Date: Mon, 8 May 2000 13:41:42 -0700 From: "David O'Brien" <obrien@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/share/man/man4 sa.4 Message-ID: <20000508134142.A52499@dragon.nuxi.com>
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-- Forwarded message from Kirk McKusick <mckusick@flamingo.McKusick.COM> -- Subject: traditional BSD tape device names Hello Dr. McKusick, Many of the FreeBSD committers are arguing over the meaning of tape device names. Some say "nr" as in `nrst0' stands for "no-rewind". Others say "n" means no-rewind, and "r" means raw. Thus the first group says `rst0' has rewind semantics due to the "r" (as oppose to it being a rewind semantics due to a missing "n"). Would you be able to set us straight? -- -- David (obrien@NUXI.com) I am probably the wrong person to ask to set anybody straight :-) In early BSD, the block tape device was mt0, the character (aka raw) tape device was rmt0, and the non-rewinding tape device was nrmt0. The block device tape became history in the early 1980's, so we were left with only the character version. On 4.4BSD there were four entries for tape drives: rst0 which was hard linked to rmt0 and nrst0 which was hard linked to nrmt0. The first two being the rewinding version, the latter two being the non-rewinding version. The `mt' name historically referred to the 9-track `magnetic tape'. The `st' name came into existence with the cartridge `streaming tape' drives. Once 9-track tapes disappeared, the two names were linked to provide backward compatibility for programs (like dump and tar) that defaulted to rmt0. Kirk McKusick ----- End forwarded message ----- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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