swilson%thetone@Sun.COM (Scott Wilson) (10/14/88)
In article <635@ardent.UUCP> kmw@ardent.UUCP (Ken Wallich) writes: >In article <72886@sun.uucp> swilson@sun.UUCP (Scott Wilson) writes: >>>...256 Megabyte Optical Disk, making possible this new storage technology >>>The Optical Disk combines the vast storage capacities, removability >>>and reliability of laser technology with the fast access and full >>>read/write/erase capabilities of Winchester (magnetic) technology. >> >>Hmm, this looks suspicious to me. Note that the the terms "vast >>storage capacities", "removability", and "reliability" are used to >>describe laser technology while "full read/write/erase" capabilites >>are associated with Winchester (magnetic) technology. Does this mean >>that it is nothing more than CD-ROM and an old-fashioned hard disk >>packaged together? > >I find it odd that you interpret the phrase this way. I see only one device >mentioned, a 256 Meg Optical Disc, it's features are that it has >lots of storage on a reliable, removable optical disc, which is also >fast and allows you to read/write/erase, just like the 'ol magnetic discs >everyone else is so fond of, and that everyone currently associates with >read/write/erase. Well, I never thought of it that way. Maybe your right. I guess it all depends on how you look at it. For example, leaving out a few words you could have either: "The Optical Disk combines ... laser technology with ... Winchester (magnetic) technology." or: "The Optical Disk combines removability and reliability and ... read/write/erase capabilities ...." So either it's a hybrid of the two technologies or its just optical technology that has the same features as magnetic technology. Isn't English fun? -- Scott Wilson arpa: swilson@sun.com Sun Microsystems uucp: ...!sun!swilson Mt. View, CA "And the fool loves war, and the gentle die." -The Call
hankd@pur-ee.UUCP (Hank Dietz) (10/14/88)
In article <73003@sun.uucp>, swilson%thetone@Sun.COM (Scott Wilson) writes: > In article <635@ardent.UUCP> kmw@ardent.UUCP (Ken Wallich) writes: > >In article <72886@sun.uucp> swilson@sun.UUCP (Scott Wilson) writes: [Much stuff about the optical disk...] Certainly, it is possible to make a randomly read/write/modify optical disk; isn't that what Tandy did just a short while ago? The things that bug me are: (1) Less than 300M of storage... that's less than an audio CD. Does this imply that the format is some brand new magic thing that nobody else will be using? (2) $50 each? It should be more like $15 each.... I wonder why it isn't? (3) One disk is the minimum you can run with, and we all know it's stupid to try that, but it sure makes the system price seem nicer.... I'd say that the one-disk system is a marketing hack comparable to selling cars with 3 tires and making the fourth one optional: who's not gonna buy the extra tire? Most of us will even buy a spare.... -hankd
ken@gatech.edu (Ken Seefried iii) (10/15/88)
In article <9480@pur-ee.UUCP> hankd@pur-ee.UUCP (Hank Dietz) writes: >(1) Less than 300M of storage... that's less than an audio CD. Does this > imply that the format is some brand new magic thing that nobody else > will be using? The unfortunate thing about optical disks is at the single bit level, they are pretty unreliable. Typically, 20-30% of the disk is used for error detection and correction. I understand that the NeXT machine uses about 30%. This wastes a lot of space, but make the disk very relaible. More than likely, no one else is doing quite the same thing. >(2) $50 each? It should be more like $15 each.... I wonder why it isn't? Not true. The optical media for most 5 1/4" WORM drives (eg ISI, Optotech, etc.) runs over $100 dollars, and often lists for $200. $50 is pretty reasonable by comparison... >(3) One disk is the minimum you can run with, and we all know it's stupid > to try that, but it sure makes the system price seem nicer.... I'd > say that the one-disk system is a marketing hack comparable to selling > cars with 3 tires and making the fourth one optional: who's not gonna > buy the extra tire? Most of us will even buy a spare.... > Perhaps, perhaps not. Remeber, an optical disk is not subject to head crashes and other magnetic disk problems, so you don't have to worry about the power going out and thrashing your data. That is not to say that I won't buy a second drive, but it will be for speed, not data reliability... ken seefried iii ...!{akgua, allegra, amd, harpo, hplabs, ken@gatech.edu inhp4, masscomp, rlgvax, sb1, uf-cgrl, ccastks@gitvm1.bitnet unmvax, ut-ngp, ut-sally}!gatech!ken
wetter@tybalt.caltech.edu (Pierce T. Wetter) (10/15/88)
>(2) $50 each? It should be more like $15 each.... I wonder why it isn't?
When HP first started using 3.5" micro floppys they were $50 a box for 10.
Pierce
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wetter@tybalt.caltech.edu pwetter@caltech.bitnet pwetter@caltech.edu
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Weird theory #48: I'm going to graduate in June.
