X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f X-Trace-PostClient-IP: 68.147.131.211 From: Brian Inglis Newsgroups: comp.os.msdos.djgpp Subject: Re: Read by sector or Read by track more efficient? Organization: Systematic Software Message-ID: References: <354933d6 DOT 0407292314 DOT b48ea86 AT posting DOT google DOT com> X-Newsreader: Forte Agent 1.93/32.576 English (American) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 33 Date: Fri, 30 Jul 2004 10:58:47 GMT NNTP-Posting-Host: 24.71.223.147 X-Complaints-To: abuse AT shaw DOT ca X-Trace: pd7tw3no 1091185127 24.71.223.147 (Fri, 30 Jul 2004 04:58:47 MDT) NNTP-Posting-Date: Fri, 30 Jul 2004 04:58:47 MDT To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com On 30 Jul 2004 00:14:39 -0700 in comp.os.msdos.djgpp, gohyongkwang AT hotmail DOT com (Goh, Yong Kwang) wrote: >Hi. I'm currently using _bios_disk function in a simple program to >explore raw floppy disk content. > >To read an entire floppy disk, afaik, there's two way when calling the >_bios_disk function. > >Method 1 is to read the entire track in a single call by specifying >the number of sectors to read as the number of sectors per track and >to loop thru all the tracks for an entire disk. Drawback is that it's >impossible to identify which sector of the track is bad/unreadable >when the function call fails. > >Method 2 is more fine-grained by having an additional loop that loops >thru all the sector in a track one-by-one, reading in 1 sector per >function call. Appears to be slower but allows the program to identify >which specific sector is bad/unreadable. See other post for speed comparison. When you get a diskette error, you have to reset/recalibrate the drive to clear it, so you might as well read full tracks for speed, then if you get an error, reset/recalibrate, then reread the track by sector to identify the failing sector, reset/recalibrate, try a couple more times to make sure, finish reading the track by sector, then switch back to full track reads. -- Thanks. Take care, Brian Inglis Calgary, Alberta, Canada Brian DOT Inglis AT CSi DOT com (Brian dot Inglis at SystematicSw dot ab dot ca) fake address use address above to reply