You must use _go32_conventional_mem_selector() and the functions dosmemget(), dosmemput(), movedata(), _farpeekX(), and _farpokeX() functions to access any absolute address in the lower memory. Using the _farpeekX() and _farpokeX() paradigm to access memory isn't slower than direct access (they compile into 2 machine instructions when optimizations are enabled).

The selector to use is _go32_info_block.selector_for_linear_memory in go32.h.