INT 21 - DR DOS 3.41+ - DETERMINE DOS TYPE/GET DR DOS VERSION                   
	AX = 4452h ("DR")
	CF set
Return: CF set if not DR DOS
	    AX = error code (see #01680 at AH=59h/BX=0000h)
	CF clear if DR DOS
	    AX = version code
	    AH = single-user/multiuser nature (see #01581)
		10h single-user
		    AL = operating system version ID (see #01580)
		14h multiuser
		    AL = operating system version ID (see #01579)
	    DX modified (refer to note below)
Notes:	the DR DOS version is stored in the environment variable VER
	use this function if looking for single-user capabilities, AX=4451h
	  if looking for multiuser; this call should never return multiuser
	  values
	in DR DOS 3.41-6.0, DX=AX on return; for Novell DOS 7, DH=AH but DL=00h
	  (reportedly, DH=00h when booting NWDOS7 from installation disks)
	Novell DOS 7 returns error code 0001h if SETVER x.255 is in effect for
	  the calling program, or SETVER /G x.255 is in effect
	although based on DR DOS, CCI Multiuser DOS 7.xx,
	  IMS Multiuser DOS 7.x, and IMS REAL/32 7.50+ do not support this call
	With OpenDOS 7.02 BETA 2 and DR-OpenDOS 7.02+, the install check
	  in most tools has been changed to run with both, AH=10h and AH=14h
	  to support possible future "client side" multiuser releases of
	  DR-DOS which may return 14h instead of 10h. Tools should also strip
	  off the CP/Net bit before checking the kernel version.
	  Often used version checks like >= 1070h are invalid, therefore,
	  hence the AH and AL must be checked seperately.
	In DR DOS 3.31-6.0, and DR PalmDOS, DX=AX on return.
	For Novell DOS 7 - DR DOS 7.03 the DX value returned by this function
	  is the same as the DX value returned by INT 21/AX=3306h, and
	  represents the DOS revision (bits 7-0, currently always DL=00h) and
	  the version flags (bits 15-8, with bit 12 = DOS in HMAsee High Memory Area, bit 11 = DOS
	  in ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs.) of the "patch_version" field in the PCM_HEADER structure in
	  the IBMDOS.COM file. The version flags, however, are updated at
	  runtime to reflect the actual system status, resulting, for example,
	  in DH=10h for DOS in HMAsee High Memory Area, and DH=0 when booting Novell DOS 7 from
	  installation disks.
	The operating system version ID represents the BDOS (Basic Disk
	  Operating System) kernel version (of the DRBDOS.SYS aka IBMDOS.COM
	  file), and the two nibbles can actually be read as CP/M(Control Program for Microcomputers) An early operating system for micros based on the 8-bit Intel 8080 CPU (and later the compatible 8085 and Zilog Z80 CPUs).  MSDOS version 1.0 was essentially a clone of CP/M for the Intel 8086. version
	  and sub-version, that is DR-DOS 7.03 (version code 1073h) is
	  actually CP/M-86One of the three operating systems offered by IBMInternational Busiuness Machines for its original PCIBM PC (the other two were MSDOS and the UCSD p-System).  It has since evolved into DR-DOS version 6 and Novell DOS 7. version 7.3.
	Due to lost original patch sources from the backups, Caldera OpenDOS
	  7.01 merely represented Novell DOS 7 Update 10 with minor changes.
	For Caldera DR-OpenDOS 7.02, all the Novell DOS 7 patches up to
	  including Update 15.2 have been re-incorporated into the system
	  from other sources, while the missing patches for IBMBIO.COM were
	  independently re-implemented by Matthias Paul in 07/1997-10/1997.
	Novell DOS 7 (since 1993-11-08), OpenDOS 7.01 and OpenDOS 7.02 BETA
	  IBMDOS.COM return error code 0001h if SETVER x.255 is in effect
	  for the calling program, or SETVER /G x.255 is in effect.
	Since Caldera DR-OpenDOS 7.02 the SHARE 2.05+ (1998-01-05) driver
	  uses INT 21/AX=65A2h as an *additional* BDOS version check: If the
	  "FUCASE char" function is functional on a DR-DOS BDOS kernel 72h+,
	  SHARE assumes it is running on an OpenDOS 7.02 BETA 1 (73h) kernel
	  (or later) even if the BDOS version returned by INT 21/AX=4452h would
	  indicate an earlier issue of the kernel. Some 3rd party drivers
	  (like HPFS_DOS.EXE) were hardwired to detect Novell DOS 7 only,
	  and so the kernel version had to be patched back on such systems
	  to allow such drivers to work properly. The BDOS version and DOS
	  revision are stored in PCM_HEADER of the IBMDOS.COM file, see
	  table XXXX below.
	However, this is no longer necessary with the introduction of the
	  DR-DOS 7.02+ IBMDOS.COM (since 1998-01-10) and SETVER 1.01+
	  (since 1998-01-12) because they allow to fake BDOS versions as well
	  as faking DOS versions. In /X mode, a set sub-version of y = 100..127
	  will be used as BDOS version instead (64h..7Fh), while the DOS
	  revision will be used to report the DOS sub-version instead. For
	  example, given a DOS revision of 0, SETVER 6.114 would be the proper
	  value to fake Novell DOS 7 (114=72h) on a DR-DOS 7.02+ system,
	  reporting a DOS version of "IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911." 6.00. Sub-versions 128..255 will
	  completely disable this BDOS version check, and report a DOS sub-
	  version of 0..127. This is to work around problems with possibly
	  hostile programs, that try to detect DR-DOS to not run on this OS.
	Additional version check for 1072h kernels: At API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. level, there
	  is no known way to distinguish Novell DOS 7 from OpenDOS 7.01,
	  however, an IBMBIO.COM/IBMDOS.COM file date since 1997 and the
	  existance of an environment variable %OS%=OPENDOS usually indicates
	  an OpenDOS system (but not the other way around; some OpenDOS
	  BETAs still used %OS%=NWDOS!).
	Additional version checks for 1073h kernels: A functional test of
	  INT 21/AX=65A2h (see above for SHARE) can be used to distinguish
	  OpenDOS 7.02 BETA 1 from the later (OpenDOS 7.02 BETA 2+ and)
	  DR-OpenDOS 7.02 and DR-DOS 7.02 releases, which are both the
	  same, except for the name change and minor bug fixes. Testing
	  for the INT 21/AX=6601h/BX=0000h bug can be used to differentiate the
	  original release of DR-DOS 7.02 from later 7.02 updates and
	  DR-DOS 7.03.
	The DR DOS version is stored in the environment variable VER.
SeeAlso: AX=4412h,AX=4451h,AX=4459h


