This was
Advanced Digital Corp's one and only board to interface with a hard disk.
It represented state of the art at the time.
The HDC-1001 was an S-100 bus Winchester hard disk controller board with
error correction (ECC) capabilities. It was designed to interface up to four
Winchester disk drives. There were two versions of the board, the
HDC-1001-5/8. The HDC-1001-8 operated on 8" drives. The HDC-1001-5 was used
with most 5-1/4" drives. The drive signals were based upon the floppy
look-alike interface available on the Shugart Associates SA1000, the Seagate
Technology ST506, and other compatible hard drives. All necessary buffers
and receivers/drivers were included on the board to allow direct connection
to the drive. Four 20 pin radial connectors were provided for data. Either a
34 pin (5" drive) or a 50 pin (8" drive) connector was provided for drive
control. All data to be written to or read from the disk, status
information, and macro commands were transferred via the S-100 bus. An on
board sector buffer allows data transfers to the host computer independent
of the actual data transfer rate of the drive.
The board utilized the Signetics 8X305 bipolor microcontroller to talk to
the hard disk. .
This board was IEEE-696 compatible and really well laid out.
The excellently written manual for this great looking board can be obtained
here.
