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Aptiva - Can a 1.0MB (720K) diskette be formatted and used as a 2.0MB (1.44MB) diskette?

Applicable to: World-Wide

When you look at diskettes, you may notice that some diskettes have a hole on the right side as well as the left side (the hole is the write protect hole). The diskettes with a hole on the right and left are 2.0MB diskettes. This is the only apparent physical difference in 2.0MB diskettes compared to 1.0MB diskettes.

Users have found that they can purchase a 1.0MB diskette and format it as a 2.0MB diskette. Many have found that when they do this, then take the diskette to another computer, the other computer will not read the diskette. This happens because different drives work different ways. Many diskette drives use a device that checks for a hole on the right side of the diskette. If the diskette drive finds a hole on the right side, the drive knows the diskette is 2.0MB. If the hole is not found, the drive thinks that the diskette is a 1.0MB diskette.

Some drives used by IBM do not have such a device. Because of this, the IBM drive will format the diskette based on the specifications given by the user. So, if someone wants to (or inadvertently does) format a 1.0MB diskette as a 2.0MB diskette, the drive may allow this. The drive does not check the diskette to see what the capacity of the diskette is supposed to be. If the diskette is then taken to a computer that does check for the hole, problems occur. The other computer's drive does not find the hole in the right side and thinks the diskette should have a 1.0MB format. When the computer encounters the 2.0MB format, it doesn't understand why a 1.0MB diskette has a 2.0MB format. Therefore, the computer generates errors.

Since some diskette drives do not check for the hole indicating whether the diskette is 1.0MB or 2.0MB, if you specify a 1.0MB diskette to be formatted as a 2.0MB diskette, the diskette will be formatted as such. In most cases, this is fine. By doing this, a user can get double the storage capacity. But, there is always a chance that some part of a file will be written on a very small defect on the diskette. This can cause file corruption, if the file is saved on that portion. There is no way to give a reliability or safety factor for a 1.0MB diskette formatted as a 2.0MB diskette. Diskettes go through a certification process in which they are classified as 1.0MB or 2.0MB diskettes. Whether or not one wants to take this chance is up to the user. If you do customarily format 1.0MB diskettes as 2.0MB diskettes, it is a good idea to frequently backup your work.

	Search Keywords
	Hint Category	Diskette Drives
	Date Created	19-03-97
	Last Updated	18-02-99
	Revision Date	18-02-2000
	Brand	IBM Aptiva
	Product Family	Aptiva, PS/1
	Machine Type	2134, 2136, 2137, 2138, 2140, 2142, 2144, 2159, 2161, 2162, 2168, 2176, 2011, 2121, 2123, 2133, 2155
	Model	all
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