On 9/17/20 6:19 AM, Paul Koning via cctalk wrote: > CDC also supports "long blocks" in which the I/O for a single block is done > in pieces, so blocks can be read or written that are longer than what you > would think is the limit from the device limits. I'm not sure how long the > longest "long block" is.
When testing out mods to 1LT, the longest record that I ever successfully read and wrote was about half a reel at 556 bpi. Of course, the data was meaningless. This was on a Cyber 74 (6600) using a 657 drive as the target and a derivative of SCOPE 3.1.6 (Special Systems hack). Acoustically, the best tapes were the short-record "stranger" tapes. All sorts of interesting noise. I could tell from across the room when someone was running the tape section of the Navy audit tests for COBOL just by the sounds. --Chuck