Date   : Wed, 15 Dec 1982 17:37:00-PST (Wednesday)
From   : tekmdp!laurir.Tektronix@Rand-Relay
Subject: shortening CP/M files

To shorten a CP/M file and free its extra blocks, just zero the
unwanted disk indices in the FCB and do a CLOSE, then either RESET the
disk or do a warm boot to force recomputation of the free block vector.
  -- Andrew Klossner (laurir.tektronix@rand-relay)