Legacy apps in Windows/OS X was Re: Old MS-DOS & Win Software - test-drb@ccmp.vtda.org

7 Dec 2005

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Subject: Re: Legacy apps in Windows/OS X was Re: Old MS-DOS & Win Software
   From: "Chuck Guzis" <cclist at sydex.com>
   Date: Wed, 07 Dec 2005 18:32:54 -0800
     To: cctalk at classiccmp.org

   Consider
on Windows XP that you can still run the following code:

 	mov	cl,9
 	mov	dx,offset HWMes
 	call	5
 	mov	cl,0
 	call	5 
Huh?  Do you mean this?

MOV  AH, 9
MOV  DX, HWMes
INT  21h
MOV  AH, 0
INT  21h 
Nope, I mean what I said--try it.  This little tidbit goes all the way back
to the time before DOS 1.0, when some level of compatibility with CP/M
applications was implemented.  Notice that I didn't say "CP/M-86", which
uses int 224 to make system calls (which will not work under MS-DOS or
Windows of any flavor).  I suspect this is an artifact of old SC-DOS/QDOS. 
And it works on W98 too.  I know for a fact that old DOS DBASEII used it 
along with FCB support (another CP/Mism) with one caveat, the target drive 
or partition have to be less tha 500mb!  I know because I was running
a job costing system in DBASEII on a PIII running W98se and that was 
the trick. 

Allison