Path: utzoo!mnetor!uunet!husc6!bu-cs!spike
From: spike@bu-cs.BU.EDU (Spike)
Newsgroups: comp.sys.apple
Subject: Re: Block moves
Message-ID: <21774@bu-cs.BU.EDU>
Date: 18 Apr 88 17:10:41 GMT
References: <8804172225.aa09835@SMOKE.BRL.ARPA>
Reply-To: spike@bu-it.bu.edu (Joe Ilacqua)
Followup-To: comp.sys.apple
Organization: Boston University Distributed Systems Group
Lines: 68

In article <8804172225.aa09835@SMOKE.BRL.ARPA> STEIN@UCONNVM.BITNET writes:
<Can someone give me an example using a block move (MVP or MVN)
>on the 65816?
<
>I know that you put the starting address (lower 16 bits) in X,
<destination address (lower 16 bits) in Y, the # of blocks less 1
>in the accumulator and then include the instruction
<
>mvp  sourcebank,destbank
<
>but I'm not certain how to put the source and destination banks
<in there.  My guess is that if I have statements such as:
>
<source ds 500
>dest   ds 500

	Well, the operands are the 8bit addresses of banks of 64K.
They can not be bigger than 255.


The example from Eyes & Lichty is along these lines:

lda count		;load C number of bytes to be moved minus 1
ldx source		;load the source address into X
ldy dest		;load the destination address Y

mvn s_bank,d_bank	;move a block 
			;$2000 bytes from $2000 to $4000 on bank 0
rts

count  dc A'$1FFF'	;$2000 - 1
source dc A'$2000'	;Source address
dest   dc A'$4000'	;destination address
s_bank dc I1'0'		;source bank
d_bank dc I1'0'		;destinaton bank


<somewhere in my program and want to move say 25 bytes starting at
>source+60 to a location starting at dest+90 I can do something like
<the following:

	What you want is some thing like:

lda source
clc		
adc #60			;Add 60 to source
tax			;put it in X
lda dest
clc	
adc #90			;Add 90 to dest
tay			;put it in Y
lda count		; load number of bytes to move

mvp s_bank,d_bank	;move block  25 bytes from $500 + 60 to $500 + 90
			;on bank 0

count  dc A'$18'	;25 - 1 = $18
source dc A'$500'	;Source address  
dest   dc A'$500'	;destination address
s_bank dc I1'0'		;source bank 	 ->Change this to what ever
d_bank dc I1'0'		;destinaton bank ->you are working on

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