File Manager and Shell Report Total Size of CD-ROMs as 128 MB (120898)



The information in this article applies to:
    Microsoft MS-DOS operating system 3.1
    Microsoft MS-DOS operating system 3.2
    Microsoft MS-DOS operating system 3.21
    Microsoft MS-DOS operating system 3.3
    Microsoft MS-DOS operating system 3.3a
    Microsoft MS-DOS operating system 4.0
    Microsoft MS-DOS operating system 4.01
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 5.0a
    Microsoft MS-DOS operating system 6.0
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q120898

SUMMARY

File Manager and the MS-DOS Shell may report 128 megabytes (MB) as the total size of a CD-ROM and zero (0) MB as the amount of free space. This occurs because the Microsoft CD-ROM Extensions (MSCDEX) reports 128 MB as the capacity of a CD regardless of the real capacity or true remaining free space on the CD.

MORE INFORMATION

MSCDEX reports 128 MB for the MS-DOS DISK INFO function call. This MS-DOS API is used by File Manager and Shell. Although it is not difficult to find the capacity of a CD-ROM, MSCDEX does not use this information. MSCDEX reports a total of 65,535 clusters of 2 kilobytes each and 0 free clusters.

Modification Type: Major Last Reviewed: 5/6/2003
Keywords: KB120898