Transcript Check this out!!!!

Check this out!!!!
How we tell the computer what
to do:
Programmer writes code that looks
alot like english.

Eg: If (intRate > 100)
Each command is broken into
a CPU command (machine code)
to be executed:
Assembler breaks it into
closer machine code:
iload intRate
Bipush 100
if_icmpgt intError
21 40 16 100 163 240
Problem maybe?
CPU commands
Intel 21 = iloadC
IBM 21 = shunt
Apple 21 =
bipush
Sun 21 = spool
AMD 21 = halt
This is why Intel software won't run on apple, it thinks it asked for iload,
and actually does bipush = big crash.
Java Virtual Machine (JVM)
Java Virtual Machine =
translator.
JVM gets instruction, then converts to
hardware needs.
JAVA iload = 47
J
A
V
A
VI
R
T
U
A
L
M
A
C
H
I
N
E
Intel 21 = iload
Sun 28 = iload
Apple 12 = iload
AMD 4 = iload
IBM 17 = iload
Advantages of programming with Java:
 Simple
 Safe
 Platform-independent ("write once,
run anywhere")
 Rich library
 Designed for the internet
Information on Java:
Task:
Open up a word document and answer the following questions:
Q1a: What is machine code? Find a suitable definition on the internet.
Q1b:Describe the programming process. Make sure to outline how information is
broken down from High Level coding all the way to Machine Code numbers.
Q2: Why is the JVM piece needed in the programming process?
Q3: Why was Java embraced so well?
Q4: Why is Java suitable for beginners?
Q5: When you open a website, what is the process of getting the content to
your screen?
Q6: Give the three reasons Java is not perfect.
Q7: Go on the internet and research on what requirements are for becoming a
Java programmer. What are the salaries like? Are they in demand right now?
What are Java evangelists?
Q8: Save the file in your ICS 3 folder Unit 1 as MachineCodeAndJVM.doc.