HP-15C CE woes: 1 bug, 2 limitations, 3 questions

[Voldemar]

(08-09-2023 09:52 AM)ThomasF Wrote:  1)
If the resulting HEX-value contains 'E' or 'F' the DEC-value is wrong.

DEC mode if in HEX mode number contains:
One E or F as last digit
E -> 08 = 14 - 6×16^0
F -> 09 = 15 - 6×16^0
1E -> 24 = 30 - 6×16^0
1F -> 25 = 31 - 6×16^0
2E -> 40 = 46 - 6×16^0
2F -> 41 = 47 - 6×16^0
9E -> 152 = 158 - 6×16^0
9F -> 153 = 159 - 6×16^0
10E –> 264 = 270 - 6×16^0
111E -> 4376 = 4382 - 6×16^0
--------------------------------------
One E or F as secodn from end digit
E0 -> 128 = 224 - 6×16^1
24F1 -> 9361 = 9457 - 6×16^1
--------------------------------------
One E or F as second from end digit and one E or F as last digit
4EF -> 1161 = 1263 - 6×16^0 - 6×16^1
--------------------------------------
One E or F as third from end digit
1E14 -> 6164 = 7700 - 6×16^2
.....................................................
etc.

Each E or F in the number causes 6×16^n to be subtracted from the correct result.
n=0 if E or F last digit in number
n=1 if E or F is the second digit from the end in the number
n=2 if E or F is the third digit from the end in the number
and so on