<s>
The	O
Parallax	O
P8X32A	O
Propeller	O
is	O
a	O
multi-core	B-Architecture
processor	I-Architecture
parallel	B-Operating_System
computer	I-Operating_System
architecture	O
microcontroller	B-Architecture
chip	O
with	O
eight	O
32-bit	O
reduced	B-Architecture
instruction	I-Architecture
set	I-Architecture
computer	I-Architecture
(	O
RISC	B-Architecture
)	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
CPU	O
)	O
cores	O
.	O
</s>
<s>
The	O
Propeller	B-Architecture
microcontroller	I-Architecture
,	O
Propeller	O
assembly	B-Language
language	I-Language
,	O
and	O
Spin	O
interpreter	B-Application
were	O
designed	O
by	O
Parallax	O
's	O
cofounder	O
and	O
president	O
,	O
Chip	O
Gracey	O
.	O
</s>
<s>
The	O
Spin	O
programming	O
language	O
and	O
Propeller	O
Tool	O
integrated	B-Application
development	I-Application
environment	I-Application
(	O
IDE	O
)	O
were	O
designed	O
by	O
Chip	O
Gracey	O
and	O
Parallax	O
's	O
software	B-Application
engineer	O
Jeff	O
Martin	O
.	O
</s>
<s>
On	O
August	O
6	O
,	O
2014	O
,	O
Parallax	O
Inc	O
.	O
released	O
all	O
of	O
the	O
Propeller	O
1	O
P8X32A	O
hardware	O
and	O
tools	O
as	O
open-source	B-Application
hardware	O
and	O
software	B-Application
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
3.0	O
.	O
</s>
<s>
This	O
included	O
the	O
Verilog	B-Language
code	O
,	O
top-level	O
hardware	O
description	O
language	O
(	O
HDL	O
)	O
files	O
,	O
Spin	O
interpreter	B-Application
,	O
PropellerIDE	O
and	O
SimpleIDE	O
programming	O
tools	O
and	O
compilers	O
.	O
</s>
<s>
Each	O
of	O
the	O
eight	O
32-bit	O
cores	O
(	O
termed	O
a	O
cog	O
)	O
has	O
a	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
CPU	O
)	O
which	O
has	O
access	O
to	O
512	O
32-bit	O
long	O
words	O
(	O
2KB	O
)	O
of	O
instructions	O
and	O
data	O
.	O
</s>
<s>
Self-modifying	B-Application
code	I-Application
is	O
possible	O
and	O
is	O
used	O
internally	O
,	O
for	O
example	O
,	O
as	O
the	O
boot	B-Application
loader	I-Application
overwrites	O
itself	O
with	O
the	O
Spin	O
Interpreter	B-Application
.	O
</s>
<s>
Subroutines	O
in	O
Spin	O
(	O
object-based	O
high-level	B-Language
code	O
)	O
use	O
a	O
call-return	O
mechanism	O
requiring	O
use	O
of	O
a	O
call	O
stack	B-Application
.	O
</s>
<s>
Assembly	O
(	O
PASM	O
,	O
low-level	O
)	O
code	O
needs	O
no	O
call	O
stack	B-Application
.	O
</s>
<s>
Access	O
to	O
shared	O
memory	O
(	O
32KB	O
random-access	B-Architecture
memory	I-Architecture
(	O
RAM	B-Architecture
)	O
;	O
32KB	O
read-only	B-Device
memory	I-Device
(	O
ROM	B-Device
)	O
)	O
is	O
controlled	O
via	O
round-robin	B-Algorithm
scheduling	I-Algorithm
by	O
an	O
internal	O
computer	B-General_Concept
bus	I-General_Concept
controller	O
termed	O
the	O
hub	O
.	O
</s>
<s>
Each	O
cog	O
also	O
has	O
access	O
to	O
two	O
dedicated	O
hardware	O
counters	O
and	O
a	O
special	O
video	O
generator	O
for	O
use	O
in	O
generating	O
timing	O
signals	O
for	O
PAL	B-Language
,	O
NTSC	O
,	O
VGA	B-Protocol
,	O
servomechanism-control	O
