CDC Hawk Drive

The Control Data Corporation Model 9427H Hawk drive is an 14-inch disk drive that features one 5MB fixed platter and one 5MB removable platter. The Hawk drive is an absolute beast, weighing in at a very heavy 135 lbs., or 61 kg. However, when released, it featured some of the most massive data storage and fastest read and write times around. The Hawk Drive command cable can be daisy chained with other Hawk drives or Falcon drives and the DSK1/DSK2 Controller Boards can support up to four drives.

Here is a photo of the Hawk drive with most of the covers removed:

When installed in the machine, it is very nice looking.

Connection Interface

The Hawk uses a 50-pin command and control cable that can daisy chain with up to four different drives. Here is the interface diagram from a brochure:

However, the input output lines are a bit more in-depth than what is shown in the brochure diagram above. This spreadsheet shows the input and output lines in more detail and was taken directly from the CDC maintenance manual.

Data Arrangement

The Centurion organizes the data in a very specific way on the platter. Below is a diagram drawn from the memory of the amazing Ken Romaine that shows how exactly the magnetic flux of each sector is laid out.

The Control Boards

The Hawk Drive features a separate, dedicated card cage for the majority of the control circuitry on the machine. Not pictured below is the voice coil control board that sits atop the voice coil itself as well as the power supply control boards (I will get pictures of those and post them up one of these days). The five main control boards inside the card cage that plug into the passive backplane are the Read/Write, Servo, Control, Sector and Data boards. These are perspective distorted photographs and as such are not the highest quality. In the future I will take scans of each board for a more detailed and easier to see photo.

Read/Write Board:

Servo Board:

Control Board:

Sector Board:

Data Board:

Interface Board: