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CPM OPERATING SYSTEMS/CPM 3.X/CPM 3.0/3.0 PLM SOURCE/MOVE.ASM

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+	title 'bank & move module for CP/M3 linked BIOS'
+
+	cseg
+
+	public ?move,?xmove,?bank
+	extrn @cbnk
+
+	maclib z80
+	maclib ports
+
+?xmove:		; ALTOS can't perform interbank moves
+	ret
+
+?move:
+	xchg		; we are passed source in DE and dest in HL
+	ldir		; use Z80 block move instruction
+	xchg		; need next addresses in same regs
+	ret
+
+					; by exiting through bank select
+?bank:
+	push b				; save register b for temp
+	ral ! ral ! ral ! ani 18h	; isolate bank in proper bit position
+	mov b,a				; save in reg B
+	in p$bankselect			; get old memory control byte
+	ani 0E7h ! ora b		; mask out old and merge in new
+	out p$bankselect		; put new memory control byte
+	pop b				; restore register b
+	ret
+
+				;	128 bytes at a time
+
+	end