> Each card was a physical medium that contained a limited amount of data, typically a few hundred bytes Standard IBM punch cards were 80 columns by 12 rows so

> Each card was a physical medium that contained a limited amount of data, typically a few hundred bytes Standard IBM punch cards were 80 columns by 12 rows so they could theoretically hold 960 bits. In practice they contained up to 80 characters EBCDIC, an 8-bit encoding so around 80 "bytes".