)
Values for Digital Research operating system ID codes (full AX return value):
 ??41h	- DOS Plus 1.2
 1060h	- DOS Plus 2.0 or 2.1 (1988-03-09???)
	  (this was basically a Concurrent CP/M-86 with built-in DOS emulation
	   developed between 1983-1986)
 1060h	- DR DOS 3.31 (OEM) (1988-04-27???, 06/1988)
	- DR DOS 3.32 (OEM) (1988-08-17)
	- DR DOS 3.33 (OEM) (1988-09-01)
	- DR DOS 3.34 (OEM)
	- DR DOS 3.35 (OEM) (1988-10-21)
	  for example: at least an issue for "Prism System 232" (10/1988)
	  and a French issue existed.
 106?h	- DR DOS 3.40 BETA 1 (1988-11-11)
	- DR DOS 3.40
	  (This is the first issue for sure known to be ROMmable, although
	  DR DOS should have been ROMmable right from the start (1987).)
 1063h	- DR DOS 3.41 various OEM and retail releases (06/1989-07/1989)
	- DR DOS 3.41T
 1064h	- DR DOS 3.42
	  (It is not clear, if this issue was actually released, since Lineo
	  recently (fall 1999) released some historical kernels, and one of
	  them is sailing under the name DR DOS 5.0 "Leopard" BETA 1 and has
	  copyright strings from 1990, while it still identifies itself as
	  being DR DOS 3.41... Unfortunately the uploaded archive is broken,
	  hence it is not possible to find out easily. Maybe DR DOS 3.42 was
	  nothing more than this early "Leopard" BETA???)
 1065h	- DR DOS ??? (1990-02-01)
	- DR DOS 5.0 "Leopard" BETA 2 (1990-03-16),
	- DR DOS 5.0 "Leopard" BETA 2B
	  (This was the first issue to use the new IBMBIO.COM/IBMDOS.COM
	  names instead of DRBIOS.SYS/DRBDOS.SYS.)
	- DR DOS 5.0 "Leopard" BETA 3
	  (This issue still uses separate boot sectors for floppies and
	  harddisks. The boot sector OEM label is still "DIGITAL".)
	- DR DOS 5.0 release (06/1990, 08/1990)
	  (This issue has a combined boot sector for both, floppies and
	  harddisks. The boot sector OEM label has changed to "IBM  3.3".
	  DR DOS 5.0 was the first DOS to introduce high-load capabilities.)
 1066h	- DR DOS ??? (1990-08-09)
	- DR DOS 6.0 "Buxton" ALPHA (02/1991-03/1991)
 1067h	- DR DOS ??? (1991-03-15)
 106?h	- DR DOS 6.0 "Buxton" BETA 2 (??/1991)
 106?h	- DR DOS 6.0 "Buxton" BETA 3 (05/1991, 1991-06-27, 1991-06-28)
 1067h	- DR DOS 6.0 release (05/1991, 08/1991)
	- DR DOS 6.0 BDOS patch "PAT304" English (1991-11-29, XDIR /C: 9D8Ch)
	  fix for "\\" in cmdline by Quick Basic 4.5/MS PDS 7.1 on Lantastic 4.0
	- DR DOS 6.0 BDOS patch "PAT303" English (1991-12-03, XDIR /C: 66B0h)
	  This patch makes INT 21/AH=4Eh (Search First) compatible with MS-DOS
	  when the Volume Label attribute is set. Previously under DR DOS the
	  volume label was only searched for if bit 3 was the only bit set in
	  the attribute whereas MS-DOS searches for the volume label if bit 3
	  is set, irrespective of any other bits in the attribute.
	- DR DOS 6.0 BDOS patch "PAT306" English (1991-12-11, XDIR /C: 8DE5h)
	  This patch fixes a problem with OPTASM which would give error 8
	  if there were not enough handles available. This patch forces the
	  system to check for available handles before it opens a file.
	- DR DOS 6.0 BDOS patch "PAT312" English (1992-01-07, XDIR /C: A0C6h)
	  This patch fixes a problem with INT 21/AH=26h (create PSP) the
	  segment from which the PSP was copied was incorrect so the the PSP
	  was not filled correctly and did not contain the command tail.
	- DR DOS 6.0 BDOS patch "PAT314" English (1992-01-10, XDIR /C: C964h)
	  This patch modifies INT 21/AX=33xxh, the Ctrl Break handler to
	  support undocumented MS-DOS function INT 21/AX=3302h.