,	O
and	O
others	O
.	O
</s>
<s>
The	O
Propeller	O
can	O
be	O
clocked	B-Operating_System
using	O
either	O
an	O
internal	O
,	O
on-chip	O
oscillator	O
(	O
providing	O
a	O
lower	O
total	O
part	O
count	O
,	O
but	O
sacrificing	O
some	O
accuracy	O
and	O
thermal	O
stability	O
)	O
or	O
an	O
external	O
crystal	O
oscillator	O
or	O
ceramic	O
resonator	O
(	O
providing	O
higher	O
maximum	O
speed	O
with	O
greater	O
accuracy	O
at	O
higher	O
total	O
cost	O
)	O
.	O
</s>
<s>
When	O
running	O
at	O
80MHz	O
,	O
the	O
proprietary	O
interpreted	O
Spin	O
programming	O
language	O
executes	O
approximately	O
80,000	O
instruction-tokens	O
per	O
second	O
on	O
each	O
core	O
,	O
giving	O
8	O
times	O
80,000	O
for	O
640,000	O
high-level	B-Language
instructions	O
per	O
second	O
.	O
</s>
<s>
Power	O
use	O
can	O
be	O
reduced	O
by	O
lowering	O
the	O
clock	O
rate	O
to	O
what	O
is	O
needed	O
,	O
by	O
turning	O
off	O
unneeded	O
cogs	O
(	O
which	O
then	O
use	O
little	O
power	O
)	O
,	O
and	O
by	O
reconfiguring	O
I/O	O
pins	O
which	O
are	O
unneeded	O
,	O
or	O
can	O
be	O
safely	O
placed	O
in	O
a	O
high-impedance	O
state	O
(	O
tristated	B-Device
)	O
,	O
as	O
inputs	O
.	O
</s>
<s>
Each	O
cog	O
has	O
access	O
to	O
some	O
dedicated	O
counter-timer	O
hardware	O
,	O
and	O
a	O
special	O
timing	O
signal	O
generator	O
intended	O
to	O
simplify	O
the	O
design	O
of	O
video	O
output	O
stages	O
,	O
such	O
as	O
composite	O
PAL	B-Language
or	O
NTSC	O
displays	O
(	O
including	O
modulation	B-Application
for	O
broadcast	O
)	O
and	O
Video	B-Protocol
Graphics	I-Protocol
Array	I-Protocol
(	O
VGA	B-Protocol
)	O
monitors	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
use	O
multiple	O
cogs	O
in	O
parallel	B-Operating_System
to	O
generate	O
a	O
single	O
video	O
signal	O
.	O
</s>
<s>
More	O
generally	O
,	O
the	O
timing	O
hardware	O
can	O
be	O
used	O
to	O
implement	O
various	O
pulse-width	B-Algorithm
modulation	I-Algorithm
(	O
PWM	O
)	O
timing	O
signals	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
Spin	O
interpreter	B-Application
and	O
a	O
boot	B-Application
loader	I-Application
,	O
the	O
built-in	O
ROM	B-Device
provides	O
some	O
data	O
which	O
may	O
be	O
useful	O
for	O
certain	O
sound	O
,	O
video	O
,	O
or	O
mathematics	O
applications	O
:	O
</s>
<s>
The	O
math	O
extensions	O
are	O
intended	O
to	O
help	O
compensate	O
for	O
the	O
lack	O
of	O
a	O
floating-point	B-General_Concept
unit	I-General_Concept
,	O
and	O
more	O
primitive	O
missing	O
operations	O
,	O
such	O
as	O
multiplication	O
and	O
division	O
(	O
this	O
is	O
masked	O
in	O
Spin	O
but	O
is	O
a	O
limit	O
for	O
assembly	B-Language
language	I-Language
routines	O
)	O
.	O
</s>
<s>
Spin	O
is	O
a	O
multitasking	B-Operating_System
high-level	B-Language
computer	O
programming	O
language	O
created	O
by	O
Parallax	O
's	O
Chip	O
Gracey	O
,	O
who	O
also	O
designed	O
the	O
Propeller	B-Architecture
microcontroller	I-Architecture
on	O
which	O
it	O
runs	O
,	O
for	O
their	O
line	O
of	O
