On top of the issues that caused with transferring files to 'normal' machines they regularly ended up with damaged files even on the PS/2s. Way back in my youth I worked at an office that used those early PS/2 machines (55sx-s, mostly) that lacked the density detection sensor on their 3 1/2 inch drives, and people there were constantly formatting 720k disks as 1.44MB. You might pull off doing a quicky disk-image transfer to get a target machine going but if intend to keep your unfinished Great American Novel on floppies I'd highly recommend using the correct media. But there is no magic that will let you use the wrong media at the wrong data rate/capacity.Įven if you do manage to format the high-density disk at the lower write current I'd certainly be hesitant to trust anything of value to it. Here is a human readable description of what is going on:Ī 'bulk eraser' does magic in cases like this to make the diskette usable for its intended purpose. It still uses the correct write current, but it takes advantage of the tighter track pitch on the 1.2MB drives.) Here is an example of bending the rules and using a format that is not intended for the media type: FdFormat has a neat trick where it can put 80 tracks on a double density disk. You can do it with an advanced formatting program and make it work on a high density diskette, but that diskette won't be readable in a standard 360K drive - the media is the wrong type and the tracks are too close together. But most floppy diskette formatting programs also force the double density data rate when you specify that format, which is a no-no for high density media. You can put a 360K filesystem format on a high density disk - that just means you are using 2 sides, 40 tracks and 9 sectors per track out of the 2 sides, 80 tracks, and 15 sectors per track that are available. You get into trouble when you try to force it one way or the other with the wrong media type. They adjust the write current to suit the media.

High density drives can work with both types of media. (Contrast this with an old hard drive, where low level formatting is done as a separate step.)ĭouble density media is different than high density media. When formatting a floppy drive both are done in the same pass. Keep in mind that there are two levels of formatting going on - low level and filesystem level.

How to format a floppy disk in dos