	- DR DOS 6.0 BIOS patch "PAT315" English (1992-01-10, XDIR /C: DBAAh)
	  This patch fixes a problem where, when booting from a Bernoulli
	  drive, any DEVICE= statement in CONFIG.SYS failed if it was placed
	  after the device driver RCD.SYS v7.x and DOSOAD.SYS v1.x
	- DR DOS 6.0 BDOS patch "PAT317" English (1992-01-27, XDIR /C: B701h)
	  This patch fixes a problem where attempting to close a changed file
	  on a write protected disk seems to work after the first retry.
	  This was caused because when the retry is attempted the file has been
	  marked as not changed, so the attempt to write to disk is not made.
	- DR DOS 6.0 BDOS patch "PAT321" English (1992-02-19, XDIR /C: 947Bh)
	  This patch fixes a problem where the error codes returned from
	  INT 25h and INT 26h for "drive not ready" and "write protect"
	  errors were incorrect.
	- DR DOS 6.0 BDOS patch "PAT323" English (1992-02-20, XDIR /C: E1B0h)
	  This patch fixes a problem where, if the first command entered after
	  booting the machine is a single character, any use of the command
	  line recall keys will only recall the first command.
	- DR DOS 6.0 ??? German (1992-02-21)
	- DR DOS 6.0 update (02/1992)
	- DR DOS 6.0 BDOS patch "PAT326" English (1992-03-05, XDIR /C: 8EF2h)
	  This is an optional patch to prevent DRDOS from padding the
	  environment of EXEPACKed applications or utilities.
	- DR DOS 6.0 ??? German (1992-03-27)
	- DR DOS 6.0 BDOS patch "PAT334" English (1992-03-27, XDIR /C: 2AFEh)
	  This patch fixes a problem where selecting (R)etry after hitting ^P
	  while the printer is offline caused the system to hang.
	- DR DOS 6.0 "Windows 3.1 update, April 1992" "dr6win" (03/1992,
	  1992-04-07). This public update only includes patches addressing
	  full Windows 3.1 compatiblity. There should have been a full
	  "business update" for registered users, shipping a little bit later.
	- DR DOS 6.0 ??? English (1992-04-07)
	- DR DOS 6.0 BDOS patch "pat354" English (1992-07-28, XDIR /C: 3398h)
	  This patch for Beame and Whiteside Networks: On opening a duplicate
	  file handle which describes a device, a device open call is made to
	  inform the device driver that a new file handle has been opened.
	  This patch is current and up to date as of 1992-11-10.
	- DR DOS 6.0 update (07/1992)
	- DR DOS 6.0 BDOS patch "PAT301" English (1992-10-28, XDIR /C: 959Bh)
	  This patch fixes a problem with apps that opens a file, with Share
	  loaded, but then cannot delete the file until the file is closed.
	  This causes "Money Manager" to fail.
	- DR DOS 6.0 update (11/1992)
	Note: There is no known method to distinguish these different kernels
	       at runtime, except for - maybe - checksumming the IBMBIO.COM/
	       IBMDOS.COM files.
	      The listed patches only address a single problem, while the
	       listed updates are full rebuilds, also including all previous
	       fixes.
 1070h	- multitasking "Vladivar" kernel architecture and introduction of
	  DOS-like structures (1991-07-26, 08/1991)
	- DR DOS ??? (1991-09-26)
	- DR PalmDOS "Merlin" BETA 1-2
	- DR PalmDOS "Merlin" BETA 3 (1992-06-23)
	- DR PalmDOS "Merlin" Evaluation Release (1992-08-25)
	- DR PalmDOS Release Candidates 1-2 (1992-08-26)
	- DR PalmDOS/NetWare PalmDOS 1.0 (06/1992-11/1992)
	  (DR PalmDOS was the first DR DOS re-incarnation that supported
	  a genuine CDS, but still pretended to be DOS 3.31. Much of the
	  former CP/M stuff was stripped out to reduce the code size to meet
	  early Palmtop PC requirements. It introduced the patented dynamic
	  idle detection method (by Roger Gross), a special issue of the
	  TASKMAX program switcher (MINIMAX) to support Personal Information
	  Modules (PIM) plug-in executables, supported Flash/ROM disk,
	  XIP "Execute in Place" applications, and came with PCMCIA Card
	  Services and Service Stack (SS) partially written by Ian Cullimore
	  (ex-Poquet Computer Corporation founder).
	- DR DOS "Panther" BETA 1 (1992-10-16)
	  (This issue already supported DPMS, had the "Vladivar" pre-emptive
	  multitasker, DPMS-SuperStor disk compression, Multiuser-security
	  (World/Group/Owner), and much improved multi-windowing ViewMAX/3 GUI
	  which looked alot more like Windows than GEM. It pretended to be
	  PC DOS 5. However, this issue was never released and later partially
	  merged into the Novell DOS 7 project (without Multiuser-security and
	  ViewMAX/3). In 1999, Caldera Thin Clients released ViewMAX/3 under
	  GPL, see http://www.gemworld.com.)
