What is the Myarc HFDC card?
The Myarc HFDC is a Hard Disk and Floppy Disk Contoller card. While it does support floppy disks the main feature is that it support MFM based hard disks. Getting a HD on your TI is one of the more difficult tasks; this is not for technical reasons but more of availability. The Myarc HFDC, SCSI cards like the SNUG ASCSI and the IDE project card are the three main options. The Myarc HFDC and SCSI cards seem to be the better of the three.