Floppy Drives

Early Vertical Drives

Tandon Drives

"The Tandon [disk] drives suck. Excuse my language. But 40 years later, the amount of pain they caused still reverberates. They were not well-made. The guys in support spent a lot of time with dealers, like a technician in Boise, explaining how to adjust the armature. And that was not their skill set. They were there mainly for how to use WordStar, how to use Perfect Filer."
(Interview with Marshall Mosley)

The Tandon Corporation was a small, specialized business back in 1979, making the delicate devices that record bits of information and retrieve them from computer files known as disk drives.

Then the president of the Tandy Corporation, spotting a chance to cut his material costs, persuaded Sirjang Lal Tandon, founder of Tandon, to add a motor and chassis to the recording heads, and go into the disk drive business on his own. To get things going, Tandy ordered 50,000 of the units for about $12 million, and used them in its first Radio Shack personal computer.

It was a step that Mr. Tandon, a burly, one-time mechanical engineer at the International Business Machines Corporation, has not regretted. Tandon - which is not a part of Tandy - is now the world's biggest independent producer of disk drives for small computers and word processors, and Mr. Tandon, known by his nickname, Jugi, is one of the nation's wealthier industrialists. ...

His disk drives now range from $50 to $1,000. ...

The Tandon disk drive is used in microcomputers produced by I.B.M., Radio Shack, Commodore International, Victor, Digital Equipment, Wang Laboratories and Kaypro, among others. ...

"Right now, Tandon is one of the main reasons why we are able to get out into the marketplace and compete," said C.E. Smith, Kaypro's director of purchasing.

His company in Solana Beach, Calif., is considering doubling the production rate of its three Kaypro models to a total of 20,000 a month in August. It also is planning a $200 price cut for its most popular unit, the Kaypro II, to $1,395 by September - if Tandon delivers a more compact disk drive later this summer. ...

While Mr. Tandon has used a lean organization whose performance is rated highly, it has not been perfect. Mr. Smith of Kaypro said, for example, that Tandon has slipped a bit on delivery of the thin disk drives due for assembly in September. "They have been remiss, but have cut some prices" to compensate, he said.
(New York Times, June 25, 1983)

Tandon TM100-1

The Tandon TM100-1 is the original drive at the beginning of the Kaypro II production. They are Double Density, Single Sided drives that hold about 250KB of raw data. That translates to a drive capacity of about 180KB. (I usually see the TM100-1A variant.)

The majority of Tandon Drives from the Kaypro factory usually do not have the under tab labels.	Here is an under tab label for the TM100-1A that could be from the factory.

Example Replacement Tandon Drives

This drive appears to be a replacement in an early machine. Being a Tandon TM101-4 it is a Quad Density, Double Sided Drive capable of storing up to 1000KB of raw data (More like 800KB of usable data). I suspect the Monitor ROM has been upgraded in the system.

The standard Tandon Drives from the Kaypro factory usually do not have the under tab labels.