AIP and big numbers

Post here to share useful tips and tricks, to ask questions about using your DM42 or to report software-related problems
Post Reply
Posts: 4
Joined: Fri Aug 09, 2019 6:03 am

AIP and big numbers

Post by Jvi » Thu Nov 28, 2019 2:33 pm

The function AIP behaves strangely when you try to put a big number in the alpha register.

Try calculating factorial 100, then AIP the result, and finally AVIEW the Alpha value. You will see 44 zeros.
What happens, is that the AIP function starts at the wrong end (least significant digit) and work its way towards the most significant digit, but stops when the alpha string is 44 characters long. Since the calculated result is only displayed with the 33 most significant digits, and the result is a number with 158 digits, it never gets to other digits than zero. If the number is bigger than 1.00E43, the most significant digits will be cut off, so here all the significant digits are cut off.
This behavior is not unique for the DM42.
The HP42 has the same problem, so i guess the feature (bug? error?) is well known to veteran HP42 users.

User avatar
Posts: 152
Joined: Wed May 24, 2017 6:26 pm
Location: Germany

Re: AIP and big numbers

Post by Guenter » Thu Nov 28, 2019 9:33 pm

I don't think it's a bug or error. Manual pg. 133 "When the Alpha register fills up, characters at the left end of the register (the "oldest" characters) are lost to make room for the new data."

I guess it doesn't matter whether new characters are appended or the new string is to long itself.

DM42 SN:00004 and SN:00184 -- DM41X SN:00013

Post Reply