<div>
The compiler does not know what a 'REGS' is.<br />
REGS has not been defined.
</div>


The compiler does not know what a 'REGS' is.
REGS has not been defined.

<div>
Are you using a 32 bit compiler?<br />
If so, you will not find the REGS structure there.<br />
You will need MSVC 1.52c or earlier (console app, too).
</div>


Are you using a 32 bit compiler?
If so, you will not find the REGS structure there.
You will need MSVC 1.52c or earlier (console app, too).

<div>
<div class="content wysiwyg-content">
#define VIDEO 0x10<br />
<br />
main()<br />
{<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;union REGS regs;<br />
&nbsp; &nbsp; &nbsp;<br />
&nbsp; &nbsp; &nbsp;regs.h.ah=0x02;<br />
&nbsp; &nbsp; &nbsp;regs.h.bh=0x00;<br />
&nbsp; &nbsp; &nbsp;regs.h.dh=row;<br />
&nbsp; &nbsp; &nbsp;regs.h.dl=col;<br />
&nbsp; &nbsp; &nbsp;int86(VIDEO,&amp;regs,&amp;regs);<br />
}<br />
Compile error<br />
'regs' uses undefined REGS<br />
left of '.h' must have struct/union type<br />
<br />
OK learning C using MS VC++<br />
Found code on net, what header file should be included?<br />
Can I even use this?<br />

</div>
</div>


#define VIDEO 0x10

main()
{
         union REGS regs;
     
     regs.h.ah=0x02;
     regs.h.bh=0x00;
     regs.h.dh=row;
     regs.h.dl=col;
     int86(VIDEO,&regs,&regs);
}
Compile error
'regs' uses undefined REGS
left of '.h' must have struct/union type

OK learning C using MS VC++
Found code on net, what header file should be included?
Can I even use this?


Whats this error

C is a general-purpose, imperative computer programming language, supporting structured programming, lexical variable scope and recursion, while a static type system prevents many unintended operations. By design, C provides constructs that map efficiently to typical machine instructions, so it has found lasting use in applications that had formerly been coded in assembly language, including operating systems as well as various application software for computers ranging from supercomputers to embedded systems. It is distinct from C++ (which has its roots in C) and C#, and many later languages have borrowed directly or indirectly from C.