(06-01-2016 10:52 AM)hp41cx Wrote: [ -> ]08 93 .
09 00 0
10 01 1
11 82 HIR
12 42 42
OK!
In a real TI-58C.
Very interesting. OK, the 58C has a ROM that's different from the 59. Since it appeared quite a while after the 58/59 were released this could be a kind of bugfix.
I did some more tests on TI59.EXE for Windows, using a short test program:
Code:
000 76 LBL
001 11 A
002 32 x<>t
003 01 1
004 82 HIR
005 01 01
006 32 x<>t
007 82 HIR
008 41 41
009 82 HIR
010 11 11
011 92 RTN
This loads the first HIR with 1 and multiplies this by the input before the register is finally recalled. So if everything works as expected the output should match the input.
Here is what I got:
Code:
input output
---------------------
1 [A] 1
3 [A] 3
4,5 [A] 4,5
635,7 [A] 635,7
-17 [A] -17
0,1 [A] 10
0,0123 [A] 123
0,00005 [A] 500000
So in numbers with negative exponent the sign of the latter is ignored. 0,1 = 1E-1 becomes 1E+1 = 10, and 5E-5 becomes 5E+5 = 500000.
But wait, it's getting even better:
Code:
input output
------------------------------
100000 [x^2] 1 10
[1/x] ,0000000001
[÷] 10 [=] 1 -11
[A] 1 -11
[x^2] 1 -22
[A] 1 -22
So very small values are handled correctly while for larger ones the sign of the exponent is ignored. Further tests showed that the limit seems to be 5E-11. See below.
Now let's enter values below 1 in EE mode.
Code:
input output
----------------------
1 EE -1 [A] 1 -01
5 EE -5 [A] 5 -05
3 EE -99 [A] 3 -99
So in EE mode everything sees to work fine!
Now let's try ENG mode
Code:
2nd ENG
input output
---------------------
123 [A] 123 00
1234 [A] 1,234 03
0,123 [A] 123 -03
0,00005 [A] 50 -06
INV ENG 0,00005
So ENG mode seems to work fine, too.
All in all it turned out that the problem with the ingored exponent sign only occured
if the number was displayed without an exponent. That's why 5E-11 still shows the problem (display is rounded to ,0000000001) while 4,99E-11 has no problems (display is 4,99 -11). Is this strange, or what?
BTW, I just discovered some other odd behaviour, not sure whether it's the same on a real hardware 58/59/58C:
Code:
input display
---------------------
123 EE 15 = 1,23 17
EE 5 1,23 75
9 1,23 59
= 1,23 59
EE 0 1,23 90
3 1,23 03
= // this was originally missing
INV EE 1230
So even after a number has been entered or calculated, pressing EE seems to re-edit the exponent.
Dieter