Cork City & County Archives has uploaded a catalogue containing detailed descriptions of the archives and manuscripts available for research in the Reading Room at the Seamus Murphy Building, 33a Great William O'Brien Street, Cork. (Some collections have access restrictions.)
Where an online digital copy of a document is available, there is a link from the description. There are also links to full descriptive lists about each collection in pdf format for download.
The landing page explains that the catalogue is a work in progress.
You can search the catalogue here.