Propeller	B-Architecture
microcontrollers	I-Architecture
.	O
</s>
<s>
Spin	O
code	O
is	O
written	O
on	O
the	O
Propeller	O
Tool	O
,	O
a	O
GUI-oriented	O
software	B-Application
development	I-Application
platform	I-Application
written	O
for	O
Windows	O
XP	O
.	O
</s>
<s>
This	O
compiler	O
converts	O
the	O
Spin	O
code	O
into	O
bytecodes	O
that	O
can	O
be	O
loaded	O
(	O
with	O
the	O
same	O
tool	O
)	O
into	O
the	O
main	O
32KB	O
RAM	B-Architecture
,	O
and	O
optionally	O
into	O
the	O
I²C	O
boot	B-Operating_System
electrically	B-General_Concept
erasable	I-General_Concept
programmable	I-General_Concept
read-only	I-General_Concept
memory	I-General_Concept
(	O
EEPROM	B-General_Concept
)	O
,	O
of	O
the	O
Propeller	B-Architecture
chip	I-Architecture
.	O
</s>
<s>
After	O
booting	B-Operating_System
the	O
propeller	O
,	O
a	O
bytecode	O
interpreter	B-Application
is	O
copied	O
from	O
the	O
built	O
in	O
ROM	B-Device
into	O
the	O
2KB	O
RAM	B-Architecture
of	O
the	O
primary	O
COG	O
.	O
</s>
<s>
This	O
COG	O
will	O
then	O
start	O
interpreting	O
the	O
bytecodes	O
in	O
the	O
main	O
32KB	O
RAM	B-Architecture
.	O
</s>
<s>
More	O
than	O
one	O
copy	O
of	O
the	O
bytecode	O
interpreter	B-Application
can	O
run	O
in	O
other	O
COGs	O
,	O
so	O
several	O
Spin	O
code	O
threads	B-Operating_System
can	O
run	O
simultaneously	O
.	O
</s>
<s>
Within	O
a	O
Spin	O
code	O
program	O
,	O
assembly	B-Language
code	I-Language
program(s )	O
can	O
be	O
inline	O
inserted	O
.	O
</s>
<s>
Like	O
Python	B-Language
,	O
Spin	O
uses	O
indentation	O
whitespace	O
,	O
rather	O
than	O
curly	O
braces	O
or	O
keywords	O
,	O
to	O
delimit	O
blocks	O
.	O
</s>
<s>
The	O
Propeller	O
's	O
interpreter	B-Application
for	O
its	O
proprietary	O
multi-threaded	B-Operating_System
Spin	O
computer	O
language	O
is	O
a	O
bytecode	O
interpreter	B-Application
.	O
</s>
<s>
This	O
interpreter	B-Application
decodes	O
strings	O
of	O
instructions	O
,	O
one	O
instruction	O
per	O
byte	B-Application
,	O
from	O
user	O
code	O
which	O
has	O
been	O
edited	O
,	O
compiled	O
,	O
and	O
loaded	O
onto	O
the	O
Propeller	O
from	O
within	O
a	O
purpose-specific	O
integrated	B-Application
development	I-Application
environment	I-Application
(	O
IDE	O
)	O
.	O
</s>
<s>
This	O
IDE	O
,	O
which	O
Parallax	O
names	O
The	O
Propeller	O
tool	O
,	O
is	O
intended	O
for	O
use	O
under	O
a	O
Microsoft	B-Application
Windows	I-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
The	O
Spin	O
language	O
is	O
a	O
high-level	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
Because	O
it	O
is	O
interpreted	O
in	O
software	B-Application
,	O
it	O
runs	O
slower	O
than	O
pure	O
Propeller	O
assembly	O
,	O
but	O
can	O
be	O
more	O
space-efficient	O
:	O
Propeller	O
assembly	O
opcodes	O
are	O
32	O
bits	O
long	O
;	O
Spin	O
directives	O
are	O
8	O
bits	O
long	O
,	O
which	O
may	O
be	O
followed	O
by	O
a	O
number	O
of	O
8-bit	O
bytes	B-Application
to	O
specify	O
how	O
that	O
directive	O
operates	O
.	O
</s>
<s>
Spin	O
also	O
