Why is the DOS path character ''?

Many, many months ago, Declan Eardly asked why the \ character was chosen as the path separator. The answer's from before my time, but I do remember the original reasons. It all stems from Microsoft's relationship with IBM. For DOS 1.0, DOS only supported floppy disks. Many of the DOS utilities (except for command.com) were written by IBM, and they used the "/" character as the "switch" character

[rin51]

パス区切りが\になった理由。/は使えない(IBMが作ったDOS1.0が/をスイッチとして使ってたから)、\は/と見た目が似てるから採用した。らしい