The algorithm was published by Dennis Allison in "A design philosophy for microcomputer architectures", Computer (Volume: 10, Issue: 2, February 1977), https://

The algorithm was published by Dennis Allison in "A design philosophy for microcomputer architectures", Computer (Volume: 10, Issue: 2, February 1977), https://doi.org/10.1109/C-M.1977.217645 https://doi.org/10.1109/C-M.1977.217645 Curiously, the article discusses design goals for microcomputers at a high level. The hex to ASCII algorithm was a random example of the gap between compilers and machine code. Allison had done a bunch of work with Knuth on decimal arithmetic, so he probably had this example at his fingertips.