(Table 01580)
Values for Digital Research operating system version ID:
 41h	DOS Plus 1.2
 60h	DOS Plus 2.0 or 2.1
 63h	DR DOS 3.41
 64h	DR DOS 3.42
 65h	DR DOS 5.0
 67h	DR DOS 6.0
 70h	PalmDOS
 71h	DR DOS 6.0 March 1993 "business update"
 72h	Novell DOS 7.0
 73h	OpenDOS 7.02
SeeAlso: #01579,#01581,#04088,#04023


(Table 04088)
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-86One of the three operating systems offered by IBMInternational Busiuness Machines for its original PCIBM PC (the other two were MSDOS and the UCSD p-System).  It has since evolved into DR-DOS version 6 and Novell DOS 7. with built-in DOS emulation
	   developed between 1983-1986)
 1060h	- DR DOS 3.31 (OEM(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor.) (1988-04-27???, 06/1988)
	- DR DOS 3.32 (OEM(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor.) (1988-08-17)
	- DR DOS 3.33 (OEM(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor.) (1988-09-01)
	- DR DOS 3.34 (OEM(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor.)
	- DR DOS 3.35 (OEM(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor.) (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(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor. 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(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor. 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(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor. label has changed to "IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911.  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 PSPsee Program Segment Prefix) the
	  segment from which the PSPsee Program Segment Prefix was copied was incorrect so the the PSPsee Program Segment Prefix
	  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 undocumentedInformation about a product which is not publicly available from the manufacturer, and must be determined by reverse-engineering (disassembly, trial-and-error, etc.).	 Undocumented information tends to change -- often dramatically -- between successive revisions of a product, since the manufacturer has no obligation to maintain compatibility in behavior which is not explicitly stated. MS-DOS function INT 21/AX=3302h.
	- DR DOS 6.0 BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. 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 ®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 CDSsee Current Directory Structure, but still pretended to be DOS 3.31. Much of the
	  former CP/M(Control Program for Microcomputers) An early operating system for micros based on the 8-bit Intel 8080 CPU (and later the compatible 8085 and Zilog Z80 CPUs).  MSDOS version 1.0 was essentially a clone of CP/M for the Intel 8086. stuff was stripped out to reduce the code size to meet
	  early Palmtop PCIBM 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(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. 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 DPMSsee DOS Protected-Mode Services, 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
	  PCIBM 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 FATsee File Allocation Table 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


Bitfields for CP/M(Control Program for Microcomputers) An early operating system for micros based on the 8-bit Intel 8080 CPU (and later the compatible 8085 and Zilog Z80 CPUs).  MSDOS version 1.0 was essentially a clone of CP/M for the Intel 8086. type indicator:
Bit(s)	Description	(Table 01581)
 7-4	CPU(Central Processing Unit) The microprocessor which executes programs on your computer. type
	0000 = 8080
	0001 = 8086
 3-0	OS type
	0000 = CP/M(Control Program for Microcomputers) An early operating system for micros based on the 8-bit Intel 8080 CPU (and later the compatible 8085 and Zilog Z80 CPUs).  MSDOS version 1.0 was essentially a clone of CP/M for the Intel 8086.
	0001 = MP/M
	0002 = CP/Net
	0004 = multiuser
Notes:	Usually 10h (single-user) or 14h (multi-user).
	While earlier releases of the system utilities performed a test for
	  a version code of (>)= (10)xxh, this was changed with
	  DR-OpenDOS 7.02+ (now taking a possible multi-user version into
	  account): Most utilities now test for AH being either 10h or 14h,
	  and a BDOS version >=xxh to allow them to properly run on possible
	  future multi-user releases of DR-DOS. Before doing this test, some
	  of them strip off the CP/Net bit.
SeeAlso: #01580