Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request From: tardis!jms@tymix.tymnet.com (Joe Smith) Newsgroups: comp.sys.sun Subject: Re: cartridge tape designators Message-ID: <705@brazos.Rice.edu> Date: 31 Jul 89 19:50:10 GMT Sender: root@rice.edu Organization: Sun-Spots Lines: 41 Keywords: Hardware Approved: Sun-Spots@rice.edu X-Sun-Spots-Digest: Volume 8, Issue 91, message 3 of 16 In article <114@brazos.Rice.edu> stiatl!meo@gatech.edu (Miles O'Neal) writes: >X-Sun-Spots-Digest: Volume 8, Issue 70, message 1 of 15 > >In article <4107@kalliope.rice.edu> eli@chipcom.chipcom.com writes: >| X-Sun-Spots-Digest: Volume 8, Issue 49, message 1 of 11 >| >| what is the difference between /dev/rst0 and /dev/rst8 >| and likewise between /dev/nrst0 and /dev/nrst8 > >The difference is the tape format. I don't remember the exact definitions, >but basically, the 0 devices are for 45MB tape formats, and the 8 devices >use the 60MB formats. They aren't interchangeable. > >Miles I, too, would like to know the difference between rst0 and rst8 on 1/4 inch tape. The only references I have found are on page 84 of the "Network and System Administration" manual, part 800-1733-10, Rev A, May 1988. rst0 = QIC-11, 9 tracks, 45 Mbytes on 450 ft, 60 Mbytes on 600 ft tape rst8 = QIC-24, 9 tracks, 45 Mbytes on 450 ft, 60 Mbytes on 600 ft tape This implies that the amount of storage depends only on the length of tape and not whether you specify /dev/rst0 vs /dev/rst8. I have been told that the tape drive always stores 512 bytes per tape block. There is a flag bit to say whether more data follows, a count of valid bytes, and a checksum for the block. Is it true that QIC-11 and QIC-24 store the same amount of data on the tape, and just have different standards for encoding the length and checksum? Which format is recommended for doing dumps? Which format should be used for interchanging data with other systems? In other words: when should I use rst0 and when should I use rst8? Joe Smith (408)922-6220 | SMTP: JMS@F74.TYMNET.COM or jms@tymix.tymnet.com McDonnell Douglas FSCO | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms PO Box 49019, MS-D21 | PDP-10 support: My car's license plate is "POPJ P," San Jose, CA 95161-9019 | narrator.device: "I didn't say that, my Amiga did!"