Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: $Revision: 1.6.2.14 $; site siemens.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!siemens!jrv From: jrv@siemens.UUCP Newsgroups: net.micro.pc Subject: Re: MS-DOS Environment Size Message-ID: <23900005@siemens.UUCP> Date: Mon, 17-Feb-86 11:01:00 EST Article-I.D.: siemens.23900005 Posted: Mon Feb 17 11:01:00 1986 Date-Received: Wed, 19-Feb-86 00:53:56 EST References: <1107@decwrl.UUCP> Lines: 55 Nf-ID: #R:decwrl:-110700:siemens:23900005:000:1702 Nf-From: siemens!jrv Feb 17 11:01:00 1986 For anyone who has not updated to DOS 3.1 and has run out of environment space here is a patch to DOS 2.x COMMAND.COM which allows you to allocate more than the default 10 paragraphs. Run debug on command.com (It would be advisable to do this on a duplicate copy in case something goes wrong with the patch.): c:> debug command.com The allocation of memory for the operating systems copy of the environment is hard coded as: Assembly Code Hex Values xxxx:0ece MOV BX,000A BB 0A 00 xxxx:0ed1 MOV AH,48 B4 48 xxxx:0ed3 INT 21 CD 21 Search for this piece of code with the 's' command in debug: s 100 l 7fff bb 0a 00 b4 48 cd 21 There should only be one occurence of this sequence. In my version of PC-DOS 2.1 (?) it is located at offset 'ece' in the file. To allocate a larger environment space change the value which is loaded into the 'bx' register using the 'e' command: e ecf 20 The example here would allocate 20 hex paragraphs to the environment. Complete the patch by writing the modified COMMAND.COM with the 'w' command: w (No parameters are needed with the 'w' if these are the only operations which you did while in debug.) DOS 3.1 Several months ago I also went through this process on DOS 3.1 because my manual does not have anything I could find about switches to expand the environment!! I cursed Microsoft for not providing a mechanism (so I thought) to do this especially when I discovered that the size for the environment was no longer hard coded as it had been in MS-DOS 2.x. My curses now are redirected toward IBM for not documenting the feature in their manuals. Jim Vallino ihnp4!princeton!siemens!jrv