CDC 854
            disk driveDate of introduction: 1968-69?

Type: Disk Drives using removable disk packs

Capacity per drive:

    256 six-bit characters per sector

    16 sectors per track

    200 (plus 3 spare) tracks per disk surface

    6 disks with 10 usable disk surfaces

    This results in 8.192.000 characters (corresponds to 6.1MBytes)

Disk pack: CDC 851 or equivalent

Rotational speed: 2400RPM

Positioning technique: Photo-electric track sensing and mechanical (detentl gear) positioner

Positioning time track-to-track (average): 30ms

Power requirements: 208V, three-phase, 3A per phase

Dimensions: Height: 103.5cm (40.75"), Width: 61cm (24"), Depth: 91,4cm (36")

Weight: 217.6kg (480pounds)

S/N: 5306


This Control Data disk drive designated as the "854 Disk Storage Drive" was part of the large haul of computer artefacts discovered in Dortmund in spring 2012 that were the remainings of the Computer Museum Aachen (Germany). When I saw this drive for the first time, it still had a disk pack in it. When I came back later to pick it up together with other peripherals and systems, the disk pack was missing. Another collector probably took it. I wonder if he or she als has such a drive or took it to serve as an exhibition piece.

The first set of pictures shown in the "pictures" section were taken in the old hangar where that disk drive was exposed to climate changes, dust and humidity over several years. The front cover hiding the disk logic boards was missing, but I found a replacement one in a different corner of the hangar.

This disk drive still needs to undergo restoration. I will add new and better pictures eventually.
Does anybody has a 854 disk pack for me? I am looking for these as they are the only type fitting with that drive!

More pictures of the Control Data 854 Disk Storage Drive:

854 disk drive
                      in truck
The disk storage drive moved from the hangar and place inside the truck. A lot of dust has accumulated on the top cover over time and the front cover was missing.
The numerous disk drive logic boards of the 854 drive well accessible in the front of the drive. I need to verify, if no board is missing.
854 logic
854 power
                      supply, lower half
On the back-side of the drive is located a massive power supply with a power-on hours counter as it was typically done by CDC for computers and periperhals of that time. The counter stands at 33887.5 hours which is equivalent to 3,9 years of usage!
The CDC drive label found inside the drive. Apparently, this is a 854B drive, not a plain 854. Any idea, what the difference is?
854 drive