Creepy DOS and BIOS functions (need help!!!)

I use Borland C++ Compiler 5.5,which runs in DOS, I just put bcc32 and the source code (the .cpp file that has source code) and it compiles it. Well I am having the following problem while trying to call a DOS function. Here is my program:

Code:

---

#include <stdio.h>
#include <dos.h>

void main()
{
int major,minor;
union REGS regs; //required for making DOS calls

regs.h.al=1; //Get version number
regs.h.ah=0x30; //Get version function 30h
int86(0x21, & regs, & regs); //Call DOS
major=regs.h.al; //Get major version no.
minor=regs.h.ah; //Get minor version no.

printf("This is DOS version %i, release %i",major,minor);
}

---

NOTE: In Line 11 & and regs are supposed to be joined, but if I join it posts this sign ®.

I get a lot of error messages and it won't compile my program. Here are the error messages:

Error E2450 dosver.c 7: Undefined structure 'REGS' in function main
Error E2449 dosver.c 7: Size of 'regs' is unknown or zero in function main
Error E2450 dosver.c 7: Undefined structure 'REGS' in function main
Error E2450 dosver.c 7: Undefined structure 'REGS' in function main
Error E2449 dosver.c 7: Size of 'regs' is unknown or zero in function main
Error E2451 dosver.c 9: Undefined symbol 'h' in function main
Error E2451 dosver.c 10: Undefined symbol 'h' in function main
Warning W8065 dosver.c 11: Call to function 'int86' with no prototype in function main
Error E2451 dosver.c 12: Undefined symbol 'h' in function main
Error E2451 dosver.c 13: Undefined symbol 'h' in function main
*** 9 errors in Compile ***

I have taken this program from a C book (C for Dummies Volume One), and I copied it exactly, but it still doesn't work. Can anyone help me?

how old is your book? I don't know much about what your problem could be, but maybe the book was using an earlier OS where you had control of full dos, not like with newer OS' such as WinXP,ME, etc. that would make your code invalid

I don't think Borland 5.5 supports interrupts, if you still want to compile this code, try another compiler, an older one like Turbo C, it should work there. My suggestion would be, leave interrupts and DOS, they're all dead.

>void main()
This is incorrect, pass trough the FAQ and see why it is wrong.

Good luck with your code,
Serruya.

1) Your compiler might not like the fact that you're using '.cpp' extensions, as this typically means "C++".

2) Main never returns void. It always returns an int. Thus, every program you write takes one of these two forms:

Code:

---

int main( void )
{
    ...stuff...

    return 0;
}

---

Or:

Code:

---

int main( int argc, char *argv[]  )
{
    ...stuff...

    return 0;
}

---

Naturally the return value doesn't always have to be zero, but the main thing to note here is that you always return an integer.

3) It's possible you're not including the correct header file, or that your compiler simply doesn't contain the needed information. (IE: Not all compilers are DOS compilers.)

[edit]Curses, foiled again![/edit]

Quzah.

Thanks for all the help!!! I actually save my source code with the .c at the end instead of .cpp. And thanks for the comments about void main(), I will use int from now on. I think I will have to get another compiler to run the program, although I know using it is a dead art, but I just want to know how it works. Thanks all, for your help.

I just compiled it on my XP system and the program compiled and actually ran correctly, giving me DOS ver 5, release 0
(ver gave XP version 5.1.2600)

Granted I used a different version of Borland, but 5 should handle it fine. It was released long before DOS was dead.

Many interrupts though will not work in NT, 2000, and XP becaue they are not true DOS. I found reading CD sectors with interrupts didn't work.

Another compiler probably won't work at all unless it's Borland. Doesn't 5 also come with 4.5? Try that one.

Well, I have tried a lot of things and none work, but then I noticed that my compiler compiled by deafult in 32 bit, and my programs only runs in 16 bit. How do I make my compiler compile in 16 bit? Any one got any ideas? Thanks.

I don't know anything about Borland, but I'm sure that somewhere in your documentation it would tell you. You just have to go look for it.

I have looked at the help files but I can't really find what I am looking. What I do is this: I open the only possible folder in the help menu, Command Line Tools. Then I get all these C++ Builder tools, here they are:

File Description
BCC32.EXE C++ compiler (32-bit), command-line version
BPR2MAK.EXE Converts project file from XML to MAKE file format for use with command-line tools
BRC32.EXE Resource compiler (32-bit), command-line version
BRCC32.EXE Resource shell (32-bit)
CONVERT.EXE Converts .DFM form files into a .TXT file format
CPP32.EXE C preprocessor (32-bit), command-line version
DCC32.EXE Object Pascal compiler (32-bit), command-line version
FCONVERT.EXE Converts text files between OEM and ANSI formats
GREP.EXE File search utility
ILINK32.EXE Incremental linker (32-bit), command-line version
IMPDEF.EXE Utility used when building apps with Libraries
IMPLIB.EXE Utility used when building apps with Libraries
MAKE.EXE Make utility
REGSRVR.EXE Registers ActiveX and OLE server .DLLs
RLINK32.DLL Resource linker (32-bit)
TDUMP.EXE File dump utility
TLIB.EXE Utility for maintaining static-link libraries
TLIBIMP.EXE (Type Library Import) tool. Takes existing type libraries and creates C++Builder Interface files. Incorporated into the Type Library editor.
TOUCH.EXE Change files stamps to current date/time
TRIGRAPH.EXE Converts 3-character trigraph sequences into single characters
VCTOBPR.EXE Converts Microsoft Visual C++ 5.0 and 6.0 project (.DSP) and workspace (.DSW) files to their equivalent Borland C++Builder files
WS32.EXE WinSight32, 32-bit utility to watch Windows messages

Now each of the Command Line Tools (file in blue), has a help menu, but which one of those do I enter to find how to make 16 bit programs. Thanks.

The test I compiled that worked was with Turbo C++ ver 1.00, Turbo Link ver 3.0 -- no surprises.

If you run BCC32 from the command line without parameters, you should get a list of all the command line switches. There may be one to compile 16bit code. BCC is the "Borland C Compiler".