Information regarding system files SYS6/SYS and SYS7/SYS.

Using CMDFILE (supplied with LDOS) it is possible to extract
library commands from SYS6 and SYS7 as stand alone utilities.
Another use is to develop patches for library commands.  See
your LDOS manual for information regarding the use of CMDFILE.
To use PATCH to patch a library member of either SYS6 or SYS7,
you must know which file contains the member, and what the
overlay number is.  If the overlay number is 2A (hex), you
would enter L2A on a line by itself before entering the patch
information.  You must use X'addr'= style patches for patching
system files 6 and 7 as the position of the member will change
during patching.  It is NOT recommended you patch system files
unless you know exactly what you are doing!!

Here are the overlay numbers for all library commands in
LDOS 5.1.4 and LDOS 5.1.5 (model 1 only):

OV#  System File  Command  Information
---  -----------  -------  ------------------------------------
 11  SYS7/SYS     AUTO
 13  SYS7/SYS     CREATE
 14  SYS7/SYS     DEBUG
 15  SYS7/SYS     DATE     (Patch SYS7B/FIX needed for 5.1.5)
 16  SYS7/SYS     TIME     (Patch SYS7F/FIX needed for 5.1.5)
 17  SYS7/SYS     CLOCK
 18  SYS6/SYS     KILL     (Patch SYS6B/FIX needed for 5.1.5)
 19  SYS6/SYS     LIB
 1A  SYS7/SYS     TRACE
 1B  SYS7/SYS     VERIFY
 1E  SYS6/SYS     MEMORY
 21  SYS6/SYS     DIR      (Patch SYS6A/FIX needed for 5.1.5)
 22  SYS7/SYS     FREE     (Patch SYS7C/FIX needed for 5.1.5)
 31  SYS6/SYS     APPEND
 32  SYS6/SYS     COPY
 33  SYS7/SYS     BUILD
 41  SYS6/SYS     LIST
 51  SYS7/SYS     ATTRIB   (Patch SYS7A/FIX needed for 5.1.5)
 53  SYS6/SYS     RENAME
 61  SYS6/SYS     DEVICE
 62  SYS6/SYS     LINK
 63  SYS6/SYS     RESET
 64  SYS6/SYS     ROUTE
 65  SYS6/SYS     SET
 66  SYS6/SYS     FILTER
 71  SYS7/SYS     DUMP
 72  SYS7/SYS     PURGE    (Patch SYS7D/FIX needed for 5.1.5)
 81  SYS6/SYS     LOAD
 82  SYS6/SYS     RUN
 91  SYS6/SYS     DO
 A1  SYS7/SYS     SYSTEM   (Patch SYS7E/FIX needed for 5.1.5)
 A2  SYS6/SYS     SPOOL
 E1  SYS6/SYS     A!       Reserved - Unused command.
 E2  SYS7/SYS     B!       Reserved - Unused command.  Will be
                           used for UNKILL at a future time.
---  -----------  -------  ------------------------------------
     SYS1/SYS     BOOT     This command uses internal coding in
                           SYS1/SYS.
---  -----------  -------  ------------------------------------
(Note:  The comments regarding patches refers to those commands
which are changed during upgrade from 5.1.4 to 5.1.5 for the
model 1 version only.  The associated patch file is listed as a
reference for those who are interested.)

Other changes made during update from LDOS 5.1.4 to 5.1.5:

Filename:     Description of change:
------------  -------------------------------------------------
BACKUP/CMD    Correct date display during query.
              Correct DATE parameter to allow year to 1999.
              If SYS0/SYS is copied, set the SYSTEM flag in the
              directory.
CONV515/ASM   *** NEW ***   Source code to CONV515/CMD.
CONV515/CMD   *** New Program ***   Needed to convert LDOS
              version 5.1.4 disks to version 5.1.5 format.
FORMAT/CMD    Change DOS ID version byte to 53H.  Set DATE bit.
IFC5/CMD      Public released version only, correct for proper
              date display.
LEAPYEAR/ASM  *** NEW ***   Source code to LEAPYEAR/CMD.
LEAPYEAR/CMD  *** New Program ***   Needed for LDOS 5.1.5 to
              correct an error in the SYSTEM (UPDATE) code
              module.  Execute once after SYSTEM (UPDATE) and
              BEFORE you use SYSTEM (SYSGEN) to save the
              configuration.
SYS0/SYS      Correct date input and display routines.
              Make boot display show version as 5.1.5.
              Change version ID byte @ 403EH to 53H.
              Allow alternate config/bak file to be loaded
              instead of config/sys during boot.
SYS2/SYS      Do not check or create an ACCESS password.
SYS3/SYS      If DATE bit set, use extended date/time fields.
------------  -------------------------------------------------
Note:  Disks created by LDOS 5.1.5 are fully compatible with
LDOS 5.3.x (model 3) and LS-DOS 6.3.x operating systems.
---------------------------------------------------------------
