4 Dec
2003
4 Dec
'03
10:30 a.m.
On Fri, 5 Dec 2003, Tony Duell wrote:
[1] There's an extra field in each directory entry
(the RT11 system
allows for this) which holds the extact number of bits used in the last
sector of the file.
Bytes, right?
There is no FAT, or anything like it, in the RT11
structure. Each
directory entry stores the start block number and length for each file,
unused space had directory entries too, and they're sorted in ascending
order of blocks. Files must be contiguous.
So, yeah, if you had a 28-blocks file,
and changed the word "foo" to
the word "bar" at byte offset 219 in block 12, then what? Was it
smart enough to just rewrite that block? When extending a file,
did it have to rewrite the entire file to a new location if the
block after the 28th block was already in use?
--f
--
Fred N. van Kempen, DEC (Digital Equipment Corporation) Collector/Archivist
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