- IBM 80 column – rectangular holes, 80 characters/card (this is the card most people are familiar with)
- Remington Rand/UNIVAC – round holes, 90 characters/card
- IBM 96/128 column – small round holes, 96 or 128 characters/card (much smaller than 80 column card)
- Powers-Samas – round holes, 40 characters/card
- etc.
They were eventually replaced as technology superseded them and made them obsolete. They were very low density data storage by today’s standards. A typical box of 2000 cards occupies about 0.22 cubic feet and can store 160,000 characters. Compare this to a small capacity USB thumb drive which occupies maybe a cubic inch and can store 8 billion characters. To store the same 8 billion characters on punchcards you would need about 11,000 cubic feet of warehouse space. The USB drive is directly read/write accessible by your computer, the punchcards are not you need a reader/punch connected to the computer which you will have to manually load and unload cards every few thousand. Once punched cards are read only, you can’t unpunch a hole. Cards cannot be accessed by filename and must be read or punched in sequence. etc.