The HP 48 object listed below in ->ASC form is a high-performance polynomial root finder. Those of you who remember the HP 71B Math Pac will recognize this as the same as the PROOT command from that Pac; it is in fact the same assembly-language code, given an RPL front end to operate in the HP 48.
Found on https://www.hpmuseum.org/forum/thread-10967-post-160700.html#pid160700
See also http://www.jeffcalc.hp41.eu/emu71/mathrom.html#src for the uncommented source code of PROOT and other functions of the HP71B math pack.