The Plus series were quite (but not 100%) compatible with the original CPC computers. The compatibility issues came mostly from:
* The new Amstrad ROMs, breaking ROM access to the floppy drive (can be easily fixed by using a [[Plus System Cartridge|Downgrade System cartridge]])
* The emulated [[8255|PPI ]] chip, making the keyboard unresponsive* The emulated [[CRTC]], breaking CPC demos
The Plus series incorporated a list of [[ASIC|new features]], like a cartridge port for instant program loading, DMA for the [[AY]] soundchip, enhanced hardware scrolling, programmable interrupts, 16 hardware zoomable sprites (not vectorized) with an independent palette of 15 colours, and a choice of 4096 colours all in a new, sleek case which mimicked the keyboard-computer design that was ''en vogue'' in the 16-bit market (ST, Amiga etc).