[Info-vax] Looking for suggestions for new $GETDVI item codes

[Simon Clubley]

On 2015-01-15, JF Mezei <jfmezei.spamnot at vaxination.ca> wrote:
> On 15-01-15 11:51, Stephen Hoffman wrote:
>
>> disruptive, no matter how those changes are rolled out.  Modern disk 
>> blocks are now 4096 bytes, and there's more than a little code around 
>> that assumes 512-byte blocks, and there's more than a little code that 
>> assumes that disk sizes will fit in longwords,
>
>
> Would sector/block size be a driver level issue that is more or less
> irrelevant to applications ?
>

Not just a driver issue, JF.

For example, the filesystem needs to know the location of files by
LBA. You can work around that by using blocklets, but you can't use
the bigger disks in that case unless you extend the size of the fields
for the LBAs.

Likewise, locking includes a block number component and you would have
to translate that into blocklets unless you supported 4096 byte blocks
above the driver level.

> If I do a "seek" in an application, I am not too concerned with which
> sector it is in as I give a relative offset from start of file.
>

If that's a 32-bit seek, then 4096 byte blocks don't buy you anything.

BTW, I've believed for a good number of years now, that integers should
be unsigned by default and if you want a signed integer, you should have
to ask for it.

Make signed integers the default and people will use them even when it
doesn't accurately model the data which the program is manipulating.
The end results are all the artificial limits and security issues we see.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world