DOS/32 Advanced DOS Extender - FAQ


Question #1:
What is DOS/32 Advanced DOS Extender?

Answer #1:
DOS Extender is a 32-bit, high-performance, high-speed protected mode Run-Time program that allows 32-bit DOS applications to run in a 32-bit flat protected mode environment. Due to the limitations placed by the standard real mode DOS, such as 64KB segments and 1MB top memory barrier, the programmers and application software developers seek an extensions and tools that fully allow them to exploit the features and capabilities found in the modern computers. DOS/32 Advanced DOS Extender is such a tool.

When designing and programming DOS/32 Advanced DOS Extender, we felt that the most important goals that were to be reached and requirements to be met, were the Speed, Compatibility and Flexibility. Today, DOS/32 Advanced DOS Extender is the fastest commercial DOS Extender available on the market, featuring incredible flexibility through numerous configuration options and being fully compatible with such industry standards as DOS/4GW DOS Extender by Tenberry Software and WATCOM C/C++ development package. Breaking the 1MB real mode DOS barrier, DOS/32 Advanced DOS Extender allows you to manage up to 2GB of physical memory. 32-bit protected mode applications can exploit all the features found in the most recent processors. And of course compatibility with older software ensures that a large software database can be used without requiring any changes to be done, just Plug and Play. All in all, DOS/32 Advanced DOS Extender is a fast and solid solution for protected mode programmers, application software developers and high end users looking for a way to discover the true power buried in their computers.

Question #2:
What features are available in DOS/32 Advanced DOS Extender?

Answer #2:
DOS/32 Advanced DOS Extender features a very fast protected mode Kernel, based on DPMI (DOS Protected Mode Interface) specification version 0.9, which provides applications with DPMI subset and supports well over 60 different functions. DOS/32 Advanced is the number one DOS Extender when it comes to fast mode translation operation and interrupt processing, the essential factors that directly affect the speed of your protected mode programs. DOS/32 Advanced extends over 60 DOS interrupts allowing the 32-bit applications to directly issue commands to for example read and write disk drive without worrying about real mode DOS limitations. In addition, DOS/32 Advanced has a built-in support to extend such features as Windows® 95/98 Long File Names and VESA VBE 2.0 functions. Finally, DOS/32 Advanced DOS Extender takes only as little as 28KB of disk space and can run on computers with only 640KB memory available, making it an excellent candidate for running embedded systems on low end machines, even though it has been designed to take advantage of the latest Pentium(TM) technology.

Question #3:
Must I bind DOS/32 Advanced DOS Extender to my applications?

Answer #3:
DOS/32 Advanced DOS Extender can be bound to your 32-bit protected mode applications, making it possible to have the DOS Extender and the program to reside in one and the single file. DOS/32 Advanced can also be executed on a program, allowing you to run programs on CD-ROMs and other non-writeable devices. Additionally you can bind a specially designed stub file, less than 1KB in size, to your applications, effectively saving the disk space.

Question #4:
How much extended memory does DOS/32 Advanced require to maintain its full functionality?

Answer #4:
DOS/32 Advanced DOS Extender does not require any extended memory at all. In fact, the DOS Extender will function properly and be able to run your protected mode applications on computers with only 640KB base memory available.

Question #5:
Can I allocate more than 64MB of memory installed in my computer with DOS/32 Advanced?

Answer #5:
Yes, DOS/32 Advanced DOS Extender supports allocation of up to 2GB of memory when running under the XMS system software and up to 256MB when running under the VCPI system.

Question #6:
Does DOS/32 Advanced support 16-bit segments in a 32-bit protected mode application?

Answer #6:
Yes, it does. You can even have an entry point in a 16-bit protected mode code segment, and your application is not at all required to be 32-bit.

Question #7:
Does DOS/32 Advanced support auto passup of hardware interrupts in range IRQ 8..15?

Answer #7:
Yes. DOS/32 Advanced built-in DPMI server will automatically allocate a callback for an IRQ when you install a protected mode handler for that hardware interrupt. The hardware interrupts in range IRQ 0..7 and 8..15 are always automatically passed up to the protected mode if the respective protected mode handlers are installed. Additionally you can manually allocate and install real mode callbacks by using DPMI functions 0303h and 0201h, which are natively supported by the DOS Extender.

Question #8:
Can I debug protected mode programs which use DOS/32 Advanced DOS Extender with WATCOM debugger?

Answer #8:
Yes, you can. Simply specify the -tr=rsi option on the command line and debug the application as usual. Note that the debugger provided with WATCOM C/C++ is the default debugger for DOS/32 Advanced, because of the DOS Extender's excellent emulation of DOS/4GW DOS Extender.

Question #9:
Does DOS/32 Advanced support protected mode executable compression?

Answer #9:
Yes, DOS/32 Advanced DOS Extender supports compression of "LE"- and "LX"-style protected mode executables converting them into a custom Linear Compressed "LC" file format. The SUNSYS Compress Utility program, specially developed for this purpose is included with DOS/32 Advanced DOS Extender. Note that the "LC" compressed executables, once compressed, cannot be decompressed back to the original state, which provides you with a good protection against unwanted intrusion into your application's code.

Question #10:
Can I run programs that are bound other DOS Extenders, for example DOS/4GW Professional, under DOS/32 Advanced?

Answer #10:
As long as the program you intend to run is not compressed, DOS/32 Advanced will without problems be able to run it. However if a program is written to run under a particular DOS Extender (ie it uses special resources that are not available in other DOS Extenders), DOS/32 Advanced will most likely report an error.

Question #11:
I am getting these annoying warnings every time I run my program:
DOS/32A warning (9003): real mode interrupt vector had been modified: INT 00h
DOS/32A warning (9003): real mode interrupt vector had been modified: INT 22h
Can I disable them, and if yes, how?

Answer #11:
There are several ways to disable the warnings issued by the DOS Extender. One way is to add an option /QUIET to the DOS/32 Advanced environment variable DOS32A which is usually defined in your autoexec.bat file. This option will effectively disable all the warnings. Another option, /NOWARN:nnnn allows you to disable warning with a particular number, in this case 9003. Yet another way to disable warnings for only one application that uses DOS/32 Advanced DOS Extender is to use the SUNSYS Setup Utility program provided with the DOS Extender. Run the Setup Utility on the application you wish to reconfigure, press the F2-key, then 4-key and turn off the Report Modified Real Mode INTs option by pressing the ENTER key. Exit the Setup Utility program by selecting Apply Changes and Exit option (F10-key).


Copyright Supernar Systems, Ltd. 1996-2005
All Rights Reserved.