The 16 bit computer generation peacefully "killed" the 8 bit computers.
Amstrad couldn't see this move and released the Amstrad Plus range which should have been 16 bit. (Or perhaps it should have another Z80 to get a 2x8 bit while keeping compatibility with the the old range .... why not ?)
On the other hand, Amstrad was still producing cheap 16 bit PC compatibles with pseudo EGA capacity (16 colours), so in this way it was actually a 16 bit producer.
16-bit machines:
See Amstrad PC for more information on Amstrad's ventures into the 16bit world.