Date   : Mon, 06 Aug 1990 13:44:58 PDT
From   : Bridger Mitchell <bridger%monty@rand.org>
Subject: zcpr 3.3 questions

Dan,

In general, a number of the problems you are running into in
installing ZCPR 3.3have been solved or superceded by the current
Z-System version (3.4) and associated tools and relocatable libraries.
If you check with one of these Z-Nodes you will find a wealth of
current info.

213-670-9465   (Ladera Heights, CA)
617-965-7259   (Newton Centre MA, password ='DDT')

The most extensive documentation and notes on the Z-System are to be
found in issues of The Computer Journal and in specific directories on
the Z-Node remote CP/M systems.  I don't have specific references
at hand.

The extended environment includes addresses of the ZCPR, BDOS and
BIOS; it is described in columns by both Jay Sage and myself some
issues back.  In a zcpr 3.4 compatible system those addresses would
either already be assembled into the ENV segment, or they would be
installed when the dynamic Z-System is loaded/booted.  Also, the
JetLDR tool which comes with NZCOM and Z3PLUS automatically converts
an older external environment into an extended one whenever it is used
to load a system segment.


It is possible to ERA, REN, PROT, and MOVE directory entries with
direct BIOS writes.  However, this approach should be avoided in any
general-purpose tool, and certainly in a (resident) command processor.
The reason is that the host system might well mount another type of
file system, such as DosDisk (which allows one to use MS-DOS disks
transparently on a CP/M system).  In that case, an ERA command would
likely damage some crucual part of the dos disk.  There are also some
specific technicalities one needs to beware of, including multiple
directory extents.

-- bridger


End of INFO-CPM Digest V90 Issue #128
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