GRAPHICS: Comparing these computers we can say that the Commodore 64 has about the same graphic quality as the Amstrad CPC. This last one has 3 different text and graphical resolutions (20x25x16c - 40x25x4c - 85x25x2c / 160x200x16c - 320x200x4c and 640x200x2c), which makes it the machine with the higher graphic capability. Commodore 64, in the other hand, has 1 text resolution (40x24x16c) and 2 distinct graphic resolutions, which are 160x200 with 16 colors and 320x200 with 4 colors. At last, the ZX Spectrum presented only one screen resolution, used to present graphics and text simultaneously. Its resolution is 256x192 and 8 colors, plus another 8 with the "Bright" command.
Amstrad CPC and Commodore 64 could use at least 4 different colors per 4x4 pixel block, against the only 2 colors per 8x8 pixel block of the Spectrum, giving these two machines a general, but not very frequent, better look over Spectrum's graphics.
Spectrum's great disavantage was the 2 colour limit per each group of 8x8 pixels, which forced the game companies to work more to avoid color "collision problems". The result of the effort of trying to avoid the "contagious colour effect" in the Speccy games is, in most of the cases, a "piece of art".
Even with this big limitation, the ZX Spectrum games show a better care and attention to the graphics department. Commodore 64 and Amstrad CPC games show less detailed graphics and, in some times, a worse color attribution (not worse colors).
The Commodore 64 and Amstrad CPC game graphics normally use a different approach. In order to have 16 colors at once, they used the 160x200 resolution, which made them both graphically inferior to the real Spectrum resolution. Companies programmed bigger graphics (doubling the pixels size), which resulted in a visible loss of quality and definition. Even with the possibility of mixing colours without affeting the color of the nearby pixels, not always these two machines did show a better graphic quality than the classic ZX Spectrum. This is a reality! Just compare the graphics and the size of the pixels used in most of the games! Only in some some cases, Commodore 64 and Amstrad CPC game graphics are better than the ones presented in Sinclair's machine.
As an overall appreciation, ZX Spectrum has vivid colors as well as the other two machines, but in most of the cases the backgrounds are more detailed and the sprites less pixelated, overcoming Commodore and Amstrad strange "pixel zoom" technique.
SOUNDS: The sound/music quality in games is another interesting part. In this department, the ZX Spectrum 128K games are normally better than Amstrad CPC or Commodore 64, and very similar to Atari ST. Both the ZX Spectrum and Amstrad machines possessed a General Instruments AY-3-8912 sound chip, which allowed us to have brighter sounds and music with an unique and clear audition. Vibratos were always very good and digitised speech was excellent in some games. Although, ZX Spectrum games normally had better musics and sounds when compared with the same games produced for the Amstrad CPC. Probably a superior interest from the Software Houses over Sinclair's machine when developing their software. Unfortunately, the ZX Spectrum did not have a stereo output, which would give its sound chip a better performance and quality.
As we've told before, Amstrad CPC sound was very similar to the Spectrum, but not as good as it. Vibratos were not better, as well as the general quality of the instruments used.
In the other hand, Commodore 64 also had a very good sound chip (called SID - Sound Interface Device), capable of producing high quality sounds in its three channels. SID came with four types of sounds by default. To these base sounds it was possible to apply some filters in order to produce more sounds. This made several individuals and Software Houses to develop musics with double care and attention. Games for the Commodore 64 started to present better sounds and musical scores, which led this machine's sound chip to a very high platform. Many persons within the videogames market got famous for their excellent musics and a very large number of addicts arose from the SID "magical" chip.
CPU: Amstrad CPC CPU was a Z80A microprocessor, an improved version of Z80. Its clock speed was 4MHz, which was more than enough to make games run soft and fluid. Commodore 64's CPU worked only at approximatelly 1 MHz, but due to its internal memory capabilities, C64 could show very smooth screen scrollings, giving games a "boost" for a general better look. At last, ZX Spectrum came with a Ziglog Z80 CPU at 3.55 MHz, very similar to the CPC. Unlike Commodore 64, scrolls on the Spectrum were a little worse due to the machine's internal capabilities, and few were the ones who programmed this machine to make screen scrolls fast and smooth. However, ZX Spectrum games never had speed problems.
OVERALL: The overall tests certainly point out a winner, and you know it already! Even with its own limitations, the ZX Spectrum show better results than the other two computers. Many times better in graphics, most of the times better in sounds, Sinclair's ZX Spectrum is a classic for several reasons. Game companies worked seriously hard for this machine, trying to show us how good it was. They tried to overcome Speccy's limitations all the time, as if they never existed. It's a reality that game companies always worked harder for this computer, creating games with double care and attention. The result is clear. A magical sense of "better" is present while playing Speccy games. Not even Commodore 64 or Amstrad CPC could ever beat this classic. Shielded by the great devotion of their creators, games for ZX Spectrum show an eternal superiority.
Of course Commodore and Amstrad users will collide with this conclusion. And they will forever collide. Our machine is internally "better" than the others' machines. Our machine will forever be the best of all. The top of any others. And we do not discuss that. We have analysed these three "sweet" computers and tried to go through anything to find out the good and bad of them. We have looked at these machines with neutral eyes, heart and mind, so what results from our tests are ONLY our neutral and humble opinions. Your opinions may be different in some ways, naturally, but certainly we all agree with the core of this comparition.
