2 prototype hard drive controllers, not Enterprise or Intelligent Software based - the boards are dated 1992! It's basically an extra board that's connected to the usual EXDOS board to allow access to an extra ROM and a standard 8-bit PC ISA disk controller, in this case a Seagate R11 from an IBM PC - thereby giving you instant access to IBM-compatible RLL/MFM type hard drives as used in said IBM PC. One of these days I hope to have enough knowledge to be able to rebuild these!

If you've heard of these things please let me know!