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Re: BIOS limits on CD boot ?

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"wolfgang kern" <nowhere@never.at> wrote in message 
news:mmull1$7nc$1@speranza.aioe.org...

...

>> When you work out how multiple sessions are laid out do tell. IIRC 
>> each session has a long lead-in which is presumably made up of many 
>> unused 2k sectors and possibly just continues the sector numbering 
>> from where the last session left off (though I am not sure how well 
>> it could do that physically).

...

> I checked on bootable CD's created by Nero and figured that this 
> Multi-
> session issue is just a matter of not enough memory to write the whole 
> CD/DVD at once (ie: the 2GB limit on windoze).

I think it is more than that. AIUI the intention of multiple sessions is 
to allow an OD to appear to be updated. In each case the last session 
defines the visible contents of the entire OD including all the changed 
directory structures and any disc meta data. That allows, for example, a 
file to be 'deleted' by omitting it from a later directory even though 
the original file content still exists at an earlier point on the disc.

> So this Lead IN- lead OUT-sequences may be only required for multi-
> session writes (to tell the write-tool where to start next lateron).

That sounds about right though I am not sure how the transition between 
a lead-out of one session and the lead-in of the next would appear on an 
ISO image. Presumably a real optical disc cannot cleanly join the next 
session on to the end of the old one though that may not matter as long 
as we know how sector numbering is done across the transition.

> Of course a first written image cannot know where following parts will 
> reside, even it could calculate that from knowing its own size,
> but additive multi-session-records can't be shown in the primary 
> volume descriptors and friends ?

As I say, I think the later sessions replace all changed directory and 
meta-data records.

James

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BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-19 13:44 +0200
  Re: BIOS limits on CD boot ? "James Harris" <james.harris.1@gmail.com> - 2015-06-19 14:15 +0100
    Re: BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-19 19:07 +0200
      Re: BIOS limits on CD boot ? Melzzzzz <mel@zzzzz.com> - 2015-06-19 19:22 +0200
        Re: BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-20 08:50 +0200
      Re: BIOS limits on CD boot ? "James Harris" <james.harris.1@gmail.com> - 2015-06-20 09:07 +0100
        Re: BIOS limits on CD boot ? "James Harris" <james.harris.1@gmail.com> - 2015-06-20 15:43 +0100
          Re: BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-21 06:10 +0200
            Re: BIOS limits on CD boot ? "James Harris" <james.harris.1@gmail.com> - 2015-06-21 18:13 +0100
              Re: BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-22 09:55 +0200
                Re: BIOS limits on CD boot ? "James Harris" <james.harris.1@gmail.com> - 2015-06-22 12:04 +0100
                Re: BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-30 20:03 +0200
                Re: BIOS limits on CD boot ? "James Harris" <james.harris.1@gmail.com> - 2015-07-01 11:19 +0100
  Re: BIOS limits on CD boot ? "Benjamin David Lunt" <zfysz@fysnet.net> - 2015-06-19 10:56 -0700
    Re: BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-20 08:55 +0200
  Re: BIOS limits on CD boot ? "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-06-19 18:15 -0400
    Re: BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-20 09:18 +0200
      Re: BIOS limits on CD boot ? "Benjamin David Lunt" <zfysz@fysnet.net> - 2015-06-20 07:43 -0700
  Re: BIOS limits on CD boot ? "wolfgang kern" <nowhere@never.at> - 2015-06-21 16:04 +0200
    Re: BIOS limits on CD boot ? "James Harris" <james.harris.1@gmail.com> - 2015-06-22 12:13 +0100

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