allows	O
avoiding	O
significant	O
memory	B-General_Concept
segmentation	I-General_Concept
issues	O
that	O
must	O
be	O
considered	O
for	O
assembly	B-Language
code	I-Language
.	O
</s>
<s>
At	O
startup	O
,	O
a	O
copy	O
of	O
the	O
bytecode	O
interpreter	B-Application
(	O
less	O
than	O
2KB	O
in	O
size	O
)	O
,	O
will	O
be	O
copied	O
into	O
the	O
dedicated	O
RAM	B-Architecture
of	O
a	O
cog	O
and	O
will	O
then	O
start	O
interpreting	O
bytecode	O
in	O
the	O
main	O
32KB	O
RAM	B-Architecture
.	O
</s>
<s>
Additional	O
cogs	O
can	O
be	O
started	O
from	O
that	O
point	O
,	O
loading	O
a	O
separate	O
copy	O
of	O
the	O
interpreter	B-Application
into	O
the	O
new	O
cog	O
's	O
dedicated	O
RAM	B-Architecture
(	O
a	O
total	O
of	O
eight	O
interpreter	B-Application
threads	B-Operating_System
can	O
,	O
thus	O
,	O
run	O
simultaneously	O
)	O
.	O
</s>
<s>
The	O
Parallax	B-Architecture
Propeller	I-Architecture
is	O
gradually	O
accumulating	O
software	B-Application
libraries	O
which	O
give	O
it	O
similar	O
abilities	O
to	O
Parallax	O
's	O
older	O
BASIC	B-Language
Stamp	I-Language
product	O
;	O
however	O
there	O
is	O
no	O
uniform	O
list	O
of	O
which	O
PBASIC	B-Language
facilities	O
now	O
have	O
Spin	O
equivalents	O
.	O
</s>
<s>
The	O
initial	O
version	O
of	O
the	O
chip	O
(	O
called	O
the	O
P8X32A	O
)	O
provides	O
one	O
32-bit	O
port	O
in	O
a	O
40-pin	O
0.6in	O
dual	B-Algorithm
in-line	I-Algorithm
package	I-Algorithm
(	O
DIP	B-Algorithm
)	O
,	O
44-pin	O
LQFP	O
,	O
or	O
Quad	B-Algorithm
Flat	I-Algorithm
No-leads	I-Algorithm
package	I-Algorithm
(	O
QFN	B-Algorithm
)	O
surface-mount	O
technology	O
package	O
.	O
</s>
<s>
Any	O
of	O
these	O
pins	O
can	O
be	O
used	O
for	O
the	O
timing	O
or	O
pulse-width	B-Algorithm
modulation	I-Algorithm
output	O
techniques	O
described	O
above	O
.	O
</s>
<s>
The	O
Propeller	O
's	O
designers	O
designed	O
it	O
around	O
the	O
concept	O
of	O
"	O
virtual	B-Architecture
I/O	O
devices	O
"	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
HYDRA	O
Game	O
Development	O
Kit	O
,	O
(	O
a	O
computer	O
system	O
designed	O
for	O
hobbyists	O
,	O
to	O
learn	O
to	O
develop	O
retro-style	O
video	O
games	O
)	O
uses	O
the	O
built-in	O
character	O
generator	O
and	O
video	O
support	O
logic	O
to	O
generate	O
a	O
virtual	O
graphics	O
processing	O
unit-generator	O
that	O
outputs	O
VGA	B-Protocol
color	O
pictures	O
,	O
PAL/NTSC	O
compatible	O
color	O
pictures	O
or	O
broadcast	O
RF	O
video+audio	O
in	O
software	B-Application
.	O
</s>
<s>
The	O
screen	O
capture	O
displayed	O
here	O
was	O
made	O
using	O
a	O
software	B-Application
virtual	B-Architecture
display	O
driver	O
that	O
sends	O
the	O
pixel	O
data	O
over	O
a	O
serial	O
link	O
to	O
a	O
PC	O
.	O
</s>
<s>
Software	B-Application
libraries	O
are	O
available	O
to	O
implement	O
several	O
I/O	O
devices	O
ranging	O
from	O
simple	O
UARTs	O
and	O
Serial	O
I/O	O
interfaces	O
such	O
as	O
SPI	O
,	O
I²C	O
and	O
PS/2	O
compatible	O
serial	O
mouse	O
and	O
keyboard	O