Send Job Offers to: 1-57 Fleming. Pasadena Ca. 91126elg@killer.DALLAS.TX.US (Eric Green) (10/15/88)
in article <73003@sun.uucp>, swilson%thetone@Sun.COM (Scott Wilson) says: $ In article <635@ardent.UUCP> kmw@ardent.UUCP (Ken Wallich) writes: $>In article <72886@sun.uucp> swilson@sun.UUCP (Scott Wilson) writes: $ Well, I never thought of it that way. Maybe your right. I guess it all $ depends on how you look at it. For example, leaving out a few words you $ could have either: $ $ "The Optical Disk combines ... laser technology with ... Winchester $ (magnetic) technology." $ $ or: $ $ "The Optical Disk combines removability and reliability and ... $ read/write/erase capabilities ...." $ $ So either it's a hybrid of the two technologies or its just optical $ technology that has the same features as magnetic technology. Isn't $ English fun? Actually, the new read/write/erase optical drives DO use magnetic technology -- EE Times had a writeup on them a while back, and apparently they use weird interactions between laser light and certain magnetic materials (interference effects?). Alas, a quick glance at my bookshelf doesn't turn up that copy, so I can't give any real details -- but surely someone around Sun could dig it up for you, if you're truly mystified? -- Eric Lee Green ..!{ames,decwrl,mit-eddie,osu-cis}!killer!elg Snail Mail P.O. Box 92191 Lafayette, LA 70509 Software does not happen in a vacuum. Software designers need to know something about hardware, too, despite what the academics tell you.
spolsky-joel@CS.YALE.EDU (Joel Spolsky) (10/15/88)
in article <73003@sun.uucp>, swilson%thetone@Sun.COM (Scott Wilson) says: | | "The Optical Disk combines ... laser technology with ... Winchester | (magnetic) technology." | | or: | | "The Optical Disk combines removability and reliability and ... | read/write/erase capabilities ...." | | So either it's a hybrid of the two technologies or its just optical | technology that has the same features as magnetic technology. Isn't | English fun? There's a detailed description of how this drive works in the November Byte magazine. Sorry, I can't post it, but I think it's on BIX. +----------------+---------------------------------------------------+ | Joel Spolsky | bitnet: spolsky@yalecs uucp: ...!yale!spolsky | | | arpa: spolsky@yale.edu voicenet: 203-436-1483 | +----------------+---------------------------------------------------+ #include <disclaimer.h>
lyang%scherzo@Sun.COM (Larry Yang) (10/18/88)
In article <9480@pur-ee.UUCP> hankd@pur-ee.UUCP (Hank Dietz) writes: >Certainly, it is possible to make a randomly read/write/modify optical disk; >isn't that what Tandy did just a short while ago? The things that bug me are: > >(1) Less than 300M of storage... that's less than an audio CD. Does this > imply that the format is some brand new magic thing that nobody else > will be using? An audio CD has as its "format" basically one, long serial spiral (not unlike its vinyl counterpart). In computer applications, I believe the disks are usually formatted into wedges (sectors), not unlike its magnetic counterpart. Thus, along with the ECC overhead, there is the overhead for formating the sectors, labeling the sectors, etc. But wait... is the disk the same physical size as the audio CD? >(2) $50 each? It should be more like $15 each.... I wonder why it isn't? My guess is that the price will come down with time. --Larry Yang [lyang@sun.com,{backbone}!sun!lyang]| A REAL _|> /\ | _ _ _ Sun Microsystems, Inc., Mountain View, CA | signature | | | / \ | \ / \ | <|_/ \_| \_/\| |_\_| | _/ _/
cory@gloom.UUCP (Cory Kempf) (10/20/88)
In article <73226@sun.uucp>, lyang%scherzo@Sun.COM (Larry Yang) writes: > An audio CD has as its "format" basically one, long serial spiral > (not unlike its vinyl counterpart). In computer applications, I believe > the disks are usually formatted into wedges (sectors), not unlike its > magnetic counterpart. Thus, along with the ECC overhead, there is the > overhead for formating the sectors, labeling the sectors, etc. A data CD (at least in the standards that I have used) is formatted in a LONG spiral. the spiral is broken down into several blocks, each of which "looks" like it is 2k. In reality, they use some error correction code (ECC) that causes 8 bits to use up 14 bits of space. A CD-ROM holds about 660Mb of data after ECC, or on the order of 1 Gb without the ECC. Unfortunately (at least from what I have heard), the Audio CD's (and CD-ROM's are not compatable with the WORMs or WMRM drives. The Audio CD/CD-ROM work on a laser reflection off of pits in the substrate of the disc. (NB: when refering to CD's, disc is correct, not disk.) -- Cory Kempf UUCP: {decvax, bu-cs}!encore!gloom!cory revised reality... available at a dealer near you.