DC100

The DC100 tape format and drive was developed by Hewlett-Packard and introduced as a data storage mechanism for the HP-9825 programmable calculator. The DC100 tape cartridge was a scaled-down version of the DC300 cartridge pioneered by 3M, and represents an early version of what is now referred to as the QIC Mini Cartridge

This format was used in the HP desktop calculator/computer systems of the late 1970s and early 1980s, including the 9815, 9825, 9845 and HP series 80. It was also used in the HP 2640 series of computer terminals.

The DC150 cartridge, a variation with slightly higher capacity, was used in Digital Equipment Corporation's DECtape II drives.

The DC100 tape is based on the 1972 patent number U.S. Patent 3,692,255.

DC100:

3M manufacturing secrets.

HP improvements on the 3M design;

3M developed the DC300 tape cartridge for loading programs into AT&T’s electronic switching systems that were becoming the backbone of the world’s phone system in the 1970s.

QIC minicartridges evolved its capacity from 250 kByte, 40, 80, 120, to a final 250 MByte. QIC-3230 tapes have a 20 Gbyte maximum.

...
Wikipedia