HP 30b Business Professional Calculator - Manual (Page 89)

Programming 81
Tests and Jump Functions
When creating a program, there is often a need for the conditional execution of an instruction
based on a specific condition, as well as the repetition of a set of instructions.
This is handled on the HP 30b using the GOTO, LBL (label) and Test instructions. LBL is an
instruction that does not do anything by itself, but it acts as a marker for Jump instructions.
1. To enter a label or GOTO instruction, press and hold
:
and simultaneously press the
GOTO, GOTOT, or GOTOF key, then release both keys.
2. Type a number between 00 and 99 (for numbers smaller than 10, you must type the 0
first, such as 03).
3. For example, (HOLD) creates label 03 in your program. You can
then use a GOTO 03 instruction to jump to that label from any location in your program
to the position of the label. GOTOT (Go To If True) and GOTOF (Go To If False) will only
jump if the current displayed number is non-0 (true) for GOTOT or 0 (false) for GOTOF.
Used together, these instructions allow you to create programs like the following:
8=
LBL 01
DISP 5
- 1=
GOTOT 01
STOP
Use the following keystrokes to enter the program:
1.
(HOLD)
2.
(HOLD)
3.
(HOLD)
4.
(HOLD)
. This program has 13 bytes, and the checksum is 234. This
program counts from eight to zero displaying each number 1 second.