HP RPN SCIENTIFIC WP 34S Owner's Manual page 160

Thus take care with indirect addressing!
Example: Start with DECM, WSIZE 64, 2COMP, 0 STO 00, 2 STO 01, 10 STO 02 as
above. So RCL01 shall recall r02. Let us check. Key in:








All this is caused by the internal representation of numbers: While integers are simply
stored as such (allowing for n ≤ 1.84∙10
modes using 64 bits), standard floating point numbers are stored using a format as follows:
 Real zero is stored as integer zero, i.e. all bits cleared.
 The mantissa of a real number (also known as significand in this context) is
encoded in five groups of three digits. Each such group is packed into 10 bits
straight forward, meaning e.g. 555
3E7 . So the 15 rightmost decimal digits of the significand take the least significant
16
50 bits. Trailing zeroes are omitted, so the significand will be right adjusted.
 The most significant (64
 The remaining 13 bits are used for the exponent and the leftmost digit of the
mantissa. Of those 13, the lowest 8 are reserved for the exponent. For the top 5 bits
it gets complicated
00ttt
o
significand (0 – 7
the exponent;
11uut
o
the leftmost digit of the significand. If
will be the most significant bits of the exponent. If
are codes left for encoding special numbers (e.g. infinities).
In total, we get 16 digits for the mantissa and a bit less than 10 bits for the
exponent: its maximum is 10 1111 1111
obvious below, 398 must be subtracted from the value in this field to get the true
77
Don't blame us – this part follows the standard IEEE 754.
WP 34S Owner's Manual
Out of range Error
000000000001
2, 4 6684669589
th
) bit takes the sign of the mantissa.
77
: if they read ...
01ttt 10ttt
, , or
), and the top two bits will be the most significant bits of
10
t
then will be added to 1000
10.
just for verification: OK
h
A
turn to BASE 16
compare the table above
h
2
h
now this works in hex mode, too
h
223C
18
turn to DECM
0.
compare
indirection
fractional components. Otherwise
ISG/DSE loops all simply would
not work.
19 in UNSIGN or |n| ≤ 9.22∙10
= 10 0010 1100
10 2
ttt
then takes the leftmost digit of the
and the result (8
2
uu
reads 00, 01, or 10 then these two
(i.e. 767
2
Edition 3.1
the table
has to ignore
18
in the other
or 999 = 11 1110 0111
10
or 9 ) will become
10 10
uu
reads 11 instead, there
). For reasons becoming
10
Page 160 of 211
–
above
all
=
2