[Supplement]
If after booting into DOS, you then load disk drives (such as USB devices), the drive letter of TODISK will be incorrect. (Driving the CD-ROM is fine because the CD-ROM is not a disk.)
Therefore, it is recommended not to use drive letters to represent partitions. (However, when used with files, of course, drive letters must be used, and only drive letters can be used, not numbers.)
If after booting into DOS, you then load disk drives (such as USB devices), the drive letter of TODISK will be incorrect. (Driving the CD-ROM is fine because the CD-ROM is not a disk.)
Therefore, it is recommended not to use drive letters to represent partitions. (However, when used with files, of course, drive letters must be used, and only drive letters can be used, not numbers.)

