On Thu, 19 Dec 2002 17:22:47 +0100, Michal H. Tyc wrote: > 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 Now, we're making some progress. IO.SYS writes that infomation into memory at boot-up. Have a look at the part of the SRC code for wwwman.exe which then reads the info from there. ---- drvtypes.cpp attached --- -- Glenn http://arachne.cz/ http://www.delorie.com/listserv/mime/ http://www.angelfire.com/id/glenndoom/download.htm http://www.thispagecannotbedisplayed.com/
drvtypes.cpp
Description: File "drvtypes.cpp" (type application/octet-stream, size 3 KB)
