HP67 Date of Easter
04-16-2021, 06:00 PM
Post: #1
 HP67Child Junior Member Posts: 5 Joined: Apr 2021
HP67 Date of Easter
Hi

Is anybody interested in a HP67 program calculating the date of Easter of (almost) every given year?

HP67Child
04-19-2021, 12:48 PM
Post: #2
 Jake Schwartz Senior Member Posts: 355 Joined: Dec 2013
RE: HP67 Date of Easter
Hi,

For what it is worth, Hugh Kenner (PPC member #103) posted a 224-step HP67 Easter program in the PPC Journal in Volume 5 Number 4 Page 7 (May 1978).

Jake
04-19-2021, 02:33 PM
Post: #3
 Gene Moderator Posts: 1,378 Joined: Dec 2013
RE: HP67 Date of Easter
Here it is. Let's compare the two. Always good to see how an approach to a problem can be different.

HP67Child... your program may do things better than this one. Let's see. :-)

Gene

Attached File(s)
PPC Journal V5N4P8 - Easter Program.pdf (Size: 181.48 KB / Downloads: 65)
05-06-2021, 11:22 AM
Post: #4
 HP67Child Junior Member Posts: 5 Joined: Apr 2021
RE: HP67 Date of Easter
Hi,

The algorithm origitates from http://www.assa.org.au/edm.html#Computer

I've slightly changed the code so that you can read it more easily. E.g. I used "ENTER", "/" and "x<->y".
It works in the following way:
Write a year as a 4-digit number. Press A. The result is in the form M.DD (Month.Day) which is the Easter Sunday of the year.
Exemples:
2021
A
4.04
1967
A
3.26
2000
A
4.23
The year must be between 1583 and 4099. Otherwise the program gives -1.

HP67Child

Attached File(s)
HP67_Date_of_Easter.txt (Size: 6.17 KB / Downloads: 32)
05-06-2021, 11:03 PM
Post: #5
 Joe Horn Senior Member Posts: 2,004 Joined: Dec 2013
RE: HP67 Date of Easter
(05-06-2021 11:22 AM)HP67Child Wrote:  It works in the following way: ...

Your 287-step program doesn't fit into my 224-step HP-67.

<0|ɸ|0>
-Joe-
05-07-2021, 03:02 AM
Post: #6
 rprosperi Super Moderator Posts: 6,362 Joined: Dec 2013
RE: HP67 Date of Easter
(05-06-2021 11:03 PM)Joe Horn Wrote:
(05-06-2021 11:22 AM)HP67Child Wrote:  It works in the following way: ...

Your 287-step program doesn't fit into my 224-step HP-67.

It would appear the emulator the author used was not authentic in at least one way...

--Bob Prosperi
05-07-2021, 06:19 AM
Post: #7
 HP67Child Junior Member Posts: 5 Joined: Apr 2021
RE: HP67 Date of Easter
I do apologize.
I don't have a real HP67 (I'd love to have one), but I instead use an Android emulation that appears not to have this size limit.
I promise to try to shrink the program (if I had eough time to do the task).

The format of the code in the attached file is appropriate for you?

Once more sorry
HP67Child
05-07-2021, 06:27 AM
Post: #8
 HP67Child Junior Member Posts: 5 Joined: Apr 2021
RE: HP67 Date of Easter
But please help me. What is the real size limit? My faint memory about a real HP67 is that the limit is 255. Am I wrong? Is the real limit 224?

Thank you
HP67Child
05-07-2021, 08:29 AM
Post: #9
 Joe Horn Senior Member Posts: 2,004 Joined: Dec 2013
RE: HP67 Date of Easter
(05-07-2021 06:27 AM)HP67Child Wrote:  But please help me. What is the real size limit? My faint memory about a real HP67 is that the limit is 255. Am I wrong? Is the real limit 224?

Yes, the physical HP-67 and HP-97 have a maximum of 224 program steps.

<0|ɸ|0>
-Joe-
05-07-2021, 09:48 AM
Post: #10
 HP67Child Junior Member Posts: 5 Joined: Apr 2021
RE: HP67 Date of Easter