<s>
The	O
Macintosh	B-Device
Quadra	I-Device
is	O
a	O
family	O
of	O
personal	B-Device
computers	I-Device
designed	O
,	O
manufactured	O
and	O
sold	O
by	O
Apple	O
Computer	O
,	O
Inc	O
.	O
from	O
October	O
1991	O
to	O
October	O
1995	O
.	O
</s>
<s>
The	O
Quadra	O
,	O
named	O
for	O
the	O
Motorola	B-Device
68040	I-Device
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
,	O
replaced	O
the	O
Macintosh	B-Device
II	I-Device
family	I-Device
as	O
the	O
high-end	O
Macintosh	B-Device
model	O
.	O
</s>
<s>
The	O
first	O
models	O
were	O
the	O
Quadra	B-Device
700	I-Device
and	O
Quadra	B-Device
900	I-Device
,	O
both	O
introduced	O
in	O
October	O
1991	O
.	O
</s>
<s>
The	O
Quadra	B-Device
800	I-Device
,	O
840AV	B-Device
and	O
605	B-Device
were	O
added	O
through	O
1993	O
.	O
</s>
<s>
The	O
Macintosh	B-Device
Centris	I-Device
line	O
was	O
merged	O
with	O
the	O
Quadra	O
in	O
October	O
1993	O
,	O
adding	O
the	O
610	B-Device
,	O
650	B-Device
and	O
660AV	B-Device
to	O
the	O
range	O
.	O
</s>
<s>
After	O
the	O
introduction	O
of	O
the	O
Power	B-Device
Macintosh	I-Device
line	O
in	O
early	O
1994	O
,	O
Apple	O
continued	O
to	O
produce	O
and	O
sell	O
new	O
Quadra	O
models	O
;	O
the	O
950	B-Device
continued	O
to	O
be	O
sold	O
until	O
October	O
,	O
1995	O
.	O
</s>
<s>
The	O
product	O
manager	O
for	O
the	O
Quadra	O
family	O
was	O
Frank	O
Casanova	O
who	O
was	O
also	O
the	O
Product	O
Manager	O
for	O
the	O
Macintosh	B-Device
IIfx	I-Device
.	O
</s>
<s>
The	O
first	O
computers	O
bearing	O
the	O
Macintosh	B-Device
Quadra	I-Device
name	O
were	O
the	O
Quadra	B-Device
700	I-Device
and	O
Quadra	B-Device
900	I-Device
,	O
both	O
introduced	O
in	O
1991	O
with	O
a	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
CPU	O
)	O
speed	O
of	O
25	O
MHz	O
.	O
</s>
<s>
The	O
700	O
was	O
a	O
compact	O
model	O
using	O
the	O
same	O
case	O
dimensions	O
as	O
the	O
Macintosh	B-Device
IIci	I-Device
,	O
with	O
a	O
Processor	B-Device
Direct	I-Device
Slot	I-Device
(	O
PDS	O
)	O
expansion	O
slot	O
,	O
while	O
the	O
latter	O
was	O
a	O
newly	O
designed	O
tower	B-General_Concept
case	I-General_Concept
with	O
five	O
NuBus	B-Device
expansion	O
slots	O
and	O
one	O
PDS	B-Device
slot	I-Device
.	O
</s>
<s>
The	O
900	O
was	O
replaced	O
in	O
1992	O
with	O
the	O
Quadra	B-Device
950	I-Device
,	O
with	O
a	O
CPU	O
speed	O
of	O
33MHz	O
.	O
</s>
<s>
The	O
line	O
was	O
joined	O
by	O
a	O
number	O
of	O
"	O
800-series	O
"	O
machines	O
in	O
a	O
new	O
minitower	B-General_Concept
case	O
design	O
,	O
starting	O
with	O
the	O
Quadra	B-Device
800	I-Device
,	O
and	O
the	O
"	O
600-series	O
"	O
pizza	B-General_Concept
box	I-General_Concept
desktop	B-General_Concept
cases	I-General_Concept
with	O
the	O
Quadra	B-Device
610	I-Device
.	O
</s>
<s>
In	O
1993	O
,	O
the	O
Quadra	B-Device
840AV	I-Device
and	O
660AV	B-Device
were	O
introduced	O
at	O
40MHz	O
and	O
25MHz	O
respectively	O
.	O
</s>
<s>
They	O
included	O
an	O
AT&T	O
3210	O
Digital	B-Architecture
signal	I-Architecture
processor	I-Architecture
and	O
S-Video	O
and	O
composite	O
video	O
input/output	O
ports	O
,	O
as	O
well	O
as	O
CD-quality	O
microphone	B-Application
and	O
audio	O
output	O
ports	O
.	O
</s>
<s>
The	O
AV	O
models	O
also	O
introduced	O
PlainTalk	B-Operating_System
,	O
consisting	O
of	O
the	O
text-to-speech	O
software	O
MacinTalk	B-Operating_System
Pro	O
and	O
speech	O
control	O
(	O
although	O
not	O
dictation	O
)	O
.	O
</s>
<s>
However	O
all	O
of	O
these	O
features	O
were	O
poorly	O
supported	O
in	O
