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51 lines
1.3 KiB
Plaintext
51 lines
1.3 KiB
Plaintext
;EASE$$$ READ ONLY COPY of file “SetProcessorLevel.a”
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; 1.1 CCH 11/10/1988 Fixed Header.
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; 1.0 CCH 11/ 9/1988 Adding to EASE.
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; OLD REVISIONS BELOW
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; 1.0 EMT 3/22/88 First time adding Notification Manager sources
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; END EASE MODIFICATION HISTORY
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;_______________________________________________________________________
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; SetProcessorLevel.a
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;
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; by Ed Tecot
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; Copyright 1987 Apple Computer, Inc.
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;
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; This file contains two short routines which enable the processor state
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; modified from C.
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;
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; Code by Erich Ringewald.
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; Color Commentary by Ed Tecot
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;_______________________________________________________________________
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CASE OBJ
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STRING ASIS
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; disable()
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; Disables all interrupts by setting the processor state to level 7.
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; Returns the current level.
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disable PROC EXPORT
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MOVEQ #0, D0
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MOVE SR, D0 ; Get status register
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LSR #8, D0 ; Shift priority into low byte
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AND #7, D0 ; Mask out trace/supervisor
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ORI #$0700, SR ; Force processor to level 7
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RTS
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ENDPROC
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; spl(level)
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; Sets the processor level to its argument.
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spl PROC EXPORT
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MOVE SR, D0 ; Get status register
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MOVE 6(SP), D1 ; Get desired level
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LSL #8, D1 ; Put it into high byte
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AND #$F8FF, D0 ; Mask out level bytes in SR copy
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OR D1, D0 ; And put ours in
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MOVE D0, SR ; And set the SR
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RTS
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ENDPROC
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END
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