broman@cod.UUCP (Vincent P. Broman) (10/13/87)
Does anyone know how to format floppies to a size of 400K? I know it was done under some P-system (not Pecan) which did not depend on MS-DOS. I suppose that one formats 10 sectors on a track instead of the standard 8 or 9, (though I wonder whether 5 doubly long sectors could have been used instead). The ROM BIOS supplies an interrupt service for formatting various sector sizes and numbers, but it seems to depend on a mysterious disk parameter table with abstruse entries for intersector gaps and other arcana not documented. Supporting "bigger" floppies with standard hardware would be very natural for Minix to attempt. Once you are able to format the disks, it should be straightforward to alter the floppy driver to read and write it. The main difficulty I see is in simultaneously supporting 360K and 400K floppies with the same driver. Perhaps the file system's size field is just the thing to differentiate between the two varieties at runtime. Vincent Broman, code 632, Naval Ocean Systems Center, San Diego, CA 92152, USA Phone: +1 619 225 2365 Internet: broman@nosc.mil Uucp: sdcsvax!nosc!broman
hollen@mana.megatek.uucp (Dion Hollenbeck) (10/15/87)
In article <860@cod.UUCP> broman@cod.UUCP (Vincent P. Broman) writes: >Does anyone know how to format floppies to a size of 400K? > I don't know exactly how the DPB is used for gaps and such, but I have what I believe to be a public domain package called JFORMAT which uses among many other formats, a 400k format. It provides not only a formatter, but a device driver as well. I am sure that by debugging how it works on DOS, you could develop a model for your MINIX implementation. The only problem is that the documentation does not say for sure that this is public domain or not. There is no copyright notice. Does anyone out there know for sure? If it is determined to be public domain, I would be happy to E-mail and if enough interest, post to the net. Dion Hollenbeck (619) 455-5590 x2814 Megatek Corporation, 9645 Scranton Road, San Diego, CA 92121 ames!scubed! {sdcsvax,hplabs}!hp-sdd!megatek!hollen sdcsvax!esosun!
nather@ut-sally.UUCP (Ed Nather) (10/17/87)
In article <198@megatek.UUCP>, hollen@mana.megatek.uucp (Dion Hollenbeck) writes: > In article <860@cod.UUCP> broman@cod.UUCP (Vincent P. Broman) writes: > >Does anyone know how to format floppies to a size of 400K? > > > > I don't know exactly how the DPB is used for gaps and such, but I have > what I believe to be a public domain package called JFORMAT which uses > among many other formats, a 400k format. It provides not only a formatter, > but a device driver as well. > There is no copyright notice. Does anyone out there > know for sure? If it is determined to be public domain, I would be happy > to E-mail and if enough interest, post to the net. The copy you *did* post to the net has, in ASCII in jformat.com, the notice Copyright (c) 1983, 1984 Tall Tree Systems so it doesn't look like public domain software to me. In the file qdrive.bin there is the copyright notice and a version number v2.30. The .doc file caused both arc and pkarc to throw up their hands in horror, so I don't know what it contained. Given the command you recommended in "readme.1st" the unpacked jformat.com formatted a floppy disk at 322K, not the 401K requested. I suggest anyone in receipt of the referenced posting erase it. -- Ed Nather Astronomy Dept, U of Texas @ Austin {allegra,ihnp4}!{noao,ut-sally}!utastro!nather nather@astro.AS.UTEXAS.EDU
ugfailau@sunybcs.uucp (Fai Lau) (10/18/87)
In article <860@cod.UUCP> broman@cod.UUCP (Vincent P. Broman) writes: >Does anyone know how to format floppies to a size of 400K? > Why go through the trouble when you can get a 1 Meg disk drive? My sister has one and it seems to be pretty reliable. Fai Lau SUNY at Buffalo (The Arctic Wonderland) UUCP: ..{mit-ems|watmath|rocksanne}!sunybcs!ugfailau BI: ugfailau@sunybcs