Will the "tohd" cheatcode create a read-only situation, as is the case with the CD-ROM, or will knoppix also be using the hard drive to cache files, or do periodic writes?

The reason I'm asking is that this sounds like a good solution for a silent PC, using a CF (compact flash) in an IDE adapter for the hard drive. If it is doing periodic writes to the device however, then a CF card shouldn't be used (CF cards have limited writes (between 100,000 - 1,000,000 per cell).