Date: Thu, 8 Jun 1995 01:35:32 +0200 (MET DST) From: J Wunsch <j@uriah.heep.sax.de> To: freebsd-hackers@freebsd.org (FreeBSD hackers) Subject: Re: silo overflows Message-ID: <199506072335.BAA13215@uriah.heep.sax.de> In-Reply-To: <9506072244.AA21412@borg.ess.harris.com> from "James Leppek" at Jun 7, 95 06:44:06 pm
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As James Leppek wrote: > > The floppy is not on the adaptec, only a little used drive and an > exabyte tape drive for backups (which were not being dome). > > Adaptec's 154X controllers are the most `famous' bus hogs. They do > > also cause all sort of troubles with floppy DMA operations ... Actually, it's totally unimportant whether you're using Adaptec's floppy controller or not. The problem is that the AHA-154X SCSI(!) controllers tend to hog the bus for too long, and an HD floppy controller needs to be serviced once each 16 µs. If this time expires, the FDC will abort the operation on the currently transferred sector. One could easily argue that the current fd driver handles this condit- ion very ungracefully (wasting a whole revolution to retransfer the sector in question), but i've got more important things on the plate regarding the floppy controller than improving support for braindead Adaptecs. (Once i've been replacing my Adaptec by an Bt 742A, the problem magically disappeared.) (No offense intended. Apologies to everybody who's thinking this would sound too rude. :) -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ Never trust an operating system you don't have sources for. ;-)
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