throop@hilbert.UUCP (Henry Throop) (12/09/90)
Maybe this has been discussed before, but I don't remember seeing it. Does anyone know what the format of a 1.44 MB floppy is based on? Is it the same as a 720K (IBM) 3.5, but just with twice the number of tracks, and thus a constant angular velocity? Or is is some variant on the 800K formatting? Are Mac and IBM 1.44 disks readable (sector-wise) by the same drives? Thanks. -- Henry Throop THROOP@GRIN1.BITNET throoph@jacobs.cs.orst.edu hilbert!throop@atanasoff.iastate.edu
toddpw@nntp-server.caltech.edu (Todd P. Whitesel) (12/09/90)
throop@hilbert.UUCP (Henry Throop) writes: >Maybe this has been discussed before, but I don't remember seeing it. Does >anyone know what the format of a 1.44 MB floppy is based on? Is it the same >as a 720K (IBM) 3.5, but just with twice the number of tracks, and thus >a constant angular velocity? Or is is some variant on the 800K formatting? >Are Mac and IBM 1.44 disks readable (sector-wise) by the same drives? What I do know: IBM drives are CAV, and the Apple drives aren't. For the actual bit encoding on the disk, IBM drives use MFM as opposed to the GCR used by Apple drives before the FDHD. These encodings are how the bit stream actually appears as pulses on the disk, and are generally implemented in hardware. MFM is a simple technique, but GCR stores about 20% more data on the same disk. The difference between the two is basically a change in the digital state machine that sits between the disk interface and the actual drive head. Apple's push towards IBM formats is because of their business thrust. I gotta admit it would be nice to read IBM formats, but to do it AE would have to make what would amount to a beefed up Unidisk. AE is opting for performance and storage rather than IBM compatibility. Todd Whitesel toddpw @ tybalt.caltech.edu
kpopple@imp.sim.es.com (Ken Poppleton) (12/11/90)
In article <1990Dec9.130157.10685@nntp-server.caltech.edu>, toddpw@nntp-server.caltech.edu (Todd P. Whitesel) writes: > > Apple's push towards IBM formats is because of their business thrust. I > gotta admit it would be nice to read IBM formats, but to do it AE would > have to make what would amount to a beefed up Unidisk. AE is opting > for performance and storage rather than IBM compatibility. If you want an IBM PC Compatable disk drive for your apple, contact Patrick McLaughlin of Convergent Technology (CTI). (801) 364-4171, mail 516 12th Ave Salt Lake City Utah 84103. He is marketing a disk controller card for the Apple II line which allows the reading and writing of IBM PC Compatable disks. It will support 360k 5.25 or 800k 3.5" drives. It could also be made to read other disk formats. Cost for the card is only $70, and drives near $100 is low for Apples! They work well, at least in the small use I have given them. Prodos and Apex only on my Apple IIe and Apple II+ ---------------------------------------------------------------------------- Ken Poppleton kpopple@esunix@orca.es.com
AABENSON@MTUS5.BITNET (12/12/90)
Ken Poppelton was talking about a 3rd part IBM disk drive for Apple II's.
Just wondering, do they come with GS/OS device drivers?
- Andrew.
Internet: aabenson@balance.cs.mtu.edu Bitnet: AABENSON@MTUS5.BITNETjgieske@polyslo.CalPoly.EDU (John Erik Gieske) (12/15/90)
Seeing all of the debate/interest created by AE's FDHD, I thought this may be
of some interest to you GS users:
Quoted without permission from MicroTimes December 10, 1990 page 218
The Insite I325VM (variable mode) Floptical disk drive is the first 20Mb
3.5" floppy disk drive also able to read and write standard Double
Density and High Density diskettes. This is achieved by merging optical
and magnetic recording technologies with the use of low cost components
developed for compact disk recording as well as traditional magnetic
floppy diskette drive assemblies. The Floptical is designed to plug
and play with existing SCSI host adapters for IBM PC, XT, AT, PS/2, Mac,
and other SCSI-compatible computers. Insite Peripherals, Inc., 4433
Fortran Dr., San Jose, CA 95134. (408) 946-8080
Note: I am not employed by MicroTimes, nor by Insite Peripherals.
I just wanted to share some information.
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