These are 360k disk images.  You need Teledisk to recreate the disks.
Teledisk can be found at:

    ftp://tvdog.shacknet.nu/tandy1000/system/teled212.zip

The disks should be labelled:

Startup.td0       MS-DOS - Startup
Operting.td0      MS-DOS - Operating

This is a generic DOS 3.3 version for the Tandy 3000- and 4000-series.
