<s>
The	O
Nintendo	B-Operating_System
64	I-Operating_System
's	O
programming	O
characteristics	O
describe	O
the	O
elements	O
of	O
writing	O
software	O
for	O
the	O
Nintendo	B-Operating_System
64	I-Operating_System
(	O
N64	B-Operating_System
)	O
gaming	O
system	O
.	O
</s>
<s>
The	O
Nintendo	B-Operating_System
64	I-Operating_System
was	O
released	O
in	O
1996	O
.	O
</s>
<s>
As	O
the	O
Nintendo	B-Operating_System
64	I-Operating_System
reached	O
the	O
end	O
of	O
its	O
lifecycle	O
,	O
hardware	O
development	O
chief	O
Genyo	O
Takeda	O
referred	O
to	O
its	O
programming	O
challenges	O
using	O
the	O
word	O
hansei	O
(	O
"	O
reflective	O
regret	O
"	O
)	O
.	O
</s>
<s>
Takeda	O
said	O
,	O
"	O
When	O
we	O
made	O
Nintendo	B-Operating_System
64	I-Operating_System
,	O
we	O
thought	O
it	O
was	O
logical	O
that	O
if	O
you	O
want	O
to	O
make	O
advanced	O
games	O
,	O
it	O
becomes	O
technically	O
more	O
difficult	O
.	O
</s>
<s>
The	O
console	O
uses	O
high-bandwidth	O
but	O
high-latency	B-Architecture
Rambus	O
DRAM	O
.	O
</s>
<s>
There	O
is	O
a	O
physical	O
address	O
space	O
into	O
which	O
the	O
majority	O
of	O
resources	O
are	O
mapped	O
,	O
including	O
the	O
Game	O
Pak	O
,	O
the	O
RSP	O
instruction	O
and	O
data	O
local	B-Device
storage	I-Device
,	O
but	O
neither	O
the	O
RDP	O
texture	O
local	B-Device
storage	I-Device
nor	O
any	O
CPU	O
cache	O
.	O
</s>
<s>
The	O
RSP	O
can	O
address	O
only	O
its	O
local	B-Device
storage	I-Device
,	O
and	O
can	O
program	O
its	O
DMA	O
engine	O
.	O
</s>
<s>
The	O
RDP	O
DMA	O
engine	O
handles	O
command	O
buffers	O
(	O
so-called	O
display	O
lists	O
)	O
;	O
the	O
RDP	O
has	O
a	O
further	O
memory	O
front	O
end	O
for	O
accessing	O
video	O
buffers	O
and	O
data	O
,	O
able	O
to	O
directly	O
fetch	O
from	O
the	O
RSP	O
data	O
local	B-Device
storage	I-Device
through	O
a	O
separate	O
data	O
path	O
.	O
</s>
<s>
The	O
R4300	B-Device
CPU	O
is	O
connected	O
to	O
the	O
RCP	O
through	O
the	O
microprocessor	O
interface	O
,	O
and	O
can	O
perform	O
programmed	O
IO	O
through	O
its	O
cache	O
and	O
memory	O
frontend	O
.	O
</s>
<s>
When	O
mipmapping	B-Data_Structure
is	O
used	O
,	O
texture	O
width	O
requirements	O
and	O
the	O
extra	O
storage	O
for	O
the	O
mipmap	B-Data_Structure
levels	O
limit	O
the	O
largest	O
mipmap	B-Data_Structure
level	O
to	O
2KB	O
.	O
</s>
<s>
Toward	O
the	O
end	O
of	O
the	O
Nintendo	B-Operating_System
64	I-Operating_System
's	O
market	O
cycle	O
,	O
some	O
developers	O
precomputed	O
their	O
textures	O
using	O
multi-layered	O
texturing	O
and	O
small	O
texture	O
pieces	O
that	O
were	O
heavily	O
clamped	O
,	O
to	O
simulate	O
larger	O
textures	O
.	O
</s>
<s>
Examples	O
of	O
this	O
workaround	O
are	O
found	O
in	O
Rare	O
's	O
Perfect	B-Application
Dark	I-Application
,	O
Banjo-Tooie	B-Application
,	O
Conker	B-Application
's	I-Application
Bad	I-Application
Fur	I-Application
Day	I-Application
,	O
and	O
in	O
Factor	O
5	O
's	O
Indiana	B-Application
Jones	I-Application
and	I-Application
