[Inyo-Mono]

Don’t recall who made it, but remember using a computer at work in the late 1980s, early ‘90s that used a cassette tape as a hard drive.

[Rebelbase]

The Timex Sinclar 1000 with a whopping 1KB of RAM came out in the early 80's and used a cassette tape for data storage.

[Duchess47]

In the late 60’s I worked for Siliconix. We had a computer that we used punch cards and paper tapes in. Size of a large refridgerator. Seems 100 years ago.

[Mastador1]

Commodore made computers that used cassette storage, until they made the Amiga..............then they were gone.

[Desron13]

That would be the Timex Sinclare Z80. I put one together as a kit from mail order. You could expand the memory to a whopping 16K with a rather expensive memory upgrade.