Rigid Disks

 
HP 13356A Disk Pack, 120Mb, used in the HP 7925 drive. The pack has 5 platters (9 data heads and a servo head). Here's a picture of the 7925 next to a HP3000 Series II. Here's another view from the HP Computer Museum. The 7925 was introduced in 1978.
 
HP 97935 Disk Pack, 404Mb, used in the HP 7933 and 7935 drives. The pack has 7 platters (13 data heads and a servo head). This particular pack was used in a HP9000 system. Here's a picture of a 7935, courtesy of the HP Computer Museum. The 7935 was introduced in 1983.
 
Wang 76MB cartridge disk pack, 9", used on CDC 9710-80 RSD drives, Wang 2267V-1 and others. Inside the cartridge are 3 platters, with 5 data surfaces and one servo surface. When inserted vertically into the drive, a plastic shutter opens to allow the heads access to the platters. Circa 1982.
 
Nashua 4473 Disk Pack, 300Mb, 14". The pack has 12 platters, 10 of which are used (19 data heads and 1 servo head). It was commonly used with drives such as the CDC 9766 and the DEC RM05. These drives were in common use around 1980-1982.
 
Nashua 4462 Disk Pack, 80Mb, 14". The pack has 5 platters, 3 of which are used (5 data heads and 1 servo head). It was commonly used with drives such as the CDC 9762, DEC RM02 and RM03, Data General 6067 and 1143, and Burroughs B9484.
 
DEC RK07K-DC disk pack, used with the DEC RK07 removeable cartridge drive. This cartridge has two platters with three recording surfaces and a servo surface, and held approximately 28MB of data. The RK07 was commonly used on PDP-11 and VAX systems, starting around 1976.
 
DEC RK06K-DC disk pack, used with the DEC RK06 removeable cartridge drive. This cartridge has two platters with three recording surfaces and a servo surface, and held approximately 14MB of data. The RK06 was commonly used on PDP-11 systems, starting around 1976.
 
Memorex RK05 disk pack, used with the DEC RK05 removeable cartridge drive. This cartridge has a single platter with two recording surfaces, and held approximately 2.5MB of data. The RK05 was commonly used on PDP-8/E PDP-11 systems, starting around 1972.
 
DEC RL02K-DC disk pack, used with the DEC RL02 removeable cartridge drive. This cartridge has a single platter with two recording surfaces, and held approximately 10MB of data. The RL02 was commonly used on PDP-11 systems, starting around 1978.
 
Disk head carriage, head and voice coil assembly circa 1974 from a CDC 9762 or derivative drive such as the DEC RM02 or RM03. There are six heads: 5 data and 1 servo. The cable is broken from the servo head.
 
Sony Magneto-Optical cartridge disk, 600MB capacity (300MB each side). The cartridge had to be flipped over to access the B side. The cartridge is about the same size as a CD-ROM in its carrier, and twice as thick. MO drives were introduced in the late '80s and the larger drives were all SCSI-based. A combination of laser and electromagnetic head is used to write information to the disc, and the laser alone (at lower power) is used to read the information.

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Last updated on Friday, May 22, 2020