*BSD News Article 34351


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Newsgroups: comp.os.386bsd.questions
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From: jmonroy@netcom.com (Jesus Monroy Jr)
Subject: Re: Anyone can explain these warnings ?
Message-ID: <jmonroyCuK7CD.FMt@netcom.com>
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References: <wgalazka.176.2E4221D2@chem.uw.edu.pl> <31ti2u$78h@pdq.coe.montana.edu>
Date: Mon, 15 Aug 1994 04:33:48 GMT
Lines: 55

Nate Williams (nate@bsd.coe.montana.edu) wrote:
: In article <wgalazka.176.2E4221D2@chem.uw.edu.pl>,
: Wojciech Galazka <wgalazka@chem.uw.edu.pl> wrote:

: >Every time during copying distribution sets from high density disketees 
: >from a: I got 
: >"fd0: readl failed ST0 70 <abnmrl seek_cmplt_equ_chek> cyl 0"
: >but the copying process goes  well

: I think this is a 'bug/feature' of the floppy disk driver, but I'm not
: the expert on the floppy driver by any means.
:
	I am an expert on floppy drivers... 

	The ST0 refers to Status register zero (0).

	70  is a hexidecimal representation of the status register.
	The register is a bit oriented boolean state condition
	flip-flop storage. 

	The leading two bits (the MSB bits) indicate 
	the type of completion that it encountered.
	In this case, it encountered an "abnmrl" (abnormal)
	result.

	The next bit indicates the completion of a SEEK command.
	
	The next LSB indicated that an "Equipment Check" failed.
	The logical result is not quite correct english, the 
	reason being is that the FDC chip was designed in JAPAN
	(I think) because most FDC chips follow the NEC version
	which states:
		"If a fault signal is received from the FDD
	(Floppy Disk Drive), or if the Track 0 (zero) Signal
	fails to occur after 77 step Pulses (Recalibration
	Command) then this flag is set"

	In english this means that your drive was probabley sp?)
	on the 78/79/or 80th track when a Recalibration Command
	was issued.  Since your FDC was following the structure 
	of the NEC design you will see this error from time to
	time.

	The fix:  FREEBSD guys look at my code. The problem
		is documented.

	Alternate fix: get a new FDC card... test my premise
			first, of course.

	Good luck.
-- 
Jesus Monroy Jr                                          jmonroy@netcom.com
Zebra Research
/386BSD/device-drivers /fd /qic /clock /documentation
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