Mini-challenge: Fast F(93) on HP-16C

[Joe Horn]

(08-07-2023 06:04 AM)ThomasF Wrote:  This is my attempt.
Just enter n then GSB A

Code:

001 LBL A
002 X=0?
003 R/S
004 1
005 X=Y?
006 R/S
007 -
008 STO I
009 0
010 LASTx
011 LBL 0
012 ENTER
013 ENTER
014 RUP
015 +
016 DSZ 
017 GTO 0

Cheers,
Thomas

Cool! This gets the right result for F(93) in 50 seconds on an original HP-16C in DEC UNSIGNED mode with WSIZE=64. Unfortunately, it also reveals a bad bug in the 16C mode of the 15C CE, which makes DEC mode useless, namely, digits are often displayed incorrectly, even if the internal value is correct. Example: F(93) is correctly returned in less than 1 second, but it's unreadable because most of its digits are displayed as wrong digits. Pressing the HEX key displays the result in hex, which can be verified to be equal to F(93).