/V (Was: VCF Ban, Vector Graphic cards, Wright card punch,

Fred Cisin cisin at xenosoft.com
Wed Apr 29 11:36:44 CDT 2015

On Wed, 29 Apr 2015, Mike Stein wrote:
> incidentally, you may also be surprised as I was that the DOS /v verify 
> option does not in fact verify that a copy was correct:
> http://www.vintage-computer.com/vcforum/showthread.php?45454-5162-serial-port-9600bps-interlink-use-xcopy-with-v

"/V" is not a "DOS" option.  It is an option internal to
many DOS programs, and maybe a few "internal" commands.
As such, EACH implementation of it is free to make its own
interpretation of what it might or SHOULD mean.

Although many people assume that it would mean confirming
that a copy is truly a duplicate of the original, its actual
use is usually merely to verify that the copy remains readable -
that the CRC "checksum" of each sector matches the CRC "checksum"
recorded in the header of that sector.
(as derived from its original use in the FORMAT program, where
the NEC "VERIFY" command is used to confirm readability of sector(s).)

Accordingly, many people assert that its behavior not matching
their assumption constitutes a "bug".

Grumpy Ol' Fred     		cisin at xenosoft.com

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