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Re: RWTS return codes

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On Sunday, November 29, 2015 at 10:37:33 AM UTC-6, qkumba wrote:
> On Sunday, November 29, 2015 at 7:34:28 AM UTC-8, Mark Lemmert wrote:
> > On Thursday, November 26, 2015 at 2:50:31 PM UTC-6, Antoine Vignau wrote:
> > > What is unclear to me, Mark, is your explanations on the return code in your last message.
> > > 
> > > Are the error codes from the rwts after a dos call or not?
> > > 
> > > av
> > 
> > I am sorry for any confusion I created in my prior post.  
> > 
> > Could you clarify what you mean by "after a DOS call"? 
> > 
> > Since RWTS is a subroutine of the DOS software loaded into memory by the boot process, I think of a JSR to RWTS via assembly language as being a DOS call, but I am not sure if that is what you mean. 
> > 
> > In any event, if it helps..here is bit more info on how I am getting the RWTS error code (/aka return code)
> > 
> > My program calls RWTS via JSR $3ED9
> > 
> > After making the call, my program checks byt $0D of the IOB table for the return code. The location of the IOB table depends on where DOS gets loaded into memory.  On my system the IOB table starts at $B7E8, so byt $0D is located at $B754
> > 
> > The exact location of the IOB table is identified via JSR $03E3.
> 
> If you call through the file manager (JSR $03D6) directly, or indirectly via "PRINT CHR$(4)", then that's a DOS call.  In that case, RWTS will be called by DOS, and any error that is returned, or any error that results (e.g. sector was read correctly, but requested file does not exist) will be mapped to the DOS table.  If you call RWTS directly, then you have to deal only with the RWTS errors, and the returned carry flag is critical for that purpose.

Thank you for the additional insight! That is great to know more about how the DOS error codes relate to the RWTS return codes.

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RWTS return codes Mark Lemmert <mark.lemmert@gmail.com> - 2015-11-24 09:59 -0800
  Re: RWTS return codes qkumba <peter.ferrie@gmail.com> - 2015-11-24 14:41 -0800
    Re: RWTS return codes Mark Lemmert <mark.lemmert@gmail.com> - 2015-11-26 08:08 -0800
  Re: RWTS return codes gids.rs@sasktel.net - 2015-11-26 07:36 -0800
    Re: RWTS return codes Mark Lemmert <mark.lemmert@gmail.com> - 2015-11-26 08:15 -0800
      Re: RWTS return codes qkumba <peter.ferrie@gmail.com> - 2015-11-26 08:53 -0800
      Re: RWTS return codes gids.rs@sasktel.net - 2015-11-26 11:17 -0800
        Re: RWTS return codes Antoine Vignau <antoine.vignau@laposte.net> - 2015-11-26 12:50 -0800
          Re: RWTS return codes Mark Lemmert <mark.lemmert@gmail.com> - 2015-11-29 07:34 -0800
            Re: RWTS return codes qkumba <peter.ferrie@gmail.com> - 2015-11-29 08:37 -0800
              Re: RWTS return codes qkumba <peter.ferrie@gmail.com> - 2015-11-29 08:41 -0800
              Re: RWTS return codes Mark Lemmert <mark.lemmert@gmail.com> - 2015-12-02 14:15 -0800
        Re: RWTS return codes Mark Lemmert <mark.lemmert@gmail.com> - 2015-11-29 07:20 -0800

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