Date: Thursday, 24 January 1985
From: Bridger Mitchell <bridger at rand-unix>
To:   Info-Cpm at amsaa
Subj: PUBlic filetype patch for CP/M 2.2 - official version

PUBPATCH is a CP/M 2.2 BDOS patch that implements the PUBlic file
attribute (bit 7 of 2nd character of a filename) and makes a file with
the PUBlic attribute assessible from any user number.  PUBlic files
allows a single copy of "associated files" -- libraries, databases,
overlays, swap files, etc -- to serve all user numbers.  They retain
their other attributes and may therefore be read/write as well as
read/only.

Complete documentation of PUBlic files appears in "CP/M 2.2 Goes
Public", by Bridger Mitchell and Derek McKay, Plu*Perfect Systems, Dr.
Dobb's Journal, Nov. 1984.  Limited documentation is included in the
preamble of PUBPATCH.ASM, and supporting files and installation are
described in PUBLIC.DOC.

Some earlier releases by others, available on some RCPM systems, that
attempt to implement a similar patch are reporting differing degrees
of success.  To cut through any confusion, I've sent Keith Petersen
the Plu*Perfect Systems release disk, and he's uploaded it to
SIMTEL20.  Keith has removed the earlier versions - only the
"official" versions of the files remain and are listed below.  Note
that some "unofficial" versions were also called "PUBPATCH.ASM".

The patch can be installed in Z80 systems running standard CP/M 2.2
using RELPUBLC.COM to relocate PUBPATCH.HXR (a hex-relocatable version
of PUBPATCH).  The squeezed source file is PUBPATCH.AQM.

SD.COM (with SD.DOC) are SuperDirectory extended to support display of
PUBlic files.  DISK7P.COM (with DISK7P.DOC) is the extended file-
maintenance utility DISK7.

The PUBLIC.COM and PUBLIC.AQM file is v 1.1.  It corrects a bug in the
published source v 1.0, which failed to set the PUBlic attribute bit
for very long files that overflowed the extent count into the S2
directory byte.

Restrictions, documented in LICENSE.NOT, are summarized here:

PUBPATCH.ASM, PUBLIC.ASM, and derivative files RELPUBLC.COM and
PUBPATCH.HXR, are copyrighted by Plu*Perfect Systems.  Permission is
granted for single-user, non-commercial use.  Use of these programs
for any commercial purpose requires advance written authorization from
Plu*Perfect Systems.  DISK7 is licensed for non-commercial use by
Frank Gaude.

The files are available from SIMTEL20 as:

Filename			Type	 Bytes	 CRC

Directory MICRO:<CPM.PUBPATCH>
-AUTHOR.PUB.1			ASCII	this announcement
DISK7P.COM.1			COM	  4480  EA11H
DISK7P.DOC.1			ASCII	  1150  55E0H
LICENSE.NOT.1			ASCII	   758  03E9H
PUBLIC.AQM.1			COM	  6016  F67FH
PUBLIC.COM.1			COM	  1152  4B74H
PUBLIC.DOC.1			ASCII	  1325  D131H
PUBPATCH.AQM.1			COM	  6784  9CE6H
PUBPATCH.HXR.1			ASCII	   728  0748H
RELPUBLC.COM.1			COM	 13056  E37FH
SD.COM.1			COM	  4096  6F9EH
SD.DOC.1			ASCII	   641  E900H

...and for those who want the whole package as an LBR file:

PUBPAT.LBR.1			COM	 40832  B44AH

----
--bridger mitchell
