Matrix calculations on the HP-42S/Free42/DM-42

[JSBach]

Hi,

the HP-42S (and for compatibility reasons also Free42 and the DM-42)
has a IMO severe bug in the matrix editor:
It creates a "0" value in the Y register for no reason at all.

This considerably complicates the matrix calculations:
Every time you enter a matrix or look up a result you have to
(remember to) press [x<>y] and [RDN] to get the 0 out of the way
if you want to do further calculations.

How does one handle this in the best way?
You can store the matrices in variables, but eventually you want to see the results,
and then you have the "0" again.

Does anyone use matrix operations in the HP-42S/Free42/DM-42 at all?

Regards
JSBach

[Werner]

No you don't?
When you just browse the matrix and EXIT, the stack is not disturbed.
When you enter a new number in the first cell, the previous content is lifted up.
I will be the first to admit that EDIT should've disabled stack lift, as the -> etc. do;
but that is not the case, and it would mess up older programs to change it now.
Cheers, Werner

[JSBach]

Hello Werner,

thanks for the info!

Regards
JSBach

[DM48]

I ran into this issue yesterday and it was causing me all kinds of confusion. I found that simply hitting the -> and cycling all the way through and back to element 1:1, Stack Lift is disabled and I can key in my numbers without getting the zero on the Y stack.

This is exactly what Werner described above and it took me a minute to understand.

[Thomas Klemm]

(11-20-2020 08:51 AM)JSBach Wrote:  press [x<>y] and [RDN] to get the 0 out of the way

(05-30-2022 02:05 PM)DM48 Wrote:  hitting the -> and cycling all the way through and back to element 1:1, Stack Lift is disabled

Or then you use the ⬅ key (CLX) before entering the number in the first cell.

(11-20-2020 09:17 AM)Werner Wrote:  I will be the first to admit that EDIT should've disabled stack lift, as the -> etc. do;

I second that.