X-Authentication-Warning: delorie.com: mailnull set sender to djgpp-bounces using -f From: "Tim Nicholson" Newsgroups: comp.os.msdos.djgpp Subject: Protected Mode disk access Date: Mon, 21 Jan 2002 17:45:50 -0000 Message-ID: <1011635483.28296.0.nnrp-08.c1ed6b28@news.demon.co.uk> NNTP-Posting-Host: skyforce.demon.co.uk X-NNTP-Posting-Host: skyforce.demon.co.uk:193.237.107.40 X-Trace: news.demon.co.uk 1011635483 nnrp-08:28296 NO-IDENT skyforce.demon.co.uk:193.237.107.40 X-Complaints-To: abuse AT demon DOT net X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Lines: 29 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Am I correct in thinking the DJGPP switches from protected mode to real mode to access the HDD and transfers data in 64K blocks (variable) via the DPMI to and from DOS? Is it not possible to access the HDD directly in protected mode via a FAT32 Library? - Does such a thing exist? and would it speed up disk I/O where reasonable quantities (several MB) of data was been transferred to and from the drive? The reason for asking is that disk I/O seems much faster under Windows 98/ME etc. and I am guessing this is partly because the whole thing is happening in protected mode. Does DOS (the one shipped with Win98) utilise the full capabilities of the drive (i.e.. UDMA100 etc)? Sorry for so many questions but my application is very disk intensive and despite using smartdrive and my own cache routines to ensure that I only load things if I don't already have them, I can't help thinking it should be going much faster! I can't use Windows or Linux because the code must be deterministic to meet certification requirments, besides, I like DOS! Regards Tim Nicholson