Here is the whole disk that came with the 56K MiniTower. It only seems to install a help file, which is really no help at all. Try the INF file first. If that doesn't do it, unzip this and run SETUP.
The following files are found inside the driver download file.
|SETUP.INS||35.5 KB||25 Oct 1994|
|SETUP.EXE||291.3 KB||8 Apr 1994|
|Pm56kmt4.inf||37.3 KB||19 Aug 1997|
|INS0762.LIB||72.7 KB||17 Jun 1997|
|DATA.1||179.4 KB||17 Jun 1997|
|SETUP.PKG||140 bytes||17 Jun 1997|