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