interfaces	O
,	O
motor	O
drivers	O
for	O
robotic	O
systems	O
,	O
MIDI	O
interfaces	O
and	O
LCD	O
controllers	O
.	O
</s>
<s>
The	O
design	O
philosophy	O
of	O
the	O
Propeller	O
is	O
that	O
a	O
hard	O
real-time	O
multi-core	B-Architecture
architecture	O
negates	O
the	O
need	O
for	O
dedicated	O
interrupt	B-Application
hardware	O
and	O
support	O
in	O
assembly	O
.	O
</s>
<s>
In	O
traditional	O
CPU	O
architecture	O
,	O
external	O
interrupt	B-Application
lines	I-Application
are	O
fed	O
to	O
an	O
on-chip	O
interrupt	B-Application
controller	O
and	O
are	O
serviced	O
by	O
one	O
or	O
more	O
interrupt	B-General_Concept
service	I-General_Concept
routines	I-General_Concept
.	O
</s>
<s>
When	O
an	O
interrupt	B-Application
occurs	O
,	O
the	O
interrupt	B-Application
controller	O
suspends	O
normal	O
CPU	O
processing	O
and	O
saves	O
internal	O
state	O
(	O
typically	O
on	O
the	O
stack	B-Application
)	O
,	O
then	O
vectors	O
to	O
the	O
designated	O
interrupt	B-General_Concept
service	I-General_Concept
routine	I-General_Concept
.	O
</s>
<s>
After	O
handling	O
the	O
interrupt	B-Application
,	O
the	O
service	O
routine	O
executes	O
a	O
return	O
from	O
interrupt	B-Application
instruction	O
which	O
restores	O
the	O
internal	O
state	O
and	O
resumes	O
CPU	O
processing	O
.	O
</s>
<s>
Extending	O
this	O
technique	O
,	O
a	O
Propeller	O
can	O
be	O
set	O
up	O
to	O
respond	O
to	O
eight	O
independent	O
interrupt	B-Application
lines	I-Application
with	O
essentially	O
zero	O
handling	O
delay	O
.	O
</s>
<s>
Alternately	O
,	O
one	O
line	O
can	O
be	O
used	O
to	O
signal	O
the	O
interrupt	B-Application
,	O
and	O
then	O
additional	O
input	O
lines	O
can	O
be	O
read	O
to	O
determine	O
the	O
nature	O
of	O
the	O
event	O
.	O
</s>
<s>
The	O
code	O
running	O
in	O
the	O
other	O
cores	O
is	O
not	O
affected	O
by	O
the	O
interrupt	B-Application
handling	I-Application
cog	O
.	O
</s>
<s>
Unlike	O
a	O
traditional	O
multitasking	B-Operating_System
single-processor	O
interrupt	B-Application
architecture	O
,	O
the	O
signal	O
response	O
timing	O
remains	O
predictable	B-Application
,	O
and	O
indeed	O
using	O
the	O
term	O
interrupt	B-Application
in	O
this	O
context	O
can	O
cause	O
confusion	O
,	O
since	O
this	O
function	O
can	O
be	O
more	O
properly	O
thought	O
of	O
as	O
polling	O
with	O
a	O
zero	O
loop	O
time	O
.	O
</s>
<s>
On	O
power	O
up	O
,	O
Brownout	O
detection	O
,	O
software	B-Application
reset	O
,	O
or	O
external	O
hardware	O
reset	O
,	O
the	O
Propeller	O
will	O
load	O
a	O
machine-code	O
booting	B-Operating_System
routine	O
from	O
the	O
internal	O
ROM	B-Device
into	O
the	O
RAM	B-Architecture
of	O
its	O
first	O
(	O
primary	O
)	O
cog	O
and	O
execute	O
it	O
.	O
</s>
<s>
This	O
code	O
emulates	B-Application
an	O
I²C	O
interface	O
in	O
software	B-Application
,	O
temporarily	O
using	O
two	O
I/O	O
pins	O
for	O
the	O
needed	O
serial	O
clock	O
and	O
data	O
signals	O
to	O
load	O
user	O
code	O
from	O
an	O
external	O
I2C	O
EEPROM	B-General_Concept
