You should probably define "Presentation Manager".
Didn't OS/2 1.2 have Presentation Manager?
My OS/2 2.11 has a couple of floppy disks labeled "Multimedia Presentation Manager".
Was Presentation Manager in OS/2 Warp Version 3 the same thing?
Dave
Presentation Manager (PM) is the window management component of OS/2 - mainly window handling and related.
MMOS/2 (or MMPM/2, Multimedia Presentation Manager/2) was/is the multimedia component - video and audio. Currently OS/2 and eCS work on the Warp 4.52 version of Presentation Manager to show the desktop and all its windows.
IIRC, OS/2 had a Presentation Manager also in its 1.2 release, much different from the 2.0+ releases in code, features and appearance (OS/2 1.2 shares much code with the older versions of Windows NT/2000, to the extent that many character mode OS/2 applications run flawlessly under NT/2000).