Int 67H [EMS 4.0] Function 55H (85) Subfunctions 00H and 01H Map pages and jump

Alters the expanded memory mapping context and transfers control to the specified address.

Call with:

AH = 55H

AL = subfunction

0 = map using physical page numbers

1 = map using physical page segments

DX = EMM handle

DS:SI = segment:offset of buffer (see Notes)

Returns:

If function successful

AH = 00H

If function unsuccessful

AH = error code

Notes:

The buffer contains map-and-jump entries in the following format:

Offset Length Description 00H 4 far pointer to jump target 04H 1 number of pages to map before jump 05H 4 far pointer to map list (see below)

The map list in turn consists of DWORD (32-bit) entries, one per page. The first word of each entry contains the logical page number, and the second word contains the physical page number or segment (depending on the value in register AL) to which it should be mapped.

A request to map zero pages and jump is not considered an error; the effect is a simple far jump.