.	O
</s>
<s>
Simultaneously	O
,	O
it	O
emulates	B-Application
a	O
serial	B-Protocol
port	I-Protocol
,	O
using	O
two	O
other	O
I/O	O
pins	O
that	O
can	O
be	O
used	O
to	O
upload	O
software	B-Application
directly	O
to	O
RAM	B-Architecture
(	O
and	O
optionally	O
to	O
the	O
external	O
EEPROM	B-General_Concept
)	O
.	O
</s>
<s>
If	O
the	O
Propeller	O
sees	O
no	O
commands	O
from	O
the	O
serial	B-Protocol
port	I-Protocol
,	O
it	O
loads	O
the	O
user	O
program	O
(	O
the	O
entry	O
code	O
of	O
which	O
must	O
be	O
written	O
in	O
Spin	O
,	O
as	O
described	O
above	O
)	O
from	O
the	O
serial	O
EEPROM	B-General_Concept
into	O
the	O
main	O
32KB	O
RAM	B-Architecture
.	O
</s>
<s>
After	O
that	O
,	O
it	O
loads	O
the	O
Spin	O
interpreter	B-Application
from	O
its	O
built-in	O
ROM	B-Device
into	O
the	O
dedicated	O
RAM	B-Architecture
of	O
its	O
first	O
cog	O
,	O
overwriting	O
most	O
of	O
the	O
bootloader	B-Application
.	O
</s>
<s>
Regardless	O
of	O
how	O
the	O
user	O
program	O
is	O
loaded	O
,	O
execution	O
starts	O
by	O
interpreting	O
initial	O
user	O
bytecode	O
with	O
the	O
Spin	O
interpreter	B-Application
running	O
in	O
the	O
primary	O
cog	O
.	O
</s>
<s>
After	O
this	O
initial	O
Spin	O
code	O
runs	O
,	O
the	O
application	O
can	O
turn	O
on	O
any	O
unused	O
cog	O
to	O
start	O
a	O
new	O
thread	B-Operating_System
,	O
and/or	O
start	O
assembly	B-Language
language	I-Language
routines	O
.	O
</s>
<s>
The	O
Propeller	O
boots	O
from	O
an	O
external	O
serial	O
EEPROM	B-General_Concept
;	O
once	O
the	O
boot	B-Operating_System
sequence	I-Operating_System
completes	O
,	O
this	O
device	O
may	O
be	O
accessed	O
as	O
an	O
external	O
peripheral	O
.	O
</s>
<s>
Apart	O
from	O
Spin	O
and	O
the	O
Propeller	O
's	O
low-level	O
assembler	B-Language
,	O
a	O
number	O
of	O
other	O
languages	O
have	O
been	O
ported	O
to	O
it	O
.	O
</s>
<s>
Parallax	O
supports	O
Propeller-GCC	O
which	O
is	O
a	O
port	O
of	O
the	O
GNU	B-Application
Compiler	I-Application
Collection	I-Application
(	O
GCC	B-Application
)	O
compiler	O
for	O
the	O
programming	O
languages	O
C	B-Language
and	O
C++	B-Language
,	O
for	O
Propeller	O
(	O
branch	O
release_1_0	O
)	O
.	O
</s>
<s>
The	O
C	B-Language
compiler	O
and	O
the	O
C	B-Language
Library	O
are	O
ANSI	O
C	B-Language
compliant	O
.	O
</s>
<s>
The	O
C++	B-Language
compiler	O
is	O
ANSI-C99	O
compliant	O
.	O
</s>
<s>
Full	O
C++	B-Language
is	O
supported	O
with	O
external	O
memory	O
.	O
</s>
<s>
The	O
SimpleIDE	O
program	O
provides	O
users	O
a	O
simple	O
way	O
to	O
write	O
programs	O
without	O
requiring	O
makefiles	B-Application
.	O
</s>
<s>
In	O
2013	O
,	O
Parallax	O
incorporated	O
Propeller-GCC	O
and	O
Simple	O
Libraries	O
into	O
the	O
Propeller-C	O
Learn	O
series	O
of	O
tutorials	O
.	O
</s>
<s>
Propeller-GCC	O
is	O
actively	O
maintained	O
.	O
</s>
<s>
Propeller-GCC	O
and	O
SimpleIDE	O
are	O
officially	O
supported	O
Parallax	O
software	B-Application
products	O
.	O
</s>
<s>
The	O
ImageCraft	O
ICCV7	O
for	O
Propeller	O
