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Groups > comp.sys.apple2.programmer > #629

Re: Need help with a line in a BASIC program

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On 1/29/2013 3:03 PM, Michael J. Mahon wrote:
> Charlie<charlieDOTd@verEYEzon.net>  wrote:
>> On 1/29/2013 10:11 AM, A2CPM wrote:
>>> Hi!
>>>
>>>       One of the ProDOS format disk images for the Mill 6809 card have
>>> two BASIC
>>> programs for extracting all the files on a disk formatted by the FLEX
>>> operating system for the Apple ][.  The names are "FLEX.TO.PRODOS" and
>>> "FLEX.TO.DECIMAL".  The two programs are identical except for line
>>> 2030.
>>>
>>>       Expanded line 2030 from "FLEX.TO.DECIMAL":
>>> 2030 FOR I = 4 TO 255:
>>>          PRINT(PEEK(SA + I)):
>>>        NEXT I
>>>
>>>       Expanded line 2030 from "FLEX.TO.PRODOS":
>>> 2030 FOR I = 4 TO 255:
>>>          PRINT CHR$(PEEK(SA + I));:
>>>        NEXT I
>>>
>>>       "FLEX.TO.DECIMAL" runs in AppleWin but stops because the files
>>> written
>>> to the output disk are so much bigger than the files on the input disk
>>> so
>>> the output disk becomes full.  "FLEX.TO.PRODOS" breaks out of BASIC,
>>> showing
>>> "SYNTAX ERROR".
>>>
>>>       So, why does "FLEX.TO.DECIMAL" run and "FLEX.TO.PRODOS" not run?
>>> I was
>>> able to get all the files extracted from the FLEX disk with
>>> "FLEX.TO.DECIMAL"
>>> but would like to know how to change line 2030 to make
>>> "FLEX.TO.PRODOS" run.
>>>
>>> Willi
>>
>> Is one of the numbers PEEKED a 4?  A PRINT CHR$(4); will cause a SYNTAX
>> ERROR in the FOR/NEXT loop (at least in AppleWin).  Try running it
>> without the semi-colon to see if that's it.
>>
>> Charlie
>
> That was my point. Ctl-D signals ProDOS that the following PRINTed
> characters are a ProDOS command. Since the purpose of this loop is to copy
> arbitrary binary data to a text file (!), the semicolon is necessary to
> prevent the insertion of a CR after each byte.
>
> This loop will only work on files that do not contain ctl-Ds--not very
> useful for arbitrary data, an a bog-slow byte at a time copy.
>
> -michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon

Michael, your post hadn't showed up yet on my newsreader when I posted 
(you beat me by 5 minutes :-)
I only suggested removing the semi-colon to see if the SYNTAX ERROR went 
away, not to use it for copying data.  I should have been more clear on 
that.

Charlie

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Thread

Need help with a line in a BASIC program A2CPM <a2@wilserv.com> - 2013-01-29 07:11 -0800
  Re: Need help with a line in a BASIC program David Schmidt <schmidtd@my-deja.com> - 2013-01-29 10:48 -0500
    Re: Need help with a line in a BASIC program retrogear <larrygr510@gmail.com> - 2013-01-29 08:21 -0800
      Re: Need help with a line in a BASIC program BLuRry <brendan.robert@gmail.com> - 2013-01-29 08:34 -0800
    Re: Need help with a line in a BASIC program A2CPM <a2@wilserv.com> - 2013-01-29 09:31 -0800
      Re: Need help with a line in a BASIC program David Schmidt <schmidtd@my-deja.com> - 2013-01-29 13:15 -0500
        Re: Need help with a line in a BASIC program A2CPM <a2@wilserv.com> - 2013-01-29 10:35 -0800
    Re: Need help with a line in a BASIC program Michael J. Mahon <mjmahon@aol.com> - 2013-01-29 13:51 -0600
  Re: Need help with a line in a BASIC program Charlie <charlieDOTd@verEYEzon.net> - 2013-01-29 14:56 -0500
    Re: Need help with a line in a BASIC program Michael J. Mahon <mjmahon@aol.com> - 2013-01-29 14:03 -0600
      Re: Need help with a line in a BASIC program Charlie <charlieDOTd@verEYEzon.net> - 2013-01-29 15:34 -0500
    Re: Need help with a line in a BASIC program A2CPM <a2@wilserv.com> - 2013-01-29 12:21 -0800
      Re: Need help with a line in a BASIC program David Schmidt <schmidtd@my-deja.com> - 2013-01-29 15:40 -0500
        Re: Need help with a line in a BASIC program "Bill Buckels" <bbuckels@mts.net> - 2013-01-31 08:36 -0600
          Re: Need help with a line in a BASIC program gids.rs@sasktel.net - 2013-01-31 08:01 -0800

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