PC Extra Super CD 1998 January/PCPLUS131.iso/DJGPP/V2/DJLSR201.ZIP/src/libc/pc_hw/mem/dmgb.txh

Text File | 1996-01-30 | 916 b | 38 lines

@node dosmemgetb, memory
@subheading Syntax

@example
#include <sys/movedata.h>

void _dosmemgetb(unsigned long offset, size_t xfers, void *buffer);
@end example

@subheading Description

This function transfers data from MS-DOS's conventional memory space
to the program's virtual address space, using only byte transfers.
The @var{offset} is a physical address, which can be computed from a
real-mode segment/offset pair as follows:

@example
offset = segment * 16 + offset;
@end example

The @var{xfers} is the number of bytes to transfer, and @var{buffer} is
a pointer to somewhere in your virtual address space (such as memory
obtained from @code{malloc}) where the data will go.

@subheading Return Value

None.

@subheading Example

@example
unsigned short shift_state;
dosmemgetb(0x417, 2, &shift_state);
if (shift_state & 0x0004)
  /* Ctrl key pressed */;
@end example