ee5391aa@triton.unm.edu (Duke McMullan n5gax) (05/17/91)
Just that...how? For background, I have a 12MHz `286 box, which runs messdos 3.3 with 4dos. Drive A: is a high-density 5.25" floppy; drive B: is a high- density 3.5" microfloppy. Can this be done? Am I staring right through the answer, which is sitting right there in the doc.s for all to see? Thanks, d
pmwenzel@ziggurat.gg.caltech.edu (Pete Wenzel) (05/17/91)
In <1991May16.220514.23423@ariel.unm.edu> ee5391aa@triton.unm.edu (Duke McMullan n5gax) writes: >Just that...how? For background, I have a 12MHz `286 box, which runs messdos >3.3 with 4dos. Drive A: is a high-density 5.25" floppy; drive B: is a high- >density 3.5" microfloppy. Can this be done? Am I staring right through the >answer, which is sitting right there in the doc.s for all to see? Actually, the answer is in 4dos' help screen. Hitting F1 and looking up FORMAT, I find that FORMAT B: /T:80 /N:9 does the trick. --Pete ____ ____ _/ \ Pete Wenzel - Caltech Computer Graphics Group / \_ / _ `--_ __ pmwenzel@smoggy.gg.caltech.edu _____--' _ \ | | \ ---\_/---\ home (818) 577-9005 ,_/------- / | | | |_/ ----------`-^-^\ lab (818) 397-2820 /^-^-^-'---------- \_| | \_ ___=============/ FAX (818) 793-9544 \===============___ _/ \____/ Mail Code 256-80, Pasadena, CA 91125 \____/
c164-al@katerina.uucp (Joon Song) (05/17/91)
In article <1991May16.220514.23423@ariel.unm.edu> ee5391aa@triton.unm.edu (Duke McMullan n5gax) writes: >Just that...how? For background, I have a 12MHz `286 box, which runs messdos >3.3 with 4dos. Drive A: is a high-density 5.25" floppy; drive B: is a high- >density 3.5" microfloppy. Can this be done? Am I staring right through the >answer, which is sitting right there in the doc.s for all to see? > > Thanks, > d It seems that most 3.5" drives look for a hole in the disk casing to determine the density of the media. So if you want to format a high-density 3.5" disk to 720K, just cover the high density hole with some scotch tape. Now you have a high density disk which looks like a double density disk to the disk drive. However, if you take scotch tape off and uncover the high density hole, the disk will probably be unreadable on most machines. Now some people out there are probably going to say something like: "all you need to do is type 'format b: /t:80 /n:9' from the command line". Well, that may work on some machines (most notably IBM PS/2s), but on most machines, a high density 3.5" disk drive will refuse to format a HD disk to DD for the same reason that it will refuse to format a DD disk to HD. (I know that doesn't make any sense, but it's true.) Joon Song
mdvries@cwi.nl (Michiel de Vries) (05/17/91)
pmwenzel@ziggurat.gg.caltech.edu (Pete Wenzel) writes: >>Just that...how? >> drive B: is a high-density 3.5" microfloppy. Can this be done? [Formatting a 1.44 MB disk to 720 kB] >I find that FORMAT B: /T:80 /N:9 does the trick. This didn't work for me; disk are "original" 720k disk, so no HD hole. I added a "DEVICE=DRIVER.SYS ...." (don't have the parameters here) line to my config.sys. I do now "FORMAT E:" for 720 k flop's (still no HD holes!). Both 720k & 1.44M disks can be read in drive B: & E: P.S. I am surprised this issue isn't in the FAQ's. -- Michiel *** mdvries@cwi.nl Michiel de Vries, CWI, Amsterdam, The Netherlands. Room: M133, Tel: (+31)020-592.4114
curlandm@prism.cs.orst.edu (Matt Curland) (05/17/91)
Since I don't have to do this very often (format a 720k disc), What I do is run the BIOS setup and change the drive type to 720k, then change it back afterwards. Matt Curland.. . . . . . . curlandm@prism.cs.orst.edu _____________________________________________________________________________
jupakkanen@cc.helsinki.fi (05/17/91)
In article <1991May16.220514.23423@ariel.unm.edu>, ee5391aa@triton.unm.edu (Duke McMullan n5gax) writes: > Just that...how? For background, I have a 12MHz `286 box, which runs messdos > 3.3 with 4dos. Drive A: is a high-density 5.25" floppy; drive B: is a high- > density 3.5" microfloppy. Can this be done? Am I staring right through the > answer, which is sitting right there in the doc.s for all to see? > > Thanks, > d I don't know about the 4DOS, but with PC/MS-DOS the command is: FORMAT b: /n:9/t:80 Also, with some verions of DOS you can try format b: /7, but the above should work with all versions. Jukka
tanida@forseti.css.gov (Tom Tanida) (05/18/91)
In article <1991May17.081931.7014@agate.berkeley.edu>, c164-al@katerina (Joon Song) writes: >It seems that most 3.5" drives look for a hole in the disk casing to >determine the density of the media. So if you want to format a high-density >3.5" disk to 720K, just cover the high density hole with some scotch tape. >Now you have a high density disk which looks like a double density disk to >the disk drive. However, if you take scotch tape off and uncover the high >density hole, the disk will probably be unreadable on most machines. > >Now some people out there are probably going to say something like: > "all you need to do is type 'format b: /t:80 /n:9' from the command line". > >Well, that may work on some machines (most notably IBM PS/2s), but on >most machines, a high density 3.5" disk drive will refuse to format a HD >disk to DD for the same reason that it will refuse to format a DD disk to >HD. (I know that doesn't make any sense, but it's true.) A lot of drives don't look for the extra hole that is characteristic of the HD media, but, because of all the types of disk drives out there, you never know (and hence I agree with this). There is another issue: You will get some kind of weird failure error if you take a previously formatted, HD disk and try to low-density format it. This comes from the 'media descriptor' byte, located on the very first absolute sector on the disk. For some lame reason, some format programs look at this and balk if you attempt to switch densities on them (including the Norton format program, at least in version 4.5). If you 1) use a magnet to wipe the disk out, or 2) use some sector editor to change the media descriptor byte, you can switch formats. I don't know off hand what the values are or what the exact location of this byte is on the disk (other than that it's in the first absolute sector- sector 1, not 0, don't ask me why that is either :-) ). This puzzled me for the longest time until I stumbled across it in Hayden Books' "Advanced MS-DOS Programming", which covers both absolute and MSDOS logical disk layouts. -Tom tanida@esosun.css.gov
phil@brahms.amd.com (Phil Ngai) (05/18/91)
I use Microsoft Windows 3.0 file manager. -- "1935 will go down in history! For the first time, a civilized nation has full gun registration! Our streets will be safer, our police more efficient and the world will follow our lead into the future!" - Adolf Hitler