All versions can now be downloaded from Tvdog’s archive and also from WinWorld. At the time Tandy also released generic PC-compatible versions of DeskMate which contain all features except the music composer (MUSIC.PDM) and sound editor (SOUND.PDM). From this, the version installed on my computer at the time is most likely DeskMate 3.04.04 shipped in 1991, specifically designed for Tandy machines. After a quick search I found a detailed history of DeskMate on toastytech that lists all versions of DeskMate known to have existed.
Time passes by and recently I found myself playing with DeskMate again, not on the original Tandy machine which has long been thrown away, but on DOSBox. Yet I spent hours daily playing with the Tandy and even wrote my first lines of codes using Turbo Pascal 5.5 on it.
With the small hard disk drive, not many software could be installed, only Tandy Deskmate, Windows 3.1, Microsoft Office 4.3 and some DOS games. It has a 25MHz 80386SX processor, 4MB of RAM and 100MB hard disk drive.