Ah, fond memories of first learning about Busy Beavers in A.K.Dewdney’s column in the Spanish edition of Scientific American (“Investigación y Ciencia”) as a kid:
<a href="https://www.investigacionyciencia.es/revistas/investigacion-y-ciencia/monumento-azteca-161/una-trampa-computarizada-del-castor-afanoso-la-ms-productiva-de-las-mquinas-de-turing-2062" rel="nofollow">https://www.investigacionyciencia.es/revistas/investigacion-...</a><p>I made my own Turing Machine emulator for my Commodore 64 to play with this, using the screen memory as tape to speed it up: modifying the tape was immediately reflected on the screen with no other processing needed, saving precious cycles.<p>That made for quite a small tape, but allowed even my crude BASIC implementation to run fast, or so I remember it.<p>The original article in English appeared in the August 1984 magazine, and the translated ones in October of that same year:
<a href="https://www.jstor.org/stable/24969427" rel="nofollow">https://www.jstor.org/stable/24969427</a><p>If you can read Russian or Italian, you can find the full article here:<p>Russian: <a href="https://gudleifr.forum2x2.ru/t98-topic#1254" rel="nofollow">https://gudleifr.forum2x2.ru/t98-topic#1254</a><p>Italian: <a href="https://archive.org/details/divertirsiconilcalcolatore/page/n85/mode/2up" rel="nofollow">https://archive.org/details/divertirsiconilcalcolatore/page/...</a><p>I quote the historical introduction from the English version:<p>> “<i>With the possible exception of bees, beavers are the busiest animals alive. All day they ply quiet northern waters bringing twigs and branches to their dam. It was undoubtedly this behavior that led Tibor Rado of Ohio State University to name a certain Turing-machine problem the Busy Beaver Game. In the early 1960’s Rado wondered how many 1’s a Turing machine could be made to print before it halted. Specifically, if a Turing machine with n possible states begins to work on a tape filled with 0’s, what is the largest number of 1’s it can print on the tape before coming to a stop? The answer is known for n = 1, n = 2, n = 3, and n = 4 but not for n = 5 or for any value of n grater than 5.</i>”