Editing Punched tape (section)

=== Data transfer for ROM and EPROM programming ===
In the 1970s through the early 1980s, paper tape was commonly used to transfer binary data for incorporation in either mask-programmable [[read-only memory]] (ROM) chips or their erasable counterparts [[EPROM]]s. A significant variety of encoding formats were developed for use in computer and ROM/EPROM data transfer.<ref name="Data I/O Corporation"/> Encoding formats commonly used were primarily driven by those formats that EPROM programming devices supported and included various ASCII hex variants as well as a number of proprietary formats.

{{anchor|BNPF|BPNF|BHLF|B10F}}A much more primitive as well as a much longer high-level encoding scheme was also used, [[BNPF]] (Begin-Negative-Positive-Finish),<ref name="Intel_1974"/><ref name="Feichtinger_1987"/> also written as [[BPNF]] (Begin-Positive-Negative-Finish).<ref name="Intel_1977"/> In BNPF encoding, a single [[byte]] (8 bits) would be represented by a highly redundant character framing sequence starting with a single uppercase ASCII "B", eight ASCII characters where a "0" would be represented by a "N" and a "1" would be represented by a "P", followed by an ending ASCII "F".<ref name="Intel_1974"/><ref name="Intel_1977"/><ref name="Feichtinger_1987"/> These ten-character ASCII sequences were separated by one or more [[whitespace character]]s, therefore using at least eleven ASCII characters for each byte stored (9% efficiency). The ASCII "N" and "P" characters differed in four bit positions, providing excellent protection from single punch errors. Alternative schemes named BHLF (Begin-High-Low-Finish) and B10F (Begin-One-Zero-Finish) were also available where either "L" and "H" or "0" and "1" were also available to represent data bits,<ref name="GP_1984"/> but in both of these encoding schemes, the two data-bearing ASCII characters differ in only one bit position, providing very poor single punch error detection.