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From: oscar@csis.dit.csiro.au (Oscar Bosman)
Newsgroups: comp.sys.apollo
Subject: Problem with sio and mag tape drive
Message-ID: <1991Feb21.000405.25324@csis.dit.csiro.au>
Date: 21 Feb 91 00:04:05 GMT
Organization: CSIRO Division of Information Technology
Lines: 21

I am trying read and write 1/2" magnetic tape using sio_$ calls (DN3010, 
SR10.2) and the Danford controller board (TDI-3010, ver. 120.10.0.3).  
My problem ocurrs when I try to write a file across more than one tape reel.  
After detecting the EOT warning I write two EOF's but the second EOF 
overwrites the last couple of records (1kbytes).  I do this by an ios_$close,
incrementing the file sequence number with a bunch of mts_$ calls, followed 
by an ios_$open and an ios_$close.  Interestingly, the last ios_$open doesn't 
repeat the EOT warning.  Writing two EOF's when there hasn't been an EOT 
warning is OK.  My code is based on the example in _Programming_with_
_Domain/OS_calls_, p 9-15ff.

Has anybody tried to something similar?  Could please point out my silly
mistake.

Thanks in advance.

Oscar.
-- 
Oscar.BOSMAN@csis.dit.csiro.au      phone: +61-6-2750912   fax: +61-6-2571052
Centre for Spatial Information Systems,
CSIRO, Div. Information Technology, Canberra, AUSTRALIA.