On Wed, 18 Dec 2002 19:02:41 -0400, Glenn McCorkle wrote:

> clipped from  'mem /d' for v4.00.1111

>                    464    (0K)               Block device tables

> Clipped from 'mem /d' for v4.00.950

>                    304    (0K)               Block device tables

> Now... to diagnose exactly why that is. And exactly what is contained
> in that extra 160 bytes. ;-)

This is "drive data table". I guess that you have three logical
drives (A:, B:, C:) in your machine, because there is 100 bytes
per drive in DOS 4.0..7.0, and it's rounded up to the next
multiply of 16 bytes (304 in your case); see RBIL Table 02603.
Unfortunately, DOS 7.10 format of drive data table isn't yet
documented in RBIL. It seems like 150 bytes per drive is used
(in the machine I tested under Win95(.1111), 608 bytes for logical
drives A:-D:).

The reason for the larger table is obvious: DOS 7.10 can use
32-bit cluster numbers and LBA disk addresses, so it needs
more space to hold them.

I'm not sure what format FreeDOS uses; in fact, FreeDOS is
-- in its current stage of development -- some kind of mixture
of DOS versions ;-)

Michal

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