register structs - problem declaring

This is a discussion on register structs - problem declaring within the C Programming forums, part of the General Programming Boards category; What I am trying to do is play around with bios interrupts, while reading TYAC. I can't seem to declare ...

  1. #1
    Registered User Kagey's Avatar
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    register structs - problem declaring [resolved]

    What I am trying to do is play around with bios interrupts, while reading TYAC. I can't seem to declare the register structs. here is the code that i use:
    Code:
    #include <dos.h>
    void current_date( int *month, int *day, int *year) {
        union REGS inregs, outregs;
    /* ... */
    }
    i get the errors:

    4 C:\dev\c\BiosFunctions\currentDate.c
    storage size of `inregs' isn't known

    any suggestions?

    thanks
    Last edited by Kagey; 11-10-2002 at 03:55 PM.

  2. #2
    End Of Line Hammer's Avatar
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    Your compiler doesn't know what your talking about. Maybe you need a real DOS compiler... what are you using anyway?
    When all else fails, read the instructions.
    If you're posting code, use code tags: [code] /* insert code here */ [/code]

  3. #3
    Registered User Kagey's Avatar
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    dev-c++. I should be able to compile it an any compiler, including borland and ms.

    I also tried to include a file with
    Code:
    struct XREG {
    	unsigned int ax;
    	unsigned int bx;
    	unsigned int cx;
    	unsigned int dx;
    	unsigned int si;
    	unsigned int di;
    	unsigned int cflag;
    };
    
    struct HREG {
    	unsigned char al, ah;
    	unsigned char bl, bh;
    	unsigned char cl, ch;
    	unsigned char dl, dh;
    };
    
    union REGS {
    	struct XREG x;
    	struct HREG h;
    };
    directly into my source, but still didnt work.

  4. #4
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    doesnt that function require the time.h library

  5. #5
    Registered User Kagey's Avatar
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    no man, its a custom function that uses bios interrupts to get the time from cmos i think.

  6. #6
    Registered User Kagey's Avatar
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    anyway, this is wierd, i pasted the structs and union into my actual source file and it compiles.

    i dotn what to do this though, i want my register structs to be in a header file that i can include in everything.

  7. #7
    ATH0 quzah's Avatar
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    There are no "register structs" as far as I'm aware, that are standard C structures. As such, if you want them in a header file, make a header and stick them in there:
    Code:
    myheader.h begins
    #ifndef MYHEADER
    #define MYHEADER
    struct somestruct {
    };
    struct someotherstruct {
    };
    union someunion {
        struct somestruct something;
        struct someotherstruct somethingelse;
    };
    #endif
    myheader.h ends
    Then, in your little proggie, just include "myheader.h". Vola. Problem solved.

    Quzah.
    Hope is the first step on the road to disappointment.

  8. #8
    Registered User Kagey's Avatar
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    that's exactly what i did. i have made headers before, but this doesnt seem to be working.. strange

  9. #9
    Banned master5001's Avatar
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    Your compiler doesn't know what your talking about. Maybe you need a real DOS compiler... what are you using anyway?
    That sounds about right. Win32 (specifically win 98 and later versions of win 95) takes advantage of a cpu mode called protected mode. You should be doing this with a dos compiler (borland's turbo c is excelent for this task). Just because you have a header files doesn't mean that you are magically going to get your code to operate.

  10. #10
    Registered User Kagey's Avatar
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    ok guys,

    This has nothing to do with dos. it has to do with bios interrupts. the dos header file should contain the proper structs that i can use with the int86 function. that is all. however, my dos header file doesn't seem to have these declarations in them, so i have to use my own header file.

    I think the problem is that dev-c++ isnt bringing in my header file properly. I think this because when i modify the actual dos.h header file by puting in the register structs, my code compiles.

    When i use my own header file, however, it won't compile. the code im using is like:

    #include "register_structs.h"

    and the header file is in the same directory and project. yet, it doesnt actually get included for some reason

  11. #11
    Registered User Kagey's Avatar
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    my header file was fooked. everything about this problem is fine, thanks.

  12. #12
    Banned master5001's Avatar
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    Ah okay, i see what you are doing. Anyways, you problem sounds weird...Since dev-c++'s support for mingw 3.2 is poor I've been using makefiles lately. However, you may consider adding the directory of the header to your includes list (look under Project->Project Options). The specifics of adding a new include path depends on which dev-c++ you are using but you should be able to find it okay.

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