[TUHS] /dev/drum

Ronald Natalie ron at ronnatalie.com
Tue Apr 24 10:24:47 AEST 2018

It also makes no sense because disks of the day were constant angular density (unlike CDs for example, which are constant linear).    There’s no different in transfer rate anywhere on the disk.   Each track has the same number of sectors.
We spent a lot of time in those days with “elevator” algorithms and clustering inodes to try to minimize seek time.   The other thing that was done on the fancier devices (not often found on PDP-11s) was optimizing where you were in the rotational angle.    

The original UNIX filesystems were dumb.    It was <boot block><superblock><inodes><datablocks>.     Wasn’t until later things like the Berkeley file systems that things started to get more clever in layout.

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