<s>
The	O
Power	B-Device
Macintosh	I-Device
6400	I-Device
(	O
also	O
sold	O
under	O
variations	O
of	O
the	O
name	O
Performa	B-Device
6400	I-Device
)	O
is	O
a	O
personal	B-Device
computer	I-Device
designed	O
,	O
manufactured	O
and	O
sold	O
by	O
Apple	O
Computer	O
from	O
August	O
1996	O
to	O
August	O
1997	O
.	O
</s>
<s>
It	O
is	O
the	O
only	O
Macintosh	B-Device
mini-tower	O
system	O
to	O
be	O
branded	O
as	O
a	O
Performa	B-Device
,	O
and	O
alongside	O
the	O
Performa	B-Device
6360	O
was	O
the	O
last	O
new	O
Performa-branded	O
model	O
introduced	O
by	O
Apple	O
.	O
</s>
<s>
The	O
6400	O
and	O
its	O
Performa	B-Device
variants	O
were	O
discontinued	O
in	O
favor	O
of	O
the	O
uniformly-named	O
Power	B-Device
Macintosh	I-Device
6500	I-Device
in	O
August	O
1997	O
.	O
</s>
<s>
Logic	O
board	O
:	O
The	O
logic	O
board	O
,	O
code-named	O
"	O
Alchemy	O
"	O
,	O
is	O
shared	O
with	O
the	O
Power	B-Device
Macintosh	I-Device
5400	I-Device
all-in-one	O
and	O
Performa	B-Device
6360	O
desktop	O
models	O
.	O
</s>
<s>
Sound	O
:	O
The	O
new	O
"	O
InstaTower	O
"	O
case	O
features	O
an	O
integrated	O
subwoofer	B-Application
speaker	O
and	O
supports	O
SRS	O
surround-sound	O
.	O
</s>
<s>
A	O
knob	O
on	O
the	O
back	O
of	O
the	O
case	O
controls	O
the	O
bass	O
level	O
of	O
the	O
subwoofer	B-Application
;	O
this	O
knob	O
only	O
works	O
if	O
external	O
speakers	O
are	O
connected	O
,	O
otherwise	O
the	O
internal	O
speaker	O
provides	O
full	O
sound	O
range	O
.	O
</s>
<s>
The	O
communication	O
slot	O
is	O
not	O
compatible	O
with	O
similar	O
slots	O
on	O
other	O
Macintosh	B-Device
computers	O
.	O
</s>
<s>
NuBus	B-Device
cards	O
are	O
not	O
supported	O
.	O
</s>
<s>
Operating	O
system	O
:	O
The	O
Performa	O
6400/180	O
and	O
6400/200	O
were	O
shipped	O
with	O
System	B-Operating_System
7.5.3	I-Operating_System
Revision	O
2.1	O
;	O
this	O
particular	O
release	O
was	O
specific	O
to	O
these	O
machines	O
as	O
there	O
were	O
stability	O
problems	O
with	O
System	B-Operating_System
7.5.3	I-Operating_System
Release	O
2	O
on	O
the	O
new	O
hardware	O
,	O
especially	O
with	O
the	O
video	O
card	O
and	O
transferring	O
files	O
over	O
LocalTalk	O
.	O
</s>
<s>
All	O
Performa	B-Device
models	O
shipped	O
with	O
SurfWatch	B-Protocol
,	O
a	O
product	O
from	O
Spyglass	B-Application
,	I-Application
Inc	I-Application
.	I-Application
that	O
provides	O
adult	O
content	B-Protocol
filtering	I-Protocol
capability	O
;	O
content-control	B-Protocol
software	I-Protocol
was	O
a	O
significant	O
issue	O
at	O
the	O
time	O
due	O
to	O
the	O
recent	O
passage	O
of	O
the	O
Communications	O
Decency	O
Act	O
in	O
the	O
United	O
States	O
.	O
</s>
<s>
Performa	B-Device
6410	I-Device
:	O
Identical	O
to	O
the	O
Performa	O
6400/180	O
,	O
sold	O
in	O
Europe	O
and	O
Asia	O
.	O
</s>
<s>
Performa	B-Device
6420	I-Device
:	O
Identical	O
to	O
the	O
Performa	O
6400/200	O
,	O
sold	O
in	O
Europe	O
and	O
Asia	O
.	O
</s>
