Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uunet!odi!ed From: ed@odi.com (Ed Schwalenberg) Newsgroups: comp.windows.ms.programmer Subject: Re: DOS Extender + Win 3.0 Message-ID: <1990Nov25.171302.7680@odi.com> Date: 25 Nov 90 17:13:02 GMT References: Organization: Object Design, Inc. Lines: 32 In-Reply-To: kea@kasoft.UUCP's message of 20 Nov 90 21:51:58 GMT In article kea@kasoft.UUCP (Ken Anderson) writes: I am dealing with 2 clients who want to window-ize their applications. They both currently use Phar Lap's DOS extender and a suitable C compiler. You're getting confused about three similar but unrelated issues. Issue 1: DOS Extenders are for using protected mode facilities under DOS; DPMI is a spec for DOS Extenders to enable extended programs to cooperate in the use of PM facilities and memory when running under DOS multitasking systems like Windows. If your clients want their DOS apps to work using the DOS virtual machines provided by Windows, you need only wait until Phar Lap comes out with a version of their extender that interacts with DPMI as implemented in Windows 3.0. The Rational Systems expander used by 1-2-3 already does this. Issue 2: WINMEM32.DLL is for using 32-bit code and data segments in WinApps on 386 machines. None of the compiler vendors has yet provided support for this; you'll have to roll your own or wait until they do. If your clients want their programs to be WinApps, and they need the 32-bit model, you'll have to get into this. I haven't actually used this facility yet, so I won't offer any opinions on which 32-bit compiler to use. Issue 3: Do your clients actually need a 32-bit environment, or are they using the Phar Lap environment primarily to use >640K memory? If they need the 32-bit environment, you need to decide about the issues above. But if they're just using lots of memory, the ordinary Windows environment may be enough.