HPs, How type this.

[rprosperi]

(08-13-2019 12:40 PM)ggauny@live.fr Wrote:  Hi all,

Newbe with HP35s, I wonder how type this kind of instructions :

for example :

Q002 SQ(REGY)-4*REGZ*REGX
Q011 -REGY/REGZ/2
Q017 2 REAL ROOTS CK=9C4D LN=12
Q018 PSE
Q019 CF 10
Q020 (-REGY+SQRT(REGX))/REGZ/2 CK=2A08 LN=25
Q021 (-REGZ-SQRT(REGY))/REGT/2 CK=E499 LN=25
Q022 RTN
Q023 SF 10
Q024 2 CPLX ROOTS
Q025 PSE
Q026 CF 10
Q027 (-REGY+SQRT(-REGX)*i)/REGZ/2 CK=1DFA LN=28
Q028 (-REGZ-SQRT(-REGY)*i)/REGT/2 CK=D662 LN=28

May be one could explain me.
Thank's in advance.

REGX/REGY/REGZ/REGT are used to access the 4 stack registers.

From the manual, Page B-7:

"To use these instructions, press [EQN] first. Then, pressing [Rv] produces a menu in
the display showing the X–, Y–, Z–, T–registers. Pressing [>] or [<] will move the
underline symbol, indicating which register is presently selected. Pressing [Enter]
will place an instruction into a program or equation that recalls the value of the
chosen stack register for further use. These are displayed as REGX, REGY, REGZ,
and REGT."

[Rv] is the roll down key.

If you don't have it, I'm sure the manual is available on HP's website.

This machine is well-known to have lots of bugs, but they are mostly obscure and typically don't affect general use. It is a nice RPN machine to learn and use, despite the bugs. One bug that can affect all users is that the checksum shown for a program is not always correct, however you can confirm a program you've typed-in is the same as your source by comparing them line-by-line, just like we have always done with older machines.