In the late 1970s, Tandon developed direct equivalents to Shugart floppy drives, and is credited with the invention of DS/DD (double-sided, double-density) versions[4][5] which became its primary product in the early 1980s.

Until 1985, Tandon were the sole supplier of floppy drives for IBM PCs, initially the same single-sided unit used in the TRS-80, then the newer double-sided TM-100-2.

[3] In the mid-1980s, Tandon introduced a line of hard disk drives, making several models of the same basic design with a P-shaped top cover and a pinion rack stepper motor off to the side.

[2] A major decline in North American computer sales during 1984–85 as well as competition from Japanese and Taiwanese manufacturers proved difficult for the company.

[2] Tandon in April 1987 purchased hard disk drive maker Atasi Corporation for $5 million in stock.