Natural logarithm of 2 [HP-15C/HP-42S/Free42 & others]

[JMBaillard]

Hi !
Here is an HP-41 version:

01 LBL "LN2"
02 1
03 STO 00
04 2
05 STO 01
06 1/X
07 LBL 01
08 RCL 01
09 RCL 00
10 ST/ Y
11 1
12 +
13 STO 00
14 *
15 ST+ X
16 STO 01
17 1/X
18 +
19 X#Y?
20 GTO 01
21 END

(32 bytes)

It takes about 13 seconds with an HP-41 which gives 0.6931471808
So, an error of about 2 E-10 ( and perhaps a little too slow )
But with free42, the result 6,931471805599453094172321214581773e-1
is returned in much less than 1 second.

Best regards.