In June 1985, Amstrad took the initial design and, building upon the same idea, removed the tape recorder and replaced it with a disc drive, using the same hardware sold as the [[DDI-1]] add-on for 464 owners. The result: the CPC664. Sporting a less colourful and easier-to-type-on keyboard, the CPC664 appealed as a more serious machine and proved a success, especially due to its quite fast 3", 180KB/side drive.
Nethertheless the 664 did have a very short life and was soon replaced by the 6128 (according to [[Amstrad Action]], Issue 1, Oct 1985, page [[:File:Amstrad Action001 08.jpg|8]] the 664 was produced only from May until August 1985).
* ''[http://www.gondolin.org.uk/hchof/review.php?id=29&mcid=27 Your Computer (June 1985) review of the CPC664]''