Re: [ARSCLIST] "hard drive on a shelf"

[Don Cox <doncox@xxxxxxxxxxxxxx>]

On 23/07/07, Steven C. Barr(x) wrote:

> ----- Original Message ----- 
> From: "Don Cox" <doncox@xxxxxxxxxxxxxx>
>> >> I think the most likely thing to fail on a hard drive long term is
>> >> capacitors on the circuit board.
>> >> 
>> >> But more likely is that, when the drive is brought out of its
>> >> cupboard
>> >> 25 years later, there will be no equipment to connect it to and no
>> >> operating system that can read the file format. Try getting data
>> >> off a
>> >> 25 year old cp/m drive today.
>> >> 
> 1) Modern-day capacitors do not have anywhere near the failure rate as
> do those we recall...especially if/when the devices in which they are
> included are not in use! IIRC (and I may be wrong here...?) current
> electrolytic units no longer allow evaporation of liquid electrolytes,
> but are as sealed as are other capacitors. Further, the concept of
> caps "sealed" with a wax coating is long since obsolete...!
> 
> 2) Although programs, and their inherent file formats, have come and
> gone over the years/decades...the basic format of information
> expressed in byte and/or bit form still remains functionally the same!
> I may have to search high and low for a 5.25" floppy drive (back when
> they were REALLY "floppy," eh...?!)...but once I find and install one,
> the ASCII content will be as readable today as it was back in 1986
> when I stored it...! 

Only if you have a DOS that knows how the blocks are arranged on the
disk. 

Otherwise, you have a large collection of snippets of files in
semi-random order. I have experience of trying to recover data from cp/m
disks with damaged directories. There are dozens of possible
arrangements for the sectors on cp/m disks.

Nowadays, there are many different filesystems in use, most much more
complex than those used 25 years ago. (FAT, widely used in memory
sticks, cameras, etc is basically a cp/m variant, and is the most
primitive system still in general use.)


> Yes...program- specific files CAN be unreadable
> without a working copy of <wotever>.exe, but in many cases (dBASE and
> most vintage word-processing applications, et al...) the data can
> still be recovered from the file contents. 

Image and audio files are difficult, especially if they are
compressed (as most image files are). 

> Further, given the inherent
> restriction that each new generation of digitalia MUST be able to use
> files created using the previous generation (otherwise gazillions of
> machines and digital files are instantly rendered useless...!), it
> seems unlikely that some 21st-century improvement in computer
> technology will wipe out everything...including vast amounts of stored
> information...that went before!
> 
> The CP/M example you cite actually refers to the VERY beginning of
> personal computers and computation...and was a format which existed
> for no more than a handful of years (although we inherited its 8.3
> filename format...!). As well, didn't it also use the same ASCII
> format for alphanumeric information?
> 
> Certainly, the bytes making up a program file would probably be
> totally unintelligible to a modern Wintel machine...just as are/were
> the bytes making up a Mac program. In fact, I'm not sure if it would
> be possible to create an application which could translate non-Wintel
> programmatic data into its Wintel equivalent (interesting thought,
> though...?!).
> 
> So...saved alphanumeric data will probably posess near-infinite
> readability. Digital sound files may or may not (although the question
> arises what sorts of new and different format will replace the CD
> and/or DVD without leaving a trace of its predecessors...?!)
> And...digital image files are even more likely to be struck "obsolete"
> in one fell swoop, since their digital content is NOT easily
> interpretable with respect to the pixels involved (again, I may be in
> error...?!).
> 
> However...on the first floor I have an IBM PS-1 machine, with an
> Intel 486SX processor, c. 1991! It works fine...as do the various
> programs stored on its hard drive. Further, it is likely to continue
> "working fine" until either lightning strikes the hydro wires in
> my neighbourhood, or my house unexpectedly bursts into flames, or
> either Al Qaeda or Chairman Putin (or the current government of
> the Maldive Islands...or Hell's Angels...or the Sopranos...or...)
> organizes the nuclear/biological/chemical/wotever destruction of
> Durham Region and Vicinity...
> 
> However...in a new interpretation of "Note the notes"...in any such
> crisis it is very likely that all my hand-taken, ink-on-paper "notes"
> would be reduced to illegible ash in a literal "flash"...?!
> 
> Steven C. Barr
Regards
-- 
Don Cox
doncox@xxxxxxxxxxxxxx