 1070h??? - DR DOS "StarTrek" (STDOS) (07/1992-05/1993)
	  (A never released, though reportedly fully functional result of
	  a Novell and Apple team-up utilizing the DR DOS "Vladivar" multi-
	  tasker to run Apple's Intel-port of MacOS 7.1 on an issue of DR DOS
	  "Panther", even emulating HFS and Mac resources on DOS FAT file-
	  systems.)
 1071h	- DR DOS ??? (1992-11-26)
	- DR DOS 6.0 "business update" "DRDOS493" English for
	  Windows for Workgroups 3.1 (1993-03-19)
	- DR DOS 6.0 patch "PATDR6" English (1993-03-19) for NetWare
	- DR DOS 6.0 patch "PAT394" English (1993-09-17)
	- Apparently also some issues of DR DOS "Panther"???
 1072h	- Novell DOS 7/PNW "Smirnoff" BETA 1 (??/1993, probably 1993-04-26)
	- Novell DOS 7 "Panther" BETA 2 (08/1993)
	  (This "Panther" issue is much different from the early 10/1992
	  "Panther" BETA 1.)
	- Novell DOS 7 "Panther/Smirnoff" BETA 2 (08/1993)
	- Novell DOS 7 "Panther/Smirnoff" BETA 3 (09/1993)
	  (This issue does not have workarounds for Windows 3.1 "AARD" code)
	- Novell DOS 7 "Panther/Smirnoff" BETA 4 (10/1993)
	- Novell DOS 7 code freeze 1993-12-03???)
	- Novell DOS 7 release (12/1993-04/1994)
	  (also known as NWDOS or ND7, sometimes erroneously called NDOS)
	- Novell DOS 7 German release (1994-02-22)
	  (This issue is known to have workarounds for Windows 3.1 "AARD" code)
	- Novell DOS 7 updates 1-3 (???/1994)
	- Novell DOS 7 update 4 (1994-05-31)
	- Novell DOS 7 updates 5-9 (???/1994)
	- Novell DOS 7 update 10 (12/1994)
	- Novell DOS 7 update 11 (01/1995)
	- Novell DOS 7 update 12 (04/1995)
	- Novell DOS 7 update 13 (05/1995)
	- Novell DOS 7 update 14 (08-09/1995)
	- Novell DOS 7 update 15 (12/1995)
	- Novell DOS 7 update 15.2 (01/1996)
	  Note: The Novell DOS 7 updates 4-15.2 are full rebuilds, not patched
	   binaries.
	- Caldera OpenDOS 7.01 BETA (02/1997)
	  (basically representing Novell DOS 7 update 10 with minor
	  changes here and there)
	- Caldera OpenDOS 7.01 (02-03/1997)
	- Caldera OpenDOS 7.01 M.R.S. (05/1997)
	  (release of the kernel source code)
	- Matthias Paul's enhanced OpenDOS 7.02 ALPHA 1-4 kernels (07-11/1997)
 1073h	- Caldera OpenDOS 7.02 BETA 1 (09/1997)
	  (incorporating most the Novell DOS 7 update 15.2 changes,
	  except for IBMBIO.COM changes, plus a few other enhancements)
	- Caldera OpenDOS 7.02 BETA 2 (11/1997)
	  (now also incorporating Matthias Paul's ALPHA 4 enhancements,
	  the Novell DOS update 15.2 IBMBIO.COM patches have been
	  re-implemented)
	- Caldera OpenDOS 7.02 BETA 2A (12/1997)
	  (now incorporating all Novell DOS 7 update 15.2 changes)
	- Caldera DR-OpenDOS 7.02 (1997-12-2x)
	  (now for the first time the product name is written with a hyphen!!!)
	- Caldera DR-DOS 7.02 internal build (02/1998)
	- Caldera DR-DOS 7.02 release (03/1998)
	- Caldera DR-DOS 7.02A release (06/1998)
	- DR-DOS 7.02 Update 1 (08/1998)
	- DR-DOS 7.02 Update 2 (09/1998)
	- Caldera (Thin Clients) DR-DOS 7.03 BETA (1998-12-03),
	  sometimes referred to as "DR-DOS 7.03 BETA 3"
	- Caldera (Thin Clients) DR-DOS 7.03 release (1998-12-24, 1999-01-06)
	- Lineo DR-DOS 7.03 release (1999-06-07, 1999-09-09)
	  (this issue has no functional changes compared to the 1999-01-06
	  issue of DR-DOS 7.03)
SeeAlso: #01580,#01579,#01581,#04023