C	B-Language
compiler	O
has	O
been	O
marked	O
to	O
end-of-life	O
state	O
.	O
</s>
<s>
A	O
free	O
ANSI	O
C	B-Language
compiler	O
named	O
Catalina	O
is	O
available	O
.	O
</s>
<s>
It	O
is	O
based	O
on	O
LCC	B-Language
.	O
</s>
<s>
PropBASIC	O
is	O
a	O
BASIC	O
programming	O
language	O
for	O
the	O
Parallax	B-Architecture
Propeller	I-Architecture
Microcontroller	B-Architecture
.	O
</s>
<s>
PropBASIC	O
requires	O
Brad	O
's	O
Spin	O
Tool	O
(	O
BST	O
)	O
,	O
a	O
cross-platform	B-Operating_System
set	O
of	O
tools	O
for	O
developing	O
with	O
the	O
Parallax	B-Architecture
Propeller	I-Architecture
.	O
</s>
<s>
As	O
of	O
August	O
2015	O
,	O
BST	O
runs	O
on	O
i386-linux-gtk2	O
,	O
PowerPC-darwin	O
(	O
Mac	B-Application
OS	I-Application
X	I-Application
10.4	O
through	O
10.6	O
)	O
,	O
i386-darwin	O
(	O
Mac	B-Application
OS	I-Application
X	I-Application
10.4	O
through	O
10.6	O
)	O
and	O
i386-Win32	O
(	O
Windows	B-Application
95	I-Application
through	O
Windows	B-Device
7	I-Device
)	O
.	O
</s>
<s>
There	O
are	O
at	O
least	O
six	O
different	O
versions	O
of	O
Forth	B-Application
,	O
both	O
commercial	B-Application
and	O
open-source	B-Application
software	I-Application
,	O
available	O
for	O
the	O
Propeller	O
.	O
</s>
<s>
It	O
is	O
tailored	O
to	O
the	O
prop	O
architecture	O
,	O
and	O
necessarily	O
deviates	O
from	O
any	O
general	O
standard	O
regarding	O
architectural	O
uniqueness	O
,	O
consistent	O
with	O
the	O
concept	O
of	O
Forth	B-Application
.	O
</s>
<s>
Beyond	O
the	O
Forth	B-Application
interpreter	B-Application
,	O
PropForth	O
provides	O
many	O
features	O
that	O
exploit	O
the	O
chip	O
's	O
abilities	O
.	O
</s>
<s>
LogicAnalyzer	O
refers	O
to	O
an	O
extension	O
package	O
that	O
implements	O
software	B-Application
logic	O
analyzer	O
.	O
</s>
<s>
EEPROMfilesystem	O
and	O
SDfilesystem	O
are	O
extensions	O
that	O
implement	O
rudimentary	O
storage	O
using	O
EEPROM	B-General_Concept
and	O
SD	O
flash	O
.	O
</s>
<s>
PagedAssembler	O
refers	O
to	O
the	O
package	O
of	O
optimizations	O
that	O
allow	O
assembler	B-Language
routines	O
to	O
be	O
swapped	O
in	O
(	O
and	O
out	O
by	O
overwrite	O
)	O
on	O
the	O
fly	O
,	O
allowing	O
virtually	O
unlimited	O
application	O
size	O
.	O
</s>
<s>
There	O
are	O
efforts	O
underway	O
to	O
run	O
the	O
Java	B-Language
virtual	I-Language
machine	I-Language
(	O
JVM	B-Language
)	O
on	O
Propeller	O
.	O
</s>
<s>
A	O
compiler	O
,	O
debugger	O
,	O
and	O
emulator	B-Application
are	O
being	O
developed	O
.	O
</s>
<s>
A	O
large	O
subset	O
of	O
Pascal	B-Application
is	O
implemented	O
by	O
a	O
compiler	O
and	O
interpreter	B-Application
based	O
on	O
the	O
p-code	B-Language
machine	I-Language
P4	O
system	O
.	O
</s>
<s>
PICo	O
programmable	B-Architecture
logic	I-Architecture
controller	I-Architecture
(	O
PLC	O
,	O
PICoPLC	O
)	O
supports	O
output	O
to	O
Propeller	O
processor	O
.	O
</s>
<s>
PICoPLC	O
also	O
supports	O
P8X32	B-Architecture
with	O
create-simulate-run	O
feature	O
.	O
</s>
