HP 33S User Manual

13–18 Programming Techniques
File name 33s-English-Manual-040130-Publication(Edition 2).doc Page : 388
Printed Date : 2004/1/30 Size : 13.7 x 21.2 cm
Loops with Counters (DSE, ISG)
When you want to execute a loop a specific number of times, use the
¹ ª
(
increment; skip if greater than) or
º «
(decrement; skip if less than or equal
to) conditional function keys. Each time a loop function is executed in a program, it
automatically
decrements or increments a counter value stored in a variable. It
compares the current counter value to a final counter value, then continues or exits
the loop depending on the result.
For a count–down loop, use
º «
variable
For a count–up loop, use
¹ ª
variable
These functions accomplish the same thing as a FOR–NEXT loop in BASIC:

variable = initial–value

final–value

increment
.
.
.

variable
A DSE instruction is like a FOR–NEXT loop with a negative increment.
After pressing a shifted key for ISG or DSE (
¹ ª
or
º «
), you will be
prompted for a variable that will contain the
loop–control number (described
below).
The Loop–Control Number
The specified variable should contain a loop–control number ±ccccccc.fffii, where:

±ccccccc is the current counter value (1 to 12 digits). This value changes with
loop execution.

fff
is the final counter value (must be three digits). This value does not change
as the loop runs.

ii is the interval for incrementing and decrementing (must be two digits or
unspecified). This value does
not change. An unspecified value for ii is
assumed to be 01 (increment/decrement by 1).
Given the loop–control number
ccccccc.fffii, DSE decrements ccccccc to
ccccccc — ii, compares the new ccccccc with fff, and makes program execution
skip the next program line if this
ccccccc
≤
fff.

HP 33S Specifications

General

Type	Scientific
Form factor	Pocket
Product color	Silver
Digits	10 digits
Display number of lines	2 lines
Keyboard type	Alphanumeric
Menus and prompts	Yes

Weight and Dimensions

Dimensions (WxDxH)	157 x 16 x 81 mm