Int 67H [EMS 3.0] Function 44H (68) Map expanded memory page

Maps one of the logical pages of expanded memory assigned to a handle onto a physical memory page that can be accessed by the CPU.

Call with:

AH = 44H

AL = physical page

BX = logical page

DX = EMM handle

Returns:

If function successful

AH = 00H

If function unsuccessful

AH = error code

Notes:

The logical page number is in the range {0...n-1}, where n is the number of pages allocated or reallocated to the handle by a previous call to Int 67H Function 43H, 51H, or 5AH. Logical pages allocated by Int 67H Function 43H or Function 5AH Subfunction 00H are always 16 KB long; logical pages allocated by Int 67H Function 5AH Subfunction 01H are referred to as raw pages and are not necessarily 16 KB.

[EMS 3] The physical page is in the range 0—3 and lies within the EMM page frame, whose base address is obtained from Int 67H Function 41H.

[EMS 4.0] A list of the available physical pages and their addresses may be obtained from Int 67H Function 58H Subfunction 00H.

[EMS 4.0] If this function is called with BX = -1, the specified physical page is unmapped (made inaccessible for reading or writing).