The scroll vs codex issue is very much what I had to deal with when I started programming in the early 1970s. Data files on magnetic tape were "sequential access" files, one record after another; essentially a scroll. Data files on magnetic disk were "random access" files, there was a small file which was like a "contents page" at the beginning that would tell you where to go for a particular record and a big file for the data itself; essentially a codex or "book" (in the modern sense). Strangely, all the difficulty to do that work is "ancient history" - seemingly as ancient as the Dead Sea Scrolls or the Nag Hammadi Codices now!

Robert Meyer