The PC Engine is a 8-16 bits console which had quite a great success in Japan from 1986, roughly, until early 90's.
Although this console is pretty old, it already featured a cd drive. And what a cd drive: Even if only x1 speed, this extension was enabling ADPCM sound (for hi quality digitized sound/speech), cd sound, obviously, and very hi capacity for games, allowing anime sequences and even digitized video at the end (Huvideo, very impressive).
The raw console was amazing and was featuring 6 PCM voices, with an instrument of 32 samples of 5 bits for each, a 8-16 bits processor called Hu6280, which is a boosted 6502 with 16 bits shortcuts for video registers and extra addressing modes. It had also an addressable size of 64 kb among which could be fitted 8 bank of 8 kb each. A whole bank were devoted for RAM (which was 8 kb).
Concerning the video, it was handled by a pure 16 bits processor with 32 kb of RAM. Able to handle directly 64 sprites on two planes and a 8x8 pixels tiles plane, and in that period it was perfect for creating hi speed shoot'em ups (the predilection domain of the pc engine). Furthermore, it could handle 16 palettes of 16 colors for sprites and another 16 palettes of 16 colors for tiles. Each color could be chosen among a 512 color palette (3 bits for Red, 3 bits for Blue and 3 bits for Green).