DR-DOS 8 may be the last.
co-founder and CEO of DeviceLogics. 
In fact, said Sparks, "This is probably the last major
upgrade we'll do to DR-DOS. We recognize the technology is well-past its
prime."  http://www.microsoft-watch.com/article2/0,4248,1558008,00.asp?kc=MWRSS02129TX1K0000535


http://archives.seul.org/independence-l/Aug-1999/msg00178.html
The little trick to doubble graphic performance (use FastVid or CTPPro on a
Pentium Pro, Celeron, or later architectures.  This enables CPU features that
are disabled by default, and this can better-than quardruple performance (20
MB to 90MB).  Read appropriate warnings.)
http://www20.tomshardware.com/motherboard/19970123/

http://www.generation.net/~hleboeuf/dos7comm.htm links to
http://home7.inet.tele.dk/batfiles/msdos7/ which indicates that the URL to
bookmark for that site is <A HREF="http://purl.oclc.org/net/msdos7/">http://purl.oclc.org/net/msdos7/</A>.


STACKS
http://support.microsoft.com/default.aspx?scid=kb;EN-US;84300

<H3>Ranges for n and m in STACKS=n,m</H3><UL><LI>MS-DOS 3.1 and earlier have no support for swapping of stacks
</LI><LI>MS-DOS 3.2 and later support values in range N=8-64, M=32-512
</LI><LI>MS-DOS 3.3 added support for 0,0, which is equivalent to behavior
in 3.1 and earlier.
</LI></UL><H3>Default Values for STACKS</H3><UL><LI>MS-DOS versions earlier than 3.2 do not support STACKS; behavior
   is equivalent to STACKS=0,0 on MS-DOS 3.3 and later.
</LI><LI>MS-DOS 3.2 always defaults to STACKS=9,128.
</LI><LI>MS-DOS 3.3 and later use special case codes that check for PC,
   PC XT, and PC Convertible. If any of these is detected, STACKS
   defaults to 0,0. Otherwise, STACKS defaults to 9,128.
(Note: Windows Me <A HREF="http://support.microsoft.com/?kbid=274646">always</A> uses STACKS=0,0)

<H3>Error Messages</H3>

If stack switching is enabled and MS-DOS runs out of free stacks, the
following message will be displayed:
<BR /><div class="errormsg">
   FATAL : Internal Stack Failure, System Halted.
</div>
If the above message is displayed, try a higher number for n in
STACKS=n,m. If you experience random hangs or other strange behavior,
try increasing the m value in STACKS=n,m.



ScanDisk's creates DIR000? directories
(where the ? is replaced by an integer) when ScanDisk finds directory
structures that are damaged beyond repair.  Files in those directories are
Read-Only and Hidden, and MS-DOS 6.22
<A HREF="http://support.microsoft.com/?kbid=126572">&quot;</A>MS-DOS ATTRIB command does not change the attributes on these files.<A HREF="http://support.microsoft.com/?kbid=126572">&quot;</A>
The MS-DOS 6.22 <A HREF="http://support.microsoft.com/?kbid=126572">&quot;</A>DELTREE command does not remove directories named DIR000<x> where x is an integer number. For example, the DELTREE command does not remove a directory called DIR0001.<A HREF="http://support.microsoft.com/?kbid=126572">&quot;</A>


<A HREF="http://support.microsoft.com/?kbid=78557">EMM36 history and troubleshooting</A>
<PRE class="in_text">
MS-DOS 5.0                    4.20
MS-DOS 5.00a                  4.33
MS-DOS 6.0                    4.45
MS-DOS 6.2                    4.48
MS-DOS 6.21                   4.48
MS-DOS 6.22                   4.49
Windows 3.1                   4.44
Windows 3.11                  4.44
Windows for Workgroups 3.1    4.44
Windows for Workgroups 3.11   4.48
Windows 95                    4.95
Windows 98                    4.95
                                </PRE>