What is BS 4636-3 - Punched cards of 7-bit and 8-bit coded character sets about?
BS 4636-3 is the third part of the multiple series that defines the implementation of the ISO 7-bit and 8-bit coded character sets on punched cards. BS 4636-3 is intended for the general interchange of information among data processing systems, when using the ISO 7-bit or 8-bit coded character sets on 12-row punched cards as a data carrier.
Note: BS 4636-3 does not specify any redundancy nor does it define techniques for error control.
Who is BS 4636-3 - Punched cards of 7-bit and 8-bit coded character sets for?
BS 4636-3 on punched cards of 7-bit and 8-bit coded character sets is useful for:
- Data processing industries
- Manufacturers of punched cards devices
- Punched cards operators
- Suppliers of punched cards
- Installers of punched cards
Why should you use BS 4636-3 - Punched cards of 7-bit and 8-bit coded character sets?
Punched cards are an interchange document in which characters are represented in successive columns, each column having twelve possible punching positions.
BS 4636-3 specifies punching the twelve available positions of a given column of a punched card in the following way: positions 12, 11, 0, 9, 8, that are punched in any combination, giving 25 = 32 possibilities and only one of the positions 1, 2, 3, 4, 5, 6, 7 may be punched, which together with the NO PUNCH condition gives eight possibilities.
BS 4636-3 specifies the representation of 7-bit combinations and 8-bit combinations on 12-row punched cards. This representation is derived from, and compatible with, the code known as the “Hollerith Code”. This will ensure compatibility with a large proportion of existing punched card files.