what is 'J'? what is 'x729sj'? anon 09/07/26(Mon)15:07:46 No.1149

what is 'J'? what is 'x729sj'? anon 09/07/26(Mon)15:07:46 No.1149 [Reply]

Found this notebook in an abandoned house. Most pages are blank, but every few pages there's a single line written like some kind of log: 'Echo test #47: signal clear', 'Echo test #98: frequency shifted', 'Echo test #203: no response'. The last page just says 'J: x729sj detected'.