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Re: Can anyone see a way to improve this ?

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mdj <mdj.mdj@gmail.com> writes:

> Hi,
>
> Below is a memory test loop for 1 page - assume the high order bytes
> get replaced for each page being tested. Zero page is deliberately
> avoided - this runs in either the language card or the $800-$BFFF area
> of main memory, testing pages of auxiliary memory without assuming any
> given byte of aux memory works.
>
> The obvious one is to unroll, which I'll do. Just wondering if I'm
> missing something else obvious.
>
> Thanks,
>
> Matt
>
>
>          LDX   #$00
> NEXTBYTE LDY   #$08
>          LDA   #$01
> NEXTBIT  EOR   #$FF       ; Set and check complement first
>          STA   $2000,X
>          CMP   $2000,X
>          BNE   ERROR
>          EOR   #$FF
>          STA   $2000,X
>          CMP   $2000,X
>          BEQ   CONT
> ERROR    JSR   FLAGERR
> CONT     ASL
>          DEY
>          BNE   NEXTBIT
>          INX
>          BNE   NEXTBYTE
>          RTS
> FLAGERR  RTS              ; Record this meaningfully in the future
>
>
>

For a thorough discussion of strong memory-checkers, see this article:

    http://www.ganssle.com/articles/ramtest.htm

I guess it depends on how confident you are in the machine's RAM in the
first place.

--
Jerry    awanderin at gmail dot com

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Thread

Can anyone see a way to improve this ? mdj <mdj.mdj@gmail.com> - 2014-10-27 05:04 -0700
  Re: Can anyone see a way to improve this ? "Anton Treuenfels" <teamtempest@yahoo.com> - 2014-10-27 08:38 -0500
  Re: Can anyone see a way to improve this ? Vladimir Ivanov <none@none.tld> - 2014-10-27 15:56 +0200
    Re: Can anyone see a way to improve this ? Michael J. Mahon <mjmahon@aol.com> - 2014-10-27 13:21 -0500
      Re: Can anyone see a way to improve this ? mdj <mdj.mdj@gmail.com> - 2014-10-27 17:48 -0700
        Re: Can anyone see a way to improve this ? Snertking <SNERTKING@GMAIL.COM> - 2014-10-27 21:28 -0400
          Re: Can anyone see a way to improve this ? mdj <mdj.mdj@gmail.com> - 2014-10-27 22:45 -0700
            Re: Can anyone see a way to improve this ? Michael J. Mahon <mjmahon@aol.com> - 2014-10-29 10:33 -0500
              Re: Can anyone see a way to improve this ? mdj <mdj.mdj@gmail.com> - 2014-10-29 22:54 -0700
                Re: Can anyone see a way to improve this ? qkumba <peter.ferrie@gmail.com> - 2014-10-31 14:46 -0700
      Re: Can anyone see a way to improve this ? Snertking <SNERTKING@GMAIL.COM> - 2014-10-27 21:25 -0400
      Re: Can anyone see a way to improve this ? michael.pohoreski@gmail.com - 2014-12-30 10:12 -0800
  Re: Can anyone see a way to improve this ? awanderin <awanderin@gmail.com> - 2014-10-27 21:35 -0600

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