berger@clio.las.uiuc.edu (09/07/88)
That's a tough one. Most of the 3.5" drives I've seen ignore the extra
hole entirely. In most cases, formatting is strictly a software option.
But some drives do read that hole, so there's no guarantee for any
particular system.
Mike Berger
Department of Statistics
Science, Technology, and Society
University of Illinois
berger@clio.las.uiuc.edu
{ihnp4 | convex | pur-ee}!uiucuxc!clio!bergercoulter@hpclisp.HP.COM (Michael Coulter) (09/07/88)
On my system, to format a 720Kb 3.5" floppy on a 1.44Mb drive: format b: /N:9 /T:80 -- Michael Coulter ...ucbvax!hpda!coulter
bill@hpcvlx.HP.COM (Bill Frolik) (09/07/88)
Depends on the hardware. If you're using an IBM PS/2 machine, the hardware doesn't let software find out whether the hole is there or not, so the format program just always assumes it's a 1.44M disk unless you specify otherwise. To format a 720K disk in the PS/2 1.44M drive, you have to say FORMAT A: /N:9 (9 sectors per track instead of 18). They even put a warning in the User's Guide telling you not to format a 720K disk in a 1.44M drive using FORMAT defaults, and not to format a 1.44M disk as 720K using the /N:9 switch. What this gets you is flexibility; you can use high density disks that don't have the extra hole. It can also make things confusing. In HP's Vectra CS (and probably machines from other manufacturers, too) the hardware senses the extra hole and the BIOS recognizes what type of media is in the drive. In that case, you just say FORMAT A:, and if you have a 720K disk in the drive, you get 720K; a 1.44M disk gets you 1.44M. ----------------------------------------- Bill Frolik Hewlett-Packard hplabs!hp-pcd!bill Corvallis, Oregon
thaler@speedy.cs.wisc.edu (Maurice Thaler) (09/08/88)
I just did the old solder iron trick last night. First I tried to format the floppy w/ no arguments. It came back w/ BAD TRACK 0. After the "operation", it formatted to 1.44M w/ no problems. I am filling it w/ ARC files. To check if the floppy is degrading, all I have to do is PKXARC /T * it will check the contents of each file inside the ARC to a crc on each file. If there is any damage to the floppy, it will show up immediately. I will do this on a few more floppies and report back if errors start creeping in. So far, so good though. This reminds me of the old single sided floppy days. I very rarely found a SS/DD that did not format perfectly to DS/DD.
burleigh@silver.bacs.indiana.edu (frank burleigh) (09/08/88)
In article <101000002@hpcvlx.HP.COM> bill@hpcvlx.HP.COM (Bill Frolik) writes: > >otherwise. To format a 720K disk in the PS/2 1.44M drive, you have to >say FORMAT A: /N:9 (9 sectors per track instead of 18). They even put >a warning in the User's Guide telling you not to format a 720K disk in >a 1.44M drive using FORMAT defaults, and not to format a 1.44M disk as >720K using the /N:9 switch. What this gets you is flexibility; you can In PC/MS-DOS 3.3 the format command for a 720KB disk in a PS/2 or other machine with a 1.44MB drive is FORMAT A: /N:9 /T:80 unless the hardware knows what sort of disk is in the drive, as Mr Frolik says. In DOS 4.0 they say you may use 720 on the format line to get the correct formatting. -- Frank Burleigh/ Dept. of Sociology/Indiana University, Bloomington, IN 47405 USENET: ...rutger4!iuvax!silver!burleigh 812/333-7082, 335-4127