HP-35s Roll down question

[Dieter]

(03-04-2019 12:43 AM)Kevin Braun Wrote:  I am a new owner of an HP-35s and am entering a Moon Lander program:
http://www.hpmuseum.org/software/35moonla.htm

and line: C027 Rv

has me a bit confused, When I am entering the line and I press Rv, I get:
X Y Z T
0.0

First of all, just to be sure: you do not have to enter "Rv" (letters R and V). "Rv" is a common way of writing R↓, the roll down key. So you do not press EQN and enter "R" and "V". Just press the [R↓] key instead. Edit: looking at the subject line you obviously already knew that. #-)

What you described happens in equation mode, i.e. you have pressed the EQN key before. In this case R↓ lets you select one of the displayed registers X...T. You will see "C027 _" and the EQN annunciator on top of the display is on.

Simply delete that line so that you see C026 STO+V again. Then press the [R↓] key. This will insert a R↓ command. That's all.

Looking at the program I'd say that the R↓ line is not even required:

Code:

.... ...
C023 RCL V
C024 +
C025 STO H
C026 RCL A
C027 STO+ V
C028 1
C029 STO+ T
C030 VIEW T
C031 PSE
C032 GTO M001

This should work as well.

Dieter