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Magnum One
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Magnum One (Mid-American Digital) (Disc Manufacturing).iso
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d12
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emstools.arc
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EMMLIB.ARC
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EMM16_B.ASM
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Assembly Source File
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1990-02-04
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5KB
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88 lines
;-----------------------------------------------------------------------------;
; MODULE NAME: EMM16_B.ASM ;
; ;
; FUNCTION NAME: set_partial_context ;
; ;
; DESCRIPTION: This function provides a mechanism for restoring the ;
; mapping context for specific mappable memory regions ;
; in a system. Because this function restores only a ;
; subset of the mapping context (not the entire system's ;
; mapping context), it uses much less memory for the save ;
; structure and is potentially faster than set_context. ;
; The function copies the contents of the source ;
; structure to selected mapping hardware on each ;
; expanded memory board. The application passes a ;
; far pointer to the source structure. ;
; ;
; Use this function instead of save_context & ;
; restore_context if you need to save or restore the ;
; mapping context but don't want to (or have to) use a ;
; handle. ;
; ;
; PASSED: &source_context: ;
; is a far pointer to the source structure of the ;
; mapping context to be restored. ;
; The structure member is described here: ;
; ;
; source_context.reserved: ;
; is a character array which is reserved for use by ;
; the memory manager. In this instance it contains ;
; the data for the mapping hardware state. ;
; ;
; RETURNED: status: ;
; is the status EMM returns from the call. All other ;
; returned results are valid only if the status ;
; returned is zero. Otherwise they are undefined. ;
; ;
; C USE CONVENTION: unsigned int status; ;
; CONTEXT_STRUCT source_context; ;
; ;
; status = set_partial_context (&source_context); ;
;-----------------------------------------------------------------------------;
.XLIST
PAGE 60,132
IFDEF SMALL
.MODEL SMALL, C
ENDIF
IFDEF MEDIUM
.MODEL MEDIUM, C
ENDIF
IFDEF LARGE
.MODEL LARGE, C
ENDIF
IFDEF COMPACT
.MODEL COMPACT, C
ENDIF
IFDEF HUGE
.MODEL HUGE, C
ENDIF
INCLUDE emmlib.equ
INCLUDE emmlib.str
INCLUDE emmlib.mac
.LIST
.CODE
set_partial_context PROC \
USES DS SI, \
ptr_context:FAR PTR BYTE
;---------------------------------------------------------------------;
; do; ;
; . set the partial mapping context from the app to EMM; ;
;---------------------------------------------------------------------;
MOVE AX, set_partial_page_map_fcn
MOVE DS:SI, ptr_context
INT EMM_int
;---------------------------------------------------------------------;
; . return (EMM status); ;
; end; ;
;---------------------------------------------------------------------;
RET_EMM_STAT AH
set_partial_context ENDP
END