the	I-Application
Infernal	I-Application
Machine	I-Application
.	O
</s>
<s>
Some	O
games	O
with	O
non-realistic	O
aesthetics	O
use	O
plain	O
colored	O
Gouraud	B-Algorithm
shading	I-Algorithm
instead	O
of	O
texturing	O
on	O
certain	O
surfaces	O
(	O
e.g.	O
,	O
Super	B-Application
Mario	I-Application
64	I-Application
)	O
.	O
</s>
<s>
Many	O
Nintendo	B-Operating_System
64	I-Operating_System
games	O
are	O
fill-rate	O
limited	O
,	O
not	O
geometry	O
limited	O
.	O
</s>
<s>
Optimization	O
is	O
possible	O
by	O
pushing	O
this	O
function	O
onto	O
the	O
RSP	O
and	O
CPU	O
using	O
a	O
custom	O
microcode	B-Device
.	O
</s>
<s>
Significant	O
performance	O
Optimization	O
can	O
be	O
found	O
by	O
using	O
a	O
microcode	B-Device
appropriate	O
for	O
each	O
game	O
.	O
</s>
<s>
The	O
Nintendo	B-Operating_System
64	I-Operating_System
's	O
polygon	O
per	O
second	O
rating	O
is	O
about	O
160,000	O
with	O
hardware	O
features	O
enabled	O
.	O
</s>
<s>
Some	O
of	O
the	O
more	O
polygon-intense	O
Nintendo	B-Operating_System
64	I-Operating_System
games	O
include	O
World	B-Device
Driver	I-Device
Championship	I-Device
,	O
Turok	B-Application
2	I-Application
:	I-Application
Seeds	I-Application
of	I-Application
Evil	I-Application
,	O
and	O
Indiana	B-Application
Jones	I-Application
and	I-Application
the	I-Application
Infernal	I-Application
Machine	I-Application
.	O
</s>
<s>
The	O
Reality	O
Signal	O
Processor	O
(	O
RSP	O
)	O
accepts	O
microcode	B-Device
,	O
through	O
which	O
,	O
a	O
developer	O
can	O
access	O
different	O
operations	O
,	O
create	O
new	O
effects	O
,	O
and	O
optimize	O
for	O
speed	O
or	O
quality	O
.	O
</s>
<s>
The	O
efficacious	O
use	O
of	O
this	O
engine	O
is	O
governed	O
by	O
the	O
microcode	B-Device
,	O
which	O
defines	O
a	O
small	O
instruction	O
sequence	O
for	O
each	O
complex	O
instruction	O
.	O
</s>
<s>
While	O
promoting	O
the	O
feature	O
of	O
custom	O
microcodes	B-Device
,	O
Nintendo	O
initially	O
refused	O
to	O
share	O
information	O
on	O
how	O
to	O
use	O
the	O
related	O
microcode	B-Device
tools	O
.	O
</s>
<s>
However	O
during	O
the	O
console	O
's	O
last	O
few	O
years	O
,	O
Nintendo	O
shared	O
the	O
microcode	B-Device
information	O
with	O
a	O
few	O
developers	O
.	O
</s>
<s>
SGI	O
's	O
default	O
microcode	B-Device
for	O
Nintendo	B-Operating_System
64	I-Operating_System
is	O
called	O
"	O
Fast3D	O
"	O
,	O
which	O
some	O
developers	O
claimed	O
was	O
poorly	O
profiled	O
for	O
use	O
in	O
games	O
.	O
</s>
<s>
Although	O
it	O
generates	O
more	O
than	O
100,000	O
high	O
accuracy	O
polygons	O
per	O
second	O
,	O
this	O
microcode	B-Device
is	O
optimized	O
more	O
for	O
accuracy	O
than	O
for	O
speed	O
,	O
and	O
performance	O
suffered	O
.	O
</s>
<s>
Nintendo	O
's	O
"	O
Turbo3D	O
"	O
microcode	B-Device
allows	O
500,000	O
–	O
600,000	O
normal	O
accuracy	O
polygons	O
per	O
second	O
.	O
</s>
<s>
Companies	O
such	O
as	O
Factor	O
5	O
,	O
Boss	O
Game	O
Studios	O
,	O
and	O
Rare	O
were	O
able	O
to	O
write	O
custom	O
microcode	B-Device
