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:

Disk1.td0      MS-DOS/GW-Basic 3.2.0
Disk2.td0      MS-DOS - Supplemental Programs
Disk3.td0      DeskMate II 1.0.0
Disk4.td0      DeskMate II Sample Files

The DOS disk contains Tandy DOS 3.2, which is usable on other 1000-
series models (it will not run on a non-Tandy machine).
