Date   : Fri, 15 Apr 1988 03:40:00 GMT
From   : eve.usc.edu!mlinar@oberon.usc.edu (Mitch Mlinar)
Subject: The Highuser Option in ZCPR33

In article <SAGE.10354880@LL.ARPA> SAGE@LL.ARPA writes:
>
>   The maximum user area displayed by SHOW.COM is not the highest one you
>can log into but the highest one you are allowed to reference.  SHOW does
>display on one of its screens whether or not the Z33 command processor will
>log into high user numbers.  Z33 (and Z34) is the only command processor
>that optionally allows user numbers above 15 to be logged into, and there is

Wrong, Jay.  QP/M (which you may not know about, although it has been around
since 1983) has always offered 31 user areas.  In fact, *all* of the programs
associated with it (QSTAT, QPIP, CD, DIR, MAKE, etc.) know about 32 user
areas.  

>considerable risk in doing so.  I implemented that feature as an
>intellectual challenge for experimenters who do not mind living on the edge. 
>I do not recommend logging into high user areas as a matter of course.
> 

Here, I agree with Jay.  I have found it *very* rare that anyone needs that
many user areas.  Clearly, you never would want it on a floppy (not enough
storage to make it worthwhile).  Furthermore, CP/M+ trashes files above user
number 15 (it only looks at users 0 to 15 to make the allocation bit map) if
given half a chance.

On a hard drive, if you seem to be exceeding the limit, you should look at
your hard drive setup.  You might consider breaking your hard drive up into
smaller logical drives which should give some breathing room.

Although QP/M has always supported 31 user areas, most of the public programs
which support du: have problems above user 15 (especially if they want to
be compatible with CP/M+).  I agree with Jay that it should be used with
some care.

-Mitch