that builds and sells TV sets and stereo systems).
All the CPCs had a Zilog Z80A processor running at 4 MHz, 64 KB RAM (128 KB for the CPC 6128), and were only sold with an Amstrad monitor, which also provided the power supply for the computer. Of the 64 KB RAM, about 42 KB were available for application programs. On the CPC 6128, the surplus 64 KB could be used as a RAM disk or to store data via 'bank switching'; it wasn't available directly, as computer and operating system could only address 64 KB.
All the CPCs had a fairly good keyboard and rather mediocre monitors, which were either monochrome green or in colour; the CPC itself could display at a maximum of 27 different colours. The 464 had a built-in tape recorder, and an external floppy drive was available. The 664 and the 6128 had internal floppy drives, and plugs for external tape recorders. They had a printer and a joystick port, and an expansion port, for which appliances were relatively rare, however2.
Without doubt, the main point of criticism was the uncommon floppy disk format of 3-inch with 160 KB storage capacity per side. This was an Hitachi-developed system and nearly only used by Amstrad3. To pardon Amstrad, it should be said that at that time, both formats were new and theoretically the 3-inch could have become the world's standard format (were it not for the Apple MacIntosh and the MSX home computers already using 3.5-inch). Nevertheless, the non-standard format made the 3-inch disks disproportionately expensive (given that there were only two companies producing 3-inch floppies - Amstrad and Maxell), and this was a real nuisance if you consider that Amstrad could easily have adopted Sony's 3.5-inch floppy format. Even today, the CPC's are known as 'the computers with the odd floppies'.
The CPC had the built-in AmDOS (Amstrad Operating System), and the CPC 664 and 6128 were also delivered with CP/M 2.2 and CP/M 3.0 (CP/M+), for more 'serious' computing. They also had a built-in BASIC interpreter Locomotive BASIC.
Regarding computer games, most of the titles originally written for the C64 were also available for the CPC, usually a bit later. Sometimes, one had to lower one's demands concerning speed, graphics or audio compared with the C64 version, but that had more to do with the way the games were ported to the CPC than with its performance.
Lots of the software for the CP/M operating system could also be used on the CPC, as CP/M on Z80-computers was in widespread semi-professional use at that time (the IBM PC was not heard of until 1981). Here, the 'problem' wasn't the need to port the software (which wasn't necessary), but simply the fact that most of the existing software wasn't available on the CPC's 3-inch disks, but more likely on 5.25-inch or even 8-inch disks. One of the major software titles explicitly sold for the CPC was Borland's Turbo Pascal, which made the CPC a good choice for programming students.
An astonishing number of websites are dedicated to CPC computers and the good old days of 8bit computing. Just consult your favourite search engine and have a look. There are numerous emulators for the CPC available, if you want to have the look and feel from way back when on today's computers.