hgm@ncsuvx.ncsu.edu (Hal G. Meeks) (06/08/89)
This was relayed to me from a friend; I know nothing else about the drives. I will be watching this closely; my 40 meg HD is almost full, and backups are getting to be a real pain. Check out the projected retail cost. ------------------------------------- From Amiga Sharewarer's BBS HQ 313-473-2020: The 1989 March 13 issue of INFOWORD on page 30 has an article titled "PANASONIC INDUSTRIAL ANNOUNCES LARGE-CAPACITY FLOPPY DISK DRIVE". The article written by Patricia Pane states the following: The Memory Systems Division of Panasonic Industrial Co. recently announced a disk drive that will put 11 megabytes of data on a newly developed 3.5 inch metal floppy disk. The large capacity floppy disk drive, called the 3511, is equipped with an embedded SCSI controller and encoder with a micro-stepping motor, and has a self-formatting function to initialize the media, according to the company. The 3511 large-capacity floppy disk drive is also read-only compatible with conventional 1-megabyte and 2-megabyte 3.5 inch disks, according to Panasonic Industrial. The magnetic media, which has an unformatted capacity of 16 megabytes, has a formatted capacity of 11 megabytes and a linear recording density of 35,000 bits per inch with 640 tracks on each side, according to the company. The metal disk and two recording heads increase the linear recording density, and a micor-stepping motor with an encoder allows high-speed access and high-precision tracking of plus or minus 2 micrometers. The 3511's average access time is less than 60 milliseconds and track-to-tack time is less than 10 milliseconds, according to Panasonic Industrial. The drive's data transfer rate is 2 megabits per second, according to the company. Evaluation units of the 3511 floppy disk drive will be available in the second quarter, with production quantities scheduled for July. The 3511 drive will list for $250. Panasonic Industrial Co. Memory Systems Division 1600 McCandless Drive Milpitas, CA 95035 (408) 262-2200 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Hal Meeks "Things have changed, things will change, netoprhm@ncsuvm.bitnet and it breaks down." hgm@ncsuvx.ncsu.edu The Past Revisted 4/88 -- --------------- hgm@ncsuvx.ncsu.edu "Things have changed, things will change, netoprhm@ncsuvm.bitnet and it breaks down." The Past Revisited 4/88
FelineGrace@cup.portal.com (Dana B Bourgeois) (06/11/89)
Re: the Panasonic 3511 drives... So, is this handled as a hard drive or a floppy? It is SCSI so I guess the Trackdisk device wouldn't handle it but then you'd need another new driver for it, yes? Wouldn't this unit make a good candidate for that new File System being designed by (Oh lord, I need virtual memory so I can store everyone's name in it!), uh, was it devon? C'mon, surely you remember all the talk about the File System that would write whole tracks instead of sectors. Bet more than 11 Meg could be put onto each disk. Dana "and stop calling me Shirly". With apologies to 'Airplane'.
mcp@ziebmef.uucp (Marc Plumb) (06/14/89)
In article <19334@cup.portal.com> FelineGrace@cup.portal.com (Dana B Bourgeois) writes: >Wouldn't this unit make a good candidate for >that new File System being designed by (Oh lord, I need virtual memory >so I can store everyone's name in it!), uh, was it devon? C'mon, >surely you remember all the talk about the File System that would write >whole tracks instead of sectors. Bet more than 11 Meg could be put >onto each disk. I think it was me (name: Colin), and I'm working on it.. slowly. If something is SCSI, then it's not amenable to the techniques I use, which know that the device driver copies data into buffers a track at a time. Since the buffering algorithm is hidden on the other end of the SCSI bus, I have to live with whatever the firmware authors designed. All the expanded capacity comes from deleting the 6-word headers on each block (okay, so I have 6 *bytes* per *track*, sue me), which the FFS does, and using the header label area (27.5K bonus). I also reduce the size of file headers by a factor of 10, so you can fit 40,000 or so empty files with single-letter names and no comments on a floppy, or waste less than a K on administrivia for a single floppy-sized file. On a SCSI device, I'd only gain the last point over FFS. Also, a lot of the tradeoffs are based on the 27K/sec read speed of the hardware relative to the cost of blitting a track's worth of data around. What do you want to bet the 10 Meg floppies are faster, changing all the tradeoffs? I do a *lot* of speculative data copying, knowing that if it saves me a fraction of a seek (average) later, it's worth it. Not true for disks with faster seeks and more data to copy around... And, the numbers of bits I have assigned to some things become inadequate around 1.5 Meg. Since floppies are always full, I tried hard to save space. For larger drives, my administrivia would dramatically increase in size. I have a few ideas for a hard drive file system - performance goals include 1MB/sec DiskPerf on a 90% full volume and crashproofness for the file system. (Question: two adjacent sectors is all a modern drive will usually trash in a glitch, but head crashes and things can take out whole surfaces or cylinders. Being robust requires writing two copies of all vital information sufficiently far apart that they will not both be erased by a single glitch, so greater resistance can be purchased at the price of more seeks. How big an error would people like to be able to cope with? The ultimate is twin disks, but you can come close on one.) But that's for some *year* or other... If anyone gets impatient, please write your own! -- -Colin Plumb
FelineGrace@cup.portal.com (Dana B Bourgeois) (06/19/89)
Colin, thank you for the explanation. I guess Quad density drives would be a possibility for your project but nothing with more capacity. Sorry for not getting your name right. The guilty party is being lashed with the wet noodle as you read this. Dana "Ouch!! that *hurts*!!" Bourgeois