[Info-vax] MAX record size in a sequential file

[Steven Schweda]

> [...] Why do some programs seem to update the header to
> reflect the longest record size while others leave it at max?

   I know nothing, but I can imagine a file-reading program
which uses a maximum-record-length value to set a buffer
size.  I can also imagine a file-writing program which does
not care about, or keep track of, the actual maximum record
length in its output file.  In such a situation, I know which
value I'd want the file-writing program to store as the
maximum record length.

   For a file with variable-length records, an update
operation might require completely reading the file to
determine the new maximum record length, so I can easily
imagine not wanting to maintain an accurate
maximum-record-length value for an output file.


> [I don't remember how we managed to get a return with no linefeed
> when overtyping, although of course backspaces would do it].

   In the pre-Selectric era, pushing the carriage back would
do it.  Pushing on the handle did the vertical advance.
Pushing on the end of the platen did not.