File C905CTXB.EXE is Diskette #2 of 3 for 3Com's 3C905C-TX and 3C905-TX-M EtherLink Family, 10 Mbps Ethernet PCI Network Interface Card. This diskette, version 5.01, supports 3Com's 3C905C family of PCI network NICs with a common driver set. Drivers on this diskette support: 
Windows for Workgroups 3.11
Clarkson Packet Driver
NetWare Client 32
Also includes DynamicAccess Technology

These adapters are in the IBM OBI CTO Portfolio and are assigned IBM P/N's. 
3C905C-TX  =  IBM P/N 01N0533 with an IBM FRU number of 01N0535.   
3C905C-TX-M  =  IBM P/N 01N3699 with an IBM FRU number of 01N3609.