Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!killer!pollux!dalsqnt!rpp386!pigs!haugj
From: haugj@pigs.UUCP (Joe Bob Willie)
Newsgroups: comp.sys.ibm.pc
Subject: Re: How can you check that a readable floppy is in a drive?
Summary: is your drive up to speed when you query it???
Message-ID: <223@pigs.UUCP>
Date: 11 Aug 88 21:30:40 GMT
References: <1736@erix.ericsson.se>
Reply-To: haugj@pigs.UUCP (Joe Bob Willie)
Organization: Big "D" Oil and Gas
Lines: 18

In article <1736@erix.ericsson.se> mike@erix.ericsson.se (Mike Williams) writes:
|is in a cerain drive (for example b:). I have tried using
|int 13h with ah=4 to do a verify on a sector on the floppy. This
|always works OK on the second or third attempt. But if the disk
|is not readable and one tries again with a new disk always
|fails on the first new attempt with 'Drive failed to respond' in ah 
|(80H) on return. The next attempt gives 'address mark not found'
|and 'requested sector not found' (06H) in ah and the third attempt
|works.

it may be that your floppy drive has not yet spun up to speed
until the third request is issued.  try sticking a delay in between
the first drive query and the second.  don't forget that physical
hardware is SLOW by comparision to CPU's.
-- 
 jfh@rpp386.uucp	(The Beach Bum at The Big "D" Home for Wayward Hackers)
     "Never attribute to malice what is adequately explained by stupidity"
                -- Hanlon's Razor