Application-Specific Integrated Circuit (ASIC)
An ASIC is an especially manufactured custom Chip designed to fulfill special fonctions.
The main reason is to perform special tasks or combine different electronic componnents into a single Integrated Circuit (Chip).
Amstrad Custom chips
The Amstrad CPC used one custom chip : the CRTC (or VGA ? don't remember well..)
Latter CPC series included a "pre-ASIC".
The Amstrad Plus include a "second heart" simply referred as the ASIC.
The Amstrad Plus ASIC perform many additionnal features that the old CPC series couldn't : the "Plus Features".
- Hardware Sprites.
- CRTC emulation.
- Hardware Scrollings.
- Maybe some interactions with the ACID chip in Cartridges.
- DMA sound channels.
- Many many more.