The HD disks have a higher coercivety oxide than the non-HD versions. Or if it's the HP 86 drive, make sure your disk is *not* HD but a true 720K disk. Message #4 Posted by sbirdasn on 9 June 2005, 9:55 p.m., I know I used this trick a long time ago to allow me to copy some 720Kb disks to 'new' media a long time ago - but I can't remember what type of machine it was on.

On some drives is isn't possible to use format a 'new' 1.44 Mb blank disk as 720Kb as they have a sense switch, this can be defeated by covering the hole opposite the write protect tab with insulating tape (no selotape as this passes light). I don't remember the link.Ī 720KB drive is better than a 1.44MB one. You need to use LIFUTILS to be able to read/write an HP-86 floppy on a PC. In response to message #1 by Tyson Wenger Message #2 Posted by Patrice on 9 June 2005, 3:05 p.m.,

Does anybody have any idea what I can do to fix this? I obviously can't make a copy on newer pc's because the file format isn't supported. It either just sits for a long time and doesn't complete or it spits out this 'error 129: medium'.

Whenever I execute the command: INITIALIZE 'TEST', ':D700', 13, 7 the red light goes on but the disk never gets finished. I can't seem to initialize a new dd disk on the system though. I'm trying to get a backup of a 3.5 floppy disk, 720K DD that has a program for the hp-86 on it. Message #1 Posted by Tyson Wenger on 9 June 2005, 11:44 a.m. HP-86 disk backup The Museum of HP Calculators

How to format 3.5 floppy disk as 720 kb