Groups > comp.sys.apple2.programmer > #258

Re: ProDOS Assembly Tools docs

From	markpmlim@yahoo.com.sg
Newsgroups	comp.sys.apple2.programmer
Subject	Re: ProDOS Assembly Tools docs
Date	2012-04-07 00:45 -0700
Organization	http://groups.google.com
Message-ID	<17993939.865.1333784727827.JavaMail.geo-discussion-forums@pbcqs8> (permalink)
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On Friday, April 6, 2012 6:06:16 AM UTC+8, A2CPM wrote:
> Hi, y'all!
> 
>     I've found what appears to be coding errors in "LINKER".  The
> first snippet of code that seems to be in error is as follows:
> 	LDA	WORDZ80
> 	SEC
> 	SBC	PTRZ84
> 	STA	RDWRPL+6
> 	LDA	WORDZ80+1
> 	SBC	PTRZ84+1
> 	STA	RDWRPL+6
> The last line should be '+7' not '+6'.
>     The second snippet of code that seems to be in error is as
> follows:
> L35B3	CMP	#'A
> 	BCC	L35A7
> 	CMP	#'F
> 	BCS	L35B1
> 	SBC	#6
> 	CLC
> 	RTS
> The third line should be '#'G' if the subroutine is intended to return
> with the carry flag clear if the accumulator contains an ASCII
> hexadecimal digit on entry to the subroutine.
>     Further analysis of the code may reveal if these apparent coding
> errors are real bugs.
> 
> Willi

>	LDA     WORDZ80
 >	SEC
 >	SBC     PTRZ84
 >	STA     RDWRPL+6
 >	LDA     WORDZ80+1
 >	SBC     PTRZ84+1
 >	STA     RDWRPL+6
 
 I agree this is a bug. However, it may never get executed if ESD is < 5K.
 
 >L35B3 CMP     #'A
 >      BCC     L35A7
 >      CMP     #'F
 >      BCS     L35B1
 >      SBC     #6
 >      CLC
 >      RTS
 
 I suspect the function of this routine is to return (A)= $30-$3F if on
 entry (A) = '0'-'9' or 'A'-'F'

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ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-03-26 13:03 -0700
  Re: ProDOS Assembly Tools docs dog_cow@macgui.com (D Finnigan) - 2012-03-26 22:34 +0000
    Re: ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-03-26 17:11 -0700
      Re: ProDOS Assembly Tools docs dog_cow@macgui.com (D Finnigan) - 2012-03-27 15:54 +0000
        Re: ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-03-27 12:36 -0700
          Re: ProDOS Assembly Tools docs Antoine Vignau <antoine.vignau@laposte.net> - 2012-03-27 13:42 -0700
            Re: ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-03-27 16:26 -0700
          Re: ProDOS Assembly Tools docs Steven Hirsch <snhirsch@gmail.com> - 2012-03-28 18:22 -0400
            Re: ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-03-28 17:06 -0700
              Re: ProDOS Assembly Tools docs A2CPM <a2@wilserv.com> - 2012-03-30 12:42 -0700
                Re: ProDOS Assembly Tools docs MarkLim <markpmlim@yahoo.com.sg> - 2012-04-07 01:03 -0700
                Re: ProDOS Assembly Tools docs MarkLim <markpmlim@yahoo.com.sg> - 2012-04-07 00:57 -0700
              Re: ProDOS Assembly Tools docs A2CPM <a2@wilserv.com> - 2012-04-05 07:34 -0700
                Re: ProDOS Assembly Tools docs A2CPM <a2@wilserv.com> - 2012-04-05 08:50 -0700
                Re: ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-04-05 09:55 -0700
                Re: ProDOS Assembly Tools docs dog_cow@macgui.com (D Finnigan) - 2012-04-05 17:33 +0000
                Re: ProDOS Assembly Tools docs A2CPM <a2@wilserv.com> - 2012-04-05 15:06 -0700
                Re: ProDOS Assembly Tools docs markpmlim@yahoo.com.sg - 2012-04-07 00:45 -0700
                Re: ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-04-05 21:09 -0700
                Re: ProDOS Assembly Tools docs Steven Hirsch <snhirsch@gmail.com> - 2012-04-06 08:09 -0400
                Re: ProDOS Assembly Tools docs "Bill Garber" <willy46pa@comcast.net> - 2012-04-07 21:03 -0400
                Re: ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-04-07 19:02 -0700
                Re: ProDOS Assembly Tools docs David Schmenk <dschmenk@gmail.com> - 2012-04-07 20:16 -0700
                Re: ProDOS Assembly Tools docs A2CPM <a2@wilserv.com> - 2012-04-08 20:52 -0700

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