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Groups > comp.os.msdos.programmer > #3225

Re: scan for a-z

From Rod Pemberton <invalid@lkntrgzxc.com>
Newsgroups comp.os.msdos.programmer
Subject Re: scan for a-z
Date 2019-04-02 18:03 -0400
Organization Aioe.org NNTP Server
Message-ID <q80m3b$1m9j$2@gioia.aioe.org> (permalink)
References <ja45aepid2pe3kgka19s1011br325ph479@4ax.com> <c227f968-52f0-4285-8b73-2f13343c9016@googlegroups.com> <alpine.BSF.2.02.1904021237040.63863@frieza.hoshinet.org> <ic47aede9ffq719atu7kbiikaemr0ecokr@4ax.com>

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On Tue, 02 Apr 2019 16:48:41 +0000
T. Ment <t.ment@protocol.invalid> wrote:

> On Tue, 2 Apr 2019 12:40:41 -0400, Steve Nickolas wrote:

> >Now, I don't speak 8086 asm, so bear with me, because I'm going to
> >use the only dialect I know - 6502.  But the logic would probably be
> >the same as 8086.
> >
> >ptr        =        $04
> >entry:    ldy       #$00
> >@1:       lda       (ptr), y
> >           beq       @3
> >           cmp       #'a'
> >           bcc       @2        ; less than
> >           cmp       #'z'+1
> >           bcs       @2        ; greater or equal
> >           and       #$5F
> >           sta       (ptr), y
> >@2:       iny
> >           bne       @1
> >@3:       rts  
> 
> I have no knowledge of 6502. If anyone can translate to 8086, please
> do.

It's been a long time since I did 6502.  But, roughly translated ...


  entry:     cld
             mov esi,[ptr]   ; ptr contains address of buffer
             mov edi,esi
             add edi,length_of_buffer+1
  @1:        lodsb
             or al,al        ; set flags
              jz  @3         ; nul terminated buffer/string
              cmp  al,'a'
              jb  @2
              cmp  al,'z'+1
              jae @2
              and  al,5Fh
              dec esi
              stosb
  @2:         cmp esi,edi
              jne @1
  @3:        ret


For x86, XLATB is a better solution, since the "complicated" 6502
indirect addressing modes don't exist on x86.
http://qcd.phys.cmu.edu/QCDcluster/intel/vtune/reference/vc327.htm


Rod Pemberton
-- 
The lesson for Boeing.  You push the nose of a plane down, and planes
go down.

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Thread

scan for a-z T. Ment <t.ment@protocol.invalid> - 2019-04-01 22:43 +0000
  Re: scan for a-z "Alexei A. Frounze" <alexfrunews@gmail.com> - 2019-04-01 21:04 -0700
    Re: scan for a-z T. Ment <t.ment@protocol.invalid> - 2019-04-02 16:31 +0000
    Re: scan for a-z Steve Nickolas <usotsuki@buric.co> - 2019-04-02 12:40 -0400
      Re: scan for a-z T. Ment <t.ment@protocol.invalid> - 2019-04-02 16:48 +0000
        Re: scan for a-z Rod Pemberton <invalid@lkntrgzxc.com> - 2019-04-02 18:03 -0400
        Re: scan for a-z Peter 'Shaggy' Haywood <phaywood@alphalink.com.au> - 2019-04-17 23:56 +1000
  Re: scan for a-z "R.Wieser" <address@not.available> - 2019-04-02 09:00 +0200
    Re: scan for a-z "Kerr-Mudd,John" <notsaying@invalid.org> - 2019-04-02 09:06 +0000
      Re: scan for a-z "R.Wieser" <address@not.available> - 2019-04-02 14:37 +0200
  Re: scan for a-z Herbert Kleebauer <klee@unibwm.de> - 2019-04-02 12:39 +0200
    Re: scan for a-z "Kerr-Mudd,John" <notsaying@invalid.org> - 2019-04-02 14:27 +0000
      Re: scan for a-z Herbert Kleebauer <klee@unibwm.de> - 2019-04-02 20:17 +0200
        Re: scan for a-z "Kerr-Mudd,John" <notsaying@invalid.org> - 2019-04-02 19:16 +0000
        Re: scan for a-z wolfgang kern <nowhere@never.at> - 2019-04-03 16:13 +0200
          Re: scan for a-z T. Ment <t.ment@protocol.invalid> - 2019-04-03 19:36 +0000
          Re: scan for a-z "Kerr-Mudd,John" <notsaying@invalid.org> - 2019-04-04 14:43 +0000
            Re: scan for a-z wolfgang kern <nowhere@never.at> - 2019-04-05 00:41 +0200
  Re: scan for a-z JJ <jj4public@vfemail.net> - 2019-04-02 19:53 +0700
  Re: scan for a-z Mateusz Viste <mateusz@cant.remember> - 2019-04-02 13:00 +0000
    Re: scan for a-z T. Ment <t.ment@protocol.invalid> - 2019-04-02 16:44 +0000
  Re: scan for a-z Rod Pemberton <invalid@lkntrgzxc.com> - 2019-04-02 18:04 -0400
    Re: scan for a-z "Kerr-Mudd,John" <notsaying@invalid.org> - 2019-04-03 09:31 +0000
      Re: scan for a-z "Alexei A. Frounze" <alexfrunews@gmail.com> - 2019-04-03 02:48 -0700
        Re: scan for a-z "Kerr-Mudd,John" <notsaying@invalid.org> - 2019-04-03 12:25 +0000
          Re: scan for a-z Rod Pemberton <invalid@lkntrgzxc.com> - 2019-04-03 18:05 -0400
      Re: scan for a-z Bogus@Embarq.com (Steve) - 2019-04-03 11:58 +0000
  Re: scan for a-z wolfgang kern <nowhere@never.at> - 2019-04-03 15:58 +0200
    Re: scan for a-z wolfgang kern <nowhere@never.at> - 2019-04-03 16:05 +0200
    Re: scan for a-z "R.Wieser" <address@not.available> - 2019-04-03 17:40 +0200
    Re: scan for a-z "R.Wieser" <address@not.available> - 2019-04-03 17:47 +0200

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