AWCTTYPA@UIAMVS.BITNET ("David A. Lyons") (06/22/88)
>Date: Tue, 21 Jun 88 08:26:31 EST >From: Murph Sewall <SEWALL%UCONNVM.BITNET@mitvma.mit.edu> I wrote: >It gets less and less reasonable to keep using DOS 3.3. CD-ROMs would >be ridiculous, for example, addressed 400K at a time. And Murph Sewall wrote: >True, but 32Mbytes at a time may look just as silly on a 1+ gigabyte >device (I know ProDOS can be modified to handle it -- GS OS again? -- >but I couldn't pass-on the thought 'cause I'm not so sure from what >I've read that DOS 3.3 couldn't have been modified as well <too many >other problems to make that I worthwhile approach, no doubt>). ProDOS 16/GSOS should be able to handle very large devices...since there are 4 bytes reserved in the parameter lists for things like file positions and number of blocks, that should hold us for a while. ProDOS could be modified to deal with larger volumes, as long as we stay at the FILE level and not the block level. For that matter, MAYBE DOS 3.3 could be, too--but then there would be no hierarchical structure, and it would still be pretty silly to have CD-ROMs with no directories. > [...] Unfortunately, streaming >backups simply reproduce recorded sectors; so if the platter is replaced >chances are something important (like part of the FAT) is recorded on >what were good but have become bad sectors. Ugh! Sounds like a silly approach to backup to me! >The newer, file-by-file, >technology solves the problem, but they cost a bunch more too (there's >a neat device called "The Fat Boy" described in this week's InfoWorld -- >its a 1.2 gigabyte, file-by-file tape backup that uses standard Video >8 cassettes and transfers at 15 Mbytes per minute). Gee...file-by-file backup isn't a new technology. I used Davex's "update" command to copy changed files onto 3.5" backup disks. My backup disks will be useful if my hard drive dies, unlike a backup tape with no hard drive to restore it to! >ARPA: sewall%uconnvm.bitnet@mitvma.mit.edu Murphy A. Sewall >BITNET: SEWALL@UCONNVM School of Business Admin. >UUCP: [rutgers psuvax1 ucbvax & in Europe - mcvax] Univ. of Connecticut > !UCONNVM.BITNET!SEWALL
SEWALL@UCONNVM.BITNET (Murph Sewall) (06/23/88)
>ProDOS could be modified to deal with larger volumes, as long as we >stay at the FILE level and not the block level. For that matter, MAYBE >DOS 3.3 could be, too--but then there would be no hierarchical structure, >and it would still be pretty silly to have CD-ROMs with no directories. Agreed. As long as your thinking about whacking away at DOS 3.3, think about adding heiarchcal files too :-) If IBM could add sub-directories to a DOS that didn't start out with them, why not Apple? Well, not to bother over it; we've got ProDOS and it's got lots of good features and won't go away... On to GS OS !!!! >> [...] Unfortunately, streaming >>backups simply reproduce recorded sectors; so if the platter is replaced >>chances are something important (like part of the FAT) is recorded on >>what were good but have become bad sectors. > >Ugh! Sounds like a silly approach to backup to me! Not really; just economics. When hard drives first became popular, floppys held at most 360K - that's about 30 floppys to back up a 10M hard drive. Soooo.... use a tape back up, BUT the cost of a tape drive that (mechanically) starts at stops at file beginnings and ends (necessary if you expect to recover selected files from a sequential medium) is beaucoup more costly than a simple (nonstop) streaming system. >Gee...file-by-file backup isn't a new technology. I used Davex's >"update" command to copy changed files onto 3.5" backup disks. My >backup disks will be useful if my hard drive dies, unlike a backup >tape with no hard drive to restore it to! All true, but 1) you're backing up to floppys. Have you noticed that a PS/2 80-311 has a hard disk of more than 300 Mbytes? Assuming you REALLY need that much storage, you may find it just as much of a problem backing up onto 1.44 Mbyte floppys as backing up that puny 10Mbyte drive onto 360K floppys ever was. Start-stop tape drives aren't new either, but have you priced one? Shoot three years ago when I started asking vendors at trade shows about a 1600 bpi 9trk drive capable of dealing with 2400 foot reels, they all looked at me like I'd just arrived from the outer planets. Doesn't seem so silly any more does it? Still, it will be nice when someone manufactures in sufficient quantity to get the price down to less that that of a Toyota :-) --------------------- Disclaimer: --- My employer isn't responsible for my mistakes AND vice-versa! (subject to change without notice; void where prohibited) ARPA: sewall%uconnvm.bitnet@mitvma.mit.edu Murphy A. Sewall BITNET: SEWALL@UCONNVM School of Business Admin. UUCP: {rutgers psuvax1 ucbvax & in Europe - mcvax} Univ. of Connecticut !UCONNVM.BITNET!SEWALL "It might help if we ran the MBA's out of Washington." - Adm Grace Hopper
fredc@pro-citadel.cts.COM (Fred Condo) (06/24/88)
sewall@uconnvm.bitnet (Murphy A Sewall) writes: >Start-stop tape drives aren't new either, but have you priced one? >Shoot three years ago when I started asking vendors at trade shows about >a 1600 bpi 9trk drive capable of dealing with 2400 foot reels, they >all looked at me like I'd just arrived from the outer planets. Doesn't >seem so silly any more does it? Still, it will be nice when someone >manufactures in sufficient quantity to get the price down to less that >that of a Toyota :-) I think you've been hanging around mainframes too long, Murphy :-). I regularly back up our Mac drives using a nifty start-stop tape drive from CMS. It uses 60-MB TEAC tapes that come in a slightly modified cassette shell (looks just like an audiocassette). The whole thing sells for about $800, substantially less than any Toyota. Tapes are about $20 apiece, and you can do both global and incremental file-by-file backups and restores. It also allows mirror backups, but why do that? It's actually slower than file-by-file.... No, I don't know if it works on an Apple //. ==Fred Condo = SysAdmin of Pro-Citadel = 818/339-4704 | Secular humanism: UUCP: crash!pnet01!pro-nsfmat!pro-la!pro-citadel!fredc | it stands to reason. INET: fredc@pro-citadel.cts.com || Paper: PO Box 3812, San Dimas, CA 91773