Derek Stewart has compiled a document from postings made by Nasta (Zeljko Nastasic) on QL Forum about the ZX8301 chip used in the QL. The ZX8301 is IC22 on the QL circuit board.
It’s available to download as DOC, ODT and PDF files in a single zip file from the Hardware Documents page on my website:
http://www.dilwyn.me.uk/docs/hardware/index.html
or from the backup site at