Int 67H [EMS 4.0] Function 5BH (91) Subfunction 06H Enable DMA on alternate map register set

Associates a DMA channel with an alternate map register set.

Call with:

AH = 5BH

AL = 06H

BL = alternate map register set

DL = DMA channel number

Returns:

If function successful

AH = 00H

If function unsuccessful

AH = error code

Notes:

If a DMA channel is not assigned to a specific register set, DMA for that channel will be mapped through the current register set.

If zero is specified as the alternate map register set, no special action is taken on DMA accesses for the specified DMA channel.

This function is intended for use by operating systems only and can be disabled by the operating system at any time.