CompuPro - Disk 1
The Disk 1A was as CompuPro's first floppy disk controller. It still used an Intel  8272 or NEC 765A floppy disk controller instead of a at the time, then more common Western Digital 1791-7 chips. The board had a basic serial I/O port to boot the system for the first time. with CompuPro's disk software.

What was interesting about both the Disk1 (and Disk 1A) was that the boot ROM had code which via a switch selection could be used to work with either a 8085/Z80, a 8088/8086/80286, a 68000 or a 32016 CPU based system. The board handled data transfers via 24 bit DMA with the ability to cross 64K boundaries.  There was a priority arbitration scheme for the on-board DMA circuitry that will allow up to 16 temporary bus masters to operate without conflict.  There was an advanced digital data separator for reliable data transfers. No cap or resistor adjustments were required. The board had provisions for running both 5.25" and 8" floppy drives though not at the same time. %' drives required a slight board modification and careful cable connector seating.
 
Every effort was taken to make it easy for the first time user to get a floppy disk system going in their system.  The manual gave detail descriptions of hardware and software combinations needed. The default board port addresses were C0H - C4H. Apparently 5" drives are different (CCH to CFH).
 
The serial port on the DISK 1 was designed for initial system startup only and should not be used as the console device for longer than required to patch the BIOS. Since this port is controlled entirely by software, its baud rate was dependent on the host processor's clock rate. See the manual for details.
 
The manual can be obtained here.