From: Jason Green Newsgroups: comp.os.msdos.djgpp,alt.os.development Subject: Re: Help wanted (was Re: 18-sector limit with biosdisk()) Date: Sat, 24 Feb 2001 23:39:46 +0000 Organization: Customer of Energis Squared Lines: 43 Message-ID: <9kgg9tocovqrgq5mcldu1fbmfc8uf9vknh@4ax.com> References: <3a980fec$0$30002$6d6c75b AT news DOT execpc DOT com> NNTP-Posting-Host: modem-208.alaska.dialup.pol.co.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: newsg4.svr.pol.co.uk 983057958 15299 62.137.53.208 (24 Feb 2001 23:39:18 GMT) NNTP-Posting-Date: 24 Feb 2001 23:39:18 GMT X-Complaints-To: abuse AT theplanet DOT net X-Newsreader: Forte Agent 1.7/32.534 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Firstly, the problem I had originally with booting Linux kernel from an over-sized floppy is (just) now solved. It seems that increasing sectors and/or tracks does not cause a problem, but multiple sector size (mss) does not make the kernel happy when booting. Sorry if I led you to chase this unecessarily - although I would still believe what Tom said about some BIOSes being buggy. NoEmailAds AT execpc DOT com (Chris Giese) wrote: > >> Otherwise, I could write a small test program to check if the BIOS > >> really does limit reads to 18 sectors. > > > >That might also be a good idea. > > OK, here it is: > http://www.execpc.com/~geezer/temp/ftest.c > http://www.execpc.com/~geezer/temp/ftest.exe > > Please download it and try it. If it reports that your BIOS > limits INT 13h reads to 18 sectors, let me know. No problem here, but I no longer suspect this BIOS as buggy. This is the output from ftest: This program tests if BIOS function INT 13h AH=02 limits multi-sector reads to 18 sectors. You need an "oversized" FAT12- (DOS-)formatted floppy, with 19-21 sectors per track Reading sector 0 of floppy disk... Checking for FAT filesystem... Boot sector says 21 sectors per track Patching floppy parameter table (FPT)... Current FPT at address 0:522 Current maximum sectors-per-track value in the FPT is 18 New FPT at address 1211:0 New maximum sectors-per-track value in the FPT is 96 Reading 21 sectors from track 0, head 0... Restoring old FPT... Success. The INT 13h function in your BIOS does not appear to restrict reads to 18 sectors