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 video Gate Array (also called VGA...but nothing to share with the Video PC standard...)
Latter CPC series included a "pre-ASIC" to merge the VGA and the CRTC.
The Amstrad Plus include a "second heart" simply referred as the ASIC.
This 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.