[SPG_Active_Members] Long-term Digital Preservation: your technical questions of Sept. 1

[Tim Shoppa]

Al Kossow <kossow at computerhistory.org> wrote:
> An alternative approach was the MIT Time Capsule File System, where they
> tried to do as much up-front decoding of the tape images as they could,
> assuming the knowledge on how to interpret the dump tapes would be lost.
>
> All of the AI Lab's archive tapes were recently recovered, and imaged in
> '.tap' (low-level image) format. I haven't heard if they plan on creating
> TCFS images from the new data (several thousand tape images).

Most old filesystems or tape archive formats are remarkably easy
to decode in the first place. They were created to fill
a very specific need and to do so without a lot of code. Same
applies to emulator image formats.

OTOH the "end all and be all formats" - ones that the developers
were told had to last not for months or years but for decades
or centuries - have considerable complexity, because they tried to
anticipate everything coming down the pike.  And because of the extra
time the developers were given they usually contain way too many
abstractions and levels and in the end require a lot of code. Even
worse, they require the coder to understand lots of concepts that
were never even necessary.

Tim.