Date   : Sun, 31 Aug 1980103:29:00-MDT
From   : Frank J. Wancho <FJW@MIT-MC>
Subject: STAT in 2.2

Before I get beat about the head and shoulders about STAT's setting of
the individual file attributes in 2.2, let me correct myself now:
STAT indeed does set those parameters on the disk copy of the
directory entry itself.  (This is opposed to 1.4 STAT which only sets
the whole disk as R/O or R/W and only until the next boot.)  You must
(in either level) do a disk system reset (and reselect the saved
default if 2.2) if you change disks while your program is running, or
do a DIR in CCP, or the changed disk will be assumed to be R/O!

This was particularly annoying with ED when I was creating the dummy
entries for the master cataloger programs, although I appreciate the
protective approach.

--Frank

P.S.  There is some confusion, still, about CP/M records (128 bytes
each), used by the read and write functions, and the SAVE built-in
command, which uses 256-byte pages, and the actual disk I/O.  For
example, my N* double-density system uses 512-byte blocks.  Does this
mean that for each disk access, my BDOS and disk controller interface
selects which CP/M record I want out of the four records in the
512-byte block, reading or writing 512-byte blocks for each disk
access regardless of what may already be in the buffer from the last
request?  Can anybody explain what is really going on here?