Telepen
Encyclopedia
Telepen is a name of a barcode
symbology designed in 1972 in the UK to express all 128 ASCII characters without using shift characters for code switching, unlike Code 128
, while only using two different widths for bars and spaces. Unlike most linear barcodes that specify the encodings for each representable character, Telepen only defines 4 basic bar-space modules:
The scheme allows to encode all even parity bytes, and can even be used for a continuous bitstream.
A Telepen symbol includes a check digit that is calculated as the value that when added to the modulo 127 sum of the encoded data would make 127.
Barcode
A barcode is an optical machine-readable representation of data, which shows data about the object to which it attaches. Originally barcodes represented data by varying the widths and spacings of parallel lines, and may be referred to as linear or 1 dimensional . Later they evolved into rectangles,...
symbology designed in 1972 in the UK to express all 128 ASCII characters without using shift characters for code switching, unlike Code 128
Code 128
Code 128 is a very high-density barcode symbology. It is used for alphanumeric or numeric-only barcodes. It can encode all 128 characters of ASCII and, by use of an extension character , the Latin-1 characters defined in ISO/IEC 8859-1...
, while only using two different widths for bars and spaces. Unlike most linear barcodes that specify the encodings for each representable character, Telepen only defines 4 basic bar-space modules:
- narrow bar-narrow space for bit 1
- wide bar-narrow space for bit sequence 00
- wide bar-wide space for bit sequence 010
- narrow bar-wide space for bit sequence 01 or 10 (the meaning alternates, so 01110 is encoded as 01 1 10 where the first and the third module is the same).
The scheme allows to encode all even parity bytes, and can even be used for a continuous bitstream.
A Telepen symbol includes a check digit that is calculated as the value that when added to the modulo 127 sum of the encoded data would make 127.