that	O
reportedly	O
runs	O
their	O
game	O
engines	O
better	O
than	O
SGI	O
's	O
standard	O
microcode	B-Device
.	O
</s>
<s>
One	O
of	O
the	O
best	O
examples	O
of	O
custom	O
microcode	B-Device
is	O
Factor	O
5	O
's	O
N64	B-Operating_System
port	O
of	O
the	O
Indiana	B-Application
Jones	I-Application
and	I-Application
the	I-Application
Infernal	I-Application
Machine	I-Application
PC	O
game	O
.	O
</s>
<s>
They	O
took	O
advantage	O
of	O
the	O
cartridge	O
as	O
a	O
texture	O
streaming	B-Architecture
source	O
to	O
squeeze	O
as	O
much	O
detail	O
as	O
possible	O
into	O
each	O
environment	O
and	O
work	O
around	O
RAM	O
limitations	O
.	O
</s>
<s>
They	O
wrote	O
microcode	B-Device
for	O
real-time	O
lighting	O
,	O
because	O
the	O
supplied	O
microcode	B-Device
from	O
SGI	O
was	O
not	O
optimized	O
for	O
this	O
task	O
,	O
and	O
because	O
they	O
wanted	O
to	O
have	O
more	O
lighting	O
than	O
the	O
PC	O
version	O
.	O
</s>
<s>
Factor	O
5	O
's	O
microcode	B-Device
allows	O
almost	O
unlimited	O
realtime	O
lighting	O
and	O
significantly	O
boosts	O
the	O
polygon	O
count	O
.	O
</s>
<s>
In	O
the	O
end	O
,	O
the	O
N64	B-Operating_System
version	O
is	O
said	O
to	O
be	O
more	O
feature-rich	O
than	O
the	O
PC	O
version	O
,	O
and	O
is	O
considered	O
to	O
be	O
one	O
of	O
the	O
unit	O
's	O
most	O
advanced	O
games	O
.	O
</s>
<s>
Factor	O
5	O
again	O
used	O
custom	O
microcode	B-Device
with	O
games	O
such	O
as	O
Star	B-Application
Wars	I-Application
:	I-Application
Rogue	I-Application
Squadron	I-Application
and	O
Star	B-Application
Wars	I-Application
:	I-Application
Episode	I-Application
I	I-Application
:	I-Application
Battle	I-Application
for	I-Application
Naboo	I-Application
.	O
</s>
<s>
In	O
Star	B-Application
Wars	I-Application
:	I-Application
Rogue	I-Application
Squadron	I-Application
,	O
the	O
team	O
tweaked	O
the	O
microcode	B-Device
for	O
a	O
landscape	O
engine	O
to	O
create	O
the	O
alien	O
worlds	O
.	O
</s>
<s>
For	O
Star	B-Application
Wars	I-Application
:	I-Application
Battle	I-Application
for	I-Application
Naboo	I-Application
,	O
they	O
used	O
what	O
they	O
learned	O
from	O
Rogue	O
Squadron	O
and	O
made	O
the	O
game	O
run	O
at	O
640×480	O
,	O
also	O
implementing	O
enhancements	O
for	O
particles	O
and	O
the	O
landscape	O
engine	O
.	O
</s>
<s>
Battle	B-Application
for	I-Application
Naboo	I-Application
has	O
a	O
long	O
draw	B-General_Concept
distance	I-General_Concept
and	O
large	O
amounts	O
of	O
snow	O
and	O
rain	O
,	O
even	O
in	O
high	O
resolution	O
mode	O
.	O
</s>
<s>
In	O
reality	O
,	O
N64	B-Operating_System
games	O
with	O
high	O
resolution	O
(	O
480i	O
)	O
modes	O
rarely	O
ran	O
at	O
640x480	O
,	O
in	O
Factor	O
5	O
games	O
case	O
,	O
the	O
high	O
resolution	O
was	O
instead	O
set	O
to	O
400x440	O
,	O
Turok	B-Application
2	I-Application
,	O
Turok	O
3	O
and	O
Turok	O
Rage	O
Wars	O
used	O
480x360	O
while	O
Perfect	B-Application
Dark	I-Application
used	O
640x222	O
in	O
NTSC	O
,	O
448x268	O
in	O
PAL	O
.	O
</s>
