ENG mode, n+1?

[Thomas Klemm]

(01-18-2014 02:19 AM)Sylvain Cote Wrote:  PS: if you need more tests let me known, I have all the models.

What might be interesting is to compare HP-25, HP-29 in ENG n mode with a later model (say HP-32E) in ENG n+2 mode. Display the numbers 1.23456789, 12.3456789, 123.456789, ...
It's interesting to see what happens with the HP-32E in ENG 0 and ENG 1 mode: the amount of digits in the display change when 1.23456789 is multiplied by 10, 100, ...

ENG 0

Code:


1.23456789: [1.       00]
12.3456789: [10.      00]
123.456789: [100.     00]
1234.56789: [1.       03]

ENG 1

Code:


1.23456789: [1.2      00]
12.3456789: [12.      00]
123.456789: [120.     00]
1234.56789: [1.2      03]

This doesn't happen when \(n\geqslant2\):

ENG 2

Code:


1.23456789: [1.23     00]
12.3456789: [12.3     00]
123.456789: [123.     00]
1234.56789: [1.23     03]

Only the decimal point gets shifted around. Thus the complicated cases of the ENG display format are avoided in the HP-25.

(01-17-2014 03:05 AM)Thomas Klemm Wrote:  But still sounds arbitrary. Why "after the first three"?

Maybe there wasn't enough place in the ROM to implement the special cases.

Cheers
Thomas