dave@sdeggo.UUCP (04/22/87)
I see that IBM is "introducing" a WORM optical disk. According to the ad, capacity is 200M. Looks like a neat toy. Does anyone know if it's available yet, what the price is and if it's compatible with the PC? -- David L. Smith sdcsvax!sdamos!sdeggo!dave, ihnp4!jack!man!sdeggo!dave, hp-sdd!crash!sdeggo!dave sdeggo!dave@sdamos.ucsd.edu "A clean desk is the work of a sick mind"
johnl@ima.UUCP (04/23/87)
In article <39@sdeggo.UUCP> dave@sdeggo.UUCP (David L. Smith) writes: >I see that IBM is "introducing" a WORM optical disk. According to the ad, >capacity is 200M. Looks like a neat toy. Does anyone know if it's >available yet, what the price is and if it's compatible with the PC? I looked at it at the opening extravaganza in Miami. There is a controller for the existing PC bus -- there has to be because the PS/2 30 has the old bus. It's expensive, though. The list price is $2950. Cartridges are $65 apiece. It's supposed to be available "soon." I'm surprised that nobody has asked yet how they got DOS to talk to a 200MB disk, since DOS 3.3 does not change the 32MB limit for a disk volume. I asked, and it turns out that the driver for the WORM disk hooks into DOS as a network driver, not a disk driver. It makes sense -- DOS can hardly rewrite its FATs on a write-once disk. The driver is optimized for writing whole files, but will do the necessary backflips to allow you to rewrite files in pieces. It remembers everything ever put on the disk, since it's WORM, and there is a utility to go back to a superseded version of a file. -- John R. Levine, Javelin Software Corp., Cambridge MA +1 617 494 1400 { ihnp4 | decvax | cbosgd | harvard | yale }!ima!johnl, Levine@YALE.something Where is Richard Nixon now that we need him?
paul@devon.UUCP (04/24/87)
In article <39@sdeggo.UUCP> dave@sdeggo.UUCP (David L. Smith) writes: > I see that IBM is "introducing" a WORM optical disk. According to the ad, > capacity is 200M. Looks like a neat toy. Does anyone know if it's > available yet, what the price is and if it's compatible with the PC? Before you get too excited about this, read the specs on this "new" product. The data transfer rate is 2.5 megabits/second (despite the fact that it's using the SCSI interface, instead of ST406/412). This is exactly 1/2 the rate of most PC-type winchester drivers. Also, the average access time is 230ms (that's _n_o_t a typo!). My "not-very-fast" Seagate ST-4051 drives are 39ms. The point is, the WORM drive may hold a lot of data, but don't expect to get at it very fast. :-) - paul -- Paul Sutcliffe, Jr. UUCP: paul@devon.UUCP -or- {seismo,ihnp4,allegra,rutgers}!cbmvax!devon!paul "I love work. I could sit and watch people do it all day!"