Compatibility: EMS 4.0+

Expects: AH    5bH

AL    subfn: 00H=Query alternate map register set

01H=Set alternate map register set

BL = new alternate map register set number

ES:DI => buffer to receive data

02H=Query alternate map register set array size

03H=Allocate alternate map register set

04H=Deallocate alternate map register set

05H=Allocate DMA register set

06H=Enable DMA on alternate map register set

BL = DMA register set number

DL = DMA channel number

ES:DI => buffer to receive data

07H=Disable DMA on alternate map register set

BL = alternate map register set number

08H=Deallocate DMA register set

BL = DMA register set number

Returns: AH    EMM status (0=successful)

BL    (5b00H) current active alternate register map set

(5b03H) alternate map registers set number

(5b05H) DMA register set number

ES:DI (5b00H) map register context save area (if BL=0)

DX    (5b02H) size of array

Info: This is designed for use by operating systems only and may be

disabled at any time.

These fns are used by an operating system in support of low-level

functions such as tampering with DMA.

See Also: INT 67H: EMM Services

Extended Memory Specification (XMS)

Interrupts and BIOS Services

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