Blame Peter
It's the old parallel adapter for the HP ScanJet Plus GS-scanner. You could use the card as additional parallel port - for a ZIP drive or external PP CD-ROM probably ... just in case you don't have the appropriate scanner.

AdapterId 0601Fh "Hewlett-Packard Scanner Interface Adapter"

I/O Port Location
 This adapter requires eight I/O ports.  There are four choices for the location of these ports
    <278-27F (PARALLEL_3)>, 268-26F, 258-25F, 248-24FH

Memory Location
   This adapter requires 16 Kbytes of memory space from the adapter ROM area.  There are eight memory locations that can be selected.
   <Segment C400>, CC00,  DC00,  D800,  D400, D000, C000, C800

HP ScanJet IIp Scanner (PC / MCA)
http://www.hp.com/cposupport/prodhome/sjiippm.html

SOLUTION: The file is on the installation disk #1 of the HP DeskScan II or HP PictureScan software. The file name for the HP ScanJet Plus is @601f.adf. For the HP ScanJet IIc and
HP ScanJet IIp scanners the file is @621f.adf for the ROM addressing card (C1753). The file name for the HP ScanJet IIcx, HP ScanJet 3p, HP ScanJet 3c, HP ScanJet 4c, and HP
ScanJet 4p Input/Output (I/O) addressing card (C2503) is @631f.adf.

 SUMMARY: The ADF file is an Adapter Description File for the Micro Channel Configuration program. It is used as a reference for setting the ROM address for the HP ScanJet Plus, IIc and IIp card, and the I/O address for the HP ScanJet IIcx, 3c, 3p, 4c and 4p card.