HP 35s Scientific Calculator - Manual (Page 161)

Base Conversions and Arithmetic and Logic 11-3
you can use  menu to enter base-n sign b/o/d/h following the operand to
represent 2/8/10/16 base number in any base mode. A number without a base
sign is a decimal number
Note:
In ALG mode:
1. The result’s base mode is determined by the current base mode setting.
2. If there is no active command line (there is no blinking cursor on line 1),
changing the base will update line 2 to be in the new base.
3. After pressing  or changing the base mode, calculator will
automatically add a current base sign b/o/h following the result to represent
base 2/8/16 number in line 2.
4. To edit expression again, press Ö or Õ
In RPN mode:
When you enter a number in line 2, press  , and then change the base
mode, the calculator will convert the base of the numbers in line 1 and line 2, and
the sign b/o/h will be added following the number to represent base 2/8/16.
To view the next screen’s content in line 2, press Ö or Õ to change the
screen.
 ()

The entire binary number does
not fit. The annunciator
indicates that the number
continues to the right.
Õ 

Displays the rest of the number.
The full number is
10010011111111
b
.
Ö

Displays the first 14 digits
again.
 ()

Restores base 10.