Path: utzoo!mnetor!uunet!ncc!alberta!att!ihnp4!chinet!les
From: les@chinet.UUCP (Leslie Mikesell)
Newsgroups: comp.sys.att
Subject: Re: Accessing the ctc on a 3B2/400 from a program ?
Message-ID: <5127@chinet.UUCP>
Date: 7 May 88 22:09:58 GMT
References: <744@ambush.UUCP>
Reply-To: les@chinet.UUCP (Leslie Mikesell)
Organization: Chinet - Public Access Unix
Lines: 21
Keywords: ctc 3B2/400

In article <744@ambush.UUCP> storm@ambush.UUCP (Kim F. Storm) writes:
>
>We have to port a program to backup large files (and disks) on the
>23 Mbyte cartridge tape on the 3b2/400.
>
>There is no problems in moving the code (isn't C+UNIX wonderful),
>but we cannot get any good performance out of the tape drive, because
>we cannot make it stream.
>
The "afio" program posted a while back included support for the 3B2
streaming tape by doing the following:

  the flags to open() are  O_RDWR | O_CTSPECIAL

  after the open, ioctl(fd,STREAMON) is used to enable streaming

  streaming mode writes (and reads) must multiples of a certain size.
  Afio uses 31 * 512, and limits the total output to 1469 such blocks instead
  of watching for EOT from the device.

  Les Mikesell