INT 67H 4fxxH: Get/Set Partial Page Map
Compatibility: EMS 4.0+
Expects: AH 4fH
AL subfn: 00H=Save some mapping registers
DS:SI=list of registers to query
ES:DI=buffer to receive data
01H=Restore some mapping registers
DS:SI=data obtained via subfn 00H
02H=Query buffer size for subfns 00H and 01H
BX=count of pages to be saved/restored
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Returns: AH EMM status (0=successful)
AL (subfn 02H) size, in bytes of buffer for data buffers
ES:DI (subfn 00H) buffer contains returned information
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Info: This fn is similar to INT 67H 4exxH, in that it saves/restores
the page mapping registers. This version lets you specify a
subset (e.g., save/restore just one or two pages).
Before using subfn 4f00H, you should use subfn 4f02H to see how
large of a buffer you will need.
DS:SI (subfn 4f00H) is a list that identifies which mapping registers
you wish to save. The list is formatted as:
Offset Size Contents
▀▀▀▀▀▀ ▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
+0 2 wPgCnt number of 16K pages to save
+2 2 wSeg1 segment of first physical pg to save
+4 2 wSeg2 segment of second physical pg to save
.
:
etc.
ES:SI (subfn 4f00H) is a buffer to receive mapping-register data. You
should use subfn 4f02H to see how large this should be.
See Also: INT 67H: EMM Services
Extended Memory Specification (XMS)
Interrupts and BIOS Services
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