There are two sides to getting this sorted: the drivers for the device, and then the networking protocol you're going to use. But the archive PCMPC100.EXE seems to have most of what you'll require.
MS-DOS doesn't have any native support for PCMCIA cards, so you'll want to load a card enabler for your Etherfast. You'll find a copy of it in the ENABLER folder of the archive you downloaded. There's some guidance in an online copy of the Etherfast's manual here, but it largely boils down to:
- Telling EMM386 to reserve some memory space for the enabler, with a line in your CONFIG.SYS like:
DEVICE=C:\EMM386.EXE NOEMS X=D000-D3FF
- Running the enabler when you boot the computer by adding a line to your AUTOEXEC.BAT
If you intend to use different PCMCIA cards, and hot-swap between them, you may want to look at the contents of the PCMCIA folder. These are configuration files for three different card management services that were available in the DOS era: PCM+, SystemSoft and Cardware. If you're just going to use the Etherfast (or restart the machine to swap cards) then you don't have to use them.
You will also have to load a driver for your card. There are multiple drivers provided, for the different networking systems that were available at the time. So first you'll have to decide on a networking protocol.
Your three main options are:
- Novell Netware (with drivers in the NETWARE folder)
- Microsoft LAN Manager (drivers in MSLANMAN.DOS)
- A Packet Driver for general TCP/IP networking (drivers in PKTDRV)
As you are looking to share files over a local area network, I'd suggest Netware or LAN Manager (LANMAN) instead of a packet driver, as they were specifically designed for this task. If you choose to go for a packet driver, you'd then need to find DOS software to communicate over the network (such as FTP clients or similar). And as you're going to be sharing files with a Linux machine, my suggestion would be to opt for LANMAN. Why? Because it is the protocol that developed into Windows' SMB file sharing system. And the Linux equivalent, Samba, specifically supports networking with DOS machines.
Assuming you select LAN Manager and Samba as your solution, you will need to install a copy of MS LAN Manager Client (Version 2.x would be my suggestion) on your machine, and load the drivers from the MSLANMAN.DOS folder in your archive.
When configuring Samba, you will have to tell it to use the older, insecure version of the LAN Manager hash for storing passwords. To compensate for this, you may wish to configure Samba to ignore any requests except from your machine (i.e. on a per-IP or subnet basis) or set up a separate network for this purpose.