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From: hsgj@batcomputer.TN.CORNELL.EDU (Dan Green)
Newsgroups: net.micro.cbm
Subject: Re: Turning BASIC ROM into RAM...
Message-ID: <230@batcomputer.TN.CORNELL.EDU>
Date: Wed, 7-May-86 01:55:34 EDT
Article-I.D.: batcompu.230
Posted: Wed May  7 01:55:34 1986
Date-Received: Sat, 10-May-86 12:26:55 EDT
References: <2167@caip.RUTGERS.EDU>
Reply-To: hsgj@batcomputer.UUCP (Dan Green)
Organization: Theory Center, Cornell University, Ithaca NY
Lines: 21

In article <2167@caip.RUTGERS.EDU> KOCYAN@BLUE.RUTGERS.EDU writes:
>From: KOCYAN@BLUE.RUTGERS.EDU
>   On the Commodore 64, is it possible to turn the BASIC ROM between addresses
>$A000 and $BFFF into RAM, and yet keep the BASIC routines there so that they
>can be modified?
>   I've tried changing the data-direction-register (location $0000), but that
>didn't seem to help at all.
>   Any advise would be greatly appreciated.  Thanks in advance.
>                                        Rob.

I am sure there will be many responses, but...  First thing you do is copy
the ROM to RAM by yourself.  In basic it would be something like:
   FOR I = 40960 TO 40960+8192: POKE I, PEEK(I): NEXT I
What this does is copy the BASIC ROM to the RAM that is sitting underneath
it.  Then you do the poke in location $0000 to turn off the BASIC ROM.  Now
you have BASIC running out of RAM, and can modify/trash any routines you
want to just by poking into $a000-$booo or by twiddling with a monitor.
-- 
Dan Green    Bitnet:  hsgj@cornella
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