Centiseconds was one of the ways time was measured on the BBC Micro. Your convenient options for accurately measuring the passage of time were vsyncs (50/sec), centiseconds (100/sec), microseconds (1,000,000/sec), or cycles (2,000,000/sec).
It's actually in the commented original disassembly and used in some of the original BBC documentation / writing. Which is how it ended up here - the article is a mix of things I wrote and things I asked an AI to write for me from the notes / findings from the archaeolgy.