RESBDOS3.SPR and BNKBDOS3.SPR have been replaced
with versions from the Jon Saxton disassembly with
fixes distribution.  The file called zpm3fix.txt
have been included and details the fixes.

ZPMLDR has also been updated with the version from
the Jon Saxton disassembly.  However, it has additionally
been updated to correct an issue that was preventing
RomWBW from booting under ZPMLDR.

ZPMLDR has a slightly modified version of the rdSeq
procedure (compared to CPMLDR).  It appears that this
causes deblocking to be bypassed on the initial disk
read of CPM3.SYS.  As a result, the entire disk sector
(512 bytes) is read starting at 0x0080.  This winds up
overlaying 0x180 bytes of the start of ZPMLDR.COM causing
it to fail catastrophically.

According to the documentation at the top of zpm3ldr.z80,
zpmldr is normally loaded from system tracks to address
0x0400.  In that scenario, the read of the entire sector
would not overlay the start of the application.  So, I
suspect this is why this (bug?) is not relevant to many
implementations.

The ZPM3LDR.REL file used here has been modified to
sync the rdSeq procedure back to the DIR CPMLDR version.
This seems to allow ZPMLDR to work with RomWBW now.

--WBW  4:22 PM 12/8/2021

Jose Luis reported that attempting to change to a different
DU by using a named directory was not working correctly.
It was working with the original ZPM3 distribution, but not
with the Jon Saxton patches.  Refer to the RomWBW Issue
https://github.com/wwarthen/RomWBW/issues/324.  I was able
to track down the issue and have applied an additional
patch to correct the Jon Saxton variant.

--WBW 8:46 PM 3/12/2023

jduraes reported an inconsistency between the key bindings for the
built-in ZPM3 command line editing vs the key functions documented
in ZPM3.TXT.  Refer to RomWBW Issue https://github.com/wwarthen/RomWBW/issues/533.

When Jon Saxton implemented a set of patches to ZPM3, he also updated
the command line history to function a bit more like one would typically
expect (see zpm3fix.txt).  Part of this change included swapping the
functions of ^W and ^X for WordStar compatibility:

Old	New	Function
^A	^A	one word left
^B	^B	to beginning/end of line
^C	^C	reboot if at start of line
^D	^D	right one char
^E	^E	get previous line
^F	^F	right one word
^G	^G	delete char at cursor
^H	^H	destructive backspace
^I	^I	(TAB) ignored here
^J	^J	(LF) exit editor
^K	^K	delete all to the right
^L	^L	ignored
^M	^M	(CR) exit editor
^N	^N	ignored
^O	^O	ignored
^P	^P	toggle printer echoing
^Q	^Q	toggle autoprompt (if enabled)
^R	^R	ignored
^S	^S	left one char
^T	^T	delete word at cursor
^U	^U	add line to history
^V	^V	clear line, delete from history
^W	^X	get next line from history
^X	^W	delete all to the left
^Y	^Y	clear line

--WBW 2:39 PM 4/13/2025