[TUHS] Early non-Unix filesystems?

Greg 'groggy' Lehey grog at lemis.com
Tue Mar 22 10:13:37 AEST 2016


On Monday, 21 March 2016 at  8:06:34 -0400, John Cowan wrote:
> Tony Finch scripsit:
>
>> I was slightly startled by the coolness of the idea when I found out that
>> nvi uses Berkeley DB as its storage layer; its recno access method
>> makes a text file look like a random-access array of strings.
>
> Classical sequential files, however, were simply random-access files
> such that seeking to line n was just a matter of seeking to byte
> n * MAXCHARSLINE.  The last time I actually used such a thing was
> on an early Tandem system when I was implementing the Software
> Tools.

You're presumably not talking about a Tandem format here.  Were you
working with Denis Winn?

> Editable source used a different format, ...

Presumably you *are* talking about Tandem's format here.  I always
looked at it as an indication of how badly optimization attempts could
go wrong.  The format limited line length to something less than 256
bytes (exact length was content dependent).  The lines were split into
groups of up to 30 bytes, 15 bytes content and up to 15 bytes trailing
spaces.  And this was the reason: it was a piss-poor attempt at
efficient storage.  The only way to access it was with a special
library with procedures like EDITREAD and EDITWRITE.  I still have a
number of these files, and there's no easy way to convert them.

Greg
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