software	O
and	O
a	O
DSP	O
was	O
not	O
installed	O
in	O
later	O
AV	O
Macs	B-Device
,	O
which	O
were	O
based	O
on	O
the	O
more	O
powerful	O
PowerPC	O
601	O
-	O
a	O
CPU	O
powerful	O
enough	O
to	O
handle	O
the	O
coprocessor	O
's	O
duties	O
on	O
its	O
own	O
.	O
</s>
<s>
The	O
Quadra	O
name	O
was	O
also	O
used	O
for	O
the	O
successors	O
to	O
the	O
Centris	B-Device
models	O
that	O
briefly	O
existed	O
during	O
1993	O
:	O
The	O
610	B-Device
,	O
the	O
650	B-Device
and	O
the	O
660AV	B-Device
.	O
</s>
<s>
Centris	B-Device
was	O
a	O
"	O
mid-range	O
"	O
line	O
of	O
systems	O
between	O
the	O
Quadra	O
on	O
the	O
high	O
end	O
and	O
the	O
LC	B-Device
on	O
the	O
low	O
end	O
,	O
but	O
it	O
was	O
later	O
decided	O
that	O
there	O
were	O
too	O
many	O
product	O
lines	O
and	O
the	O
name	O
was	O
dropped	O
.	O
</s>
<s>
Some	O
machines	O
of	O
this	O
era	O
including	O
the	O
Quadra	B-Device
605	I-Device
were	O
also	O
sold	O
as	O
Performas	B-Device
.	O
</s>
<s>
The	O
last	O
use	O
of	O
the	O
name	O
was	O
for	O
the	O
Quadra	B-Device
630	I-Device
,	O
which	O
was	O
a	O
variation	O
of	O
the	O
LC	B-Device
630	O
using	O
a	O
"	O
full	O
"	O
Motorola	B-Device
68040	I-Device
instead	O
of	O
the	O
LC	B-Device
's	O
68LC040	O
,	O
and	O
introduced	O
together	O
with	O
it	O
in	O
1994	O
.	O
</s>
<s>
The	O
630	O
was	O
the	O
first	O
Mac	B-Device
to	O
use	O
an	O
IDE	B-Protocol
based	O
drive	O
bus	O
for	O
the	O
internal	O
hard	B-Device
disk	I-Device
drive	I-Device
,	O
whereas	O
all	O
earlier	O
models	O
had	O
used	O
SCSI	B-Architecture
.	O
</s>
<s>
The	O
first	O
three	O
Apple	B-Device
Workgroup	I-Device
Server	I-Device
models	O
,	O
the	O
WGS	O
60	O
,	O
the	O
WGS	O
80	O
and	O
the	O
WGS	O
95	O
(	O
mostly	O
called	O
"	O
AWS	O
95	O
"	O
for	O
"	O
Apple	B-Device
Workgroup	I-Device
Server	I-Device
"	O
)	O
were	O
based	O
on	O
the	O
Centris	B-Device
610	I-Device
,	O
the	O
Quadra	B-Device
800	I-Device
and	O
the	O
Quadra	B-Device
950	I-Device
,	O
respectively	O
.	O
</s>
<s>
The	O
transition	O
to	O
the	O
Motorola	B-Device
68040	I-Device
was	O
not	O
as	O
smooth	O
as	O
the	O
previous	O
transitions	O
to	O
the	O
Motorola	B-Device
68020	I-Device
or	O
Motorola	B-Device
68030	I-Device
.	O
</s>
<s>
Due	O
to	O
the	O
Motorola	B-Device
68040	I-Device
's	O
split	O
instruction	O
and	O
data	O
caches	O
,	O
the	O
Quadra	O
had	O
compatibility	O
problems	O
with	O
self-modifying	B-Application
code	I-Application
(	O
including	O
relocating	O
code	O
,	O
which	O
was	O
common	O
under	O
the	O
Macintosh	B-General_Concept
memory	I-General_Concept
model	I-General_Concept
)	O
.	O
</s>
<s>
Apple	O
partially	O
fixed	O
this	O
by	O
having	O
the	O
basic	O
Mac	B-Device
OS	O
memory	B-Architecture
copy	O
call	O
flush	O
the	O
caches	O
.	O
</s>
<s>
This	O
solved	O
the	O
vast	O
majority	O
of	O
stability	O
problems	O
,	O
but	O
negated	O
much	O
of	O
the	O
Motorola	B-Device
68040	I-Device
's	O
performance	O
improvements	O
.	O
</s>
<s>
Apple	O
also	O
introduced	O
a	O
variant	O
of	O
the	O
memory	B-Architecture
copy	O
call	O
that	O
did	O
not	O
flush	O
the	O
cache	O
.	O
</s>
<s>
The	O
new	O
trap	O
was	O
defined	O
in	O
such	O
a	O
way	O
that	O
calling	O
it	O
on	O
an	O
older	O
version	O
of	O
Mac	B-Device
OS	O
would	O
simply	O
call	O
the	O
previous	O
memory	B-Architecture
copy	O
routine	O
.	O
</s>
<s>
The	O
net	O
effect	O
of	O
this	O
was	O
that	O
many	O
complex	O
applications	O
were	O
initially	O
slow	O
or	O
prone	O
to	O
crashing	O
on	O
the	O
68040	B-Device
,	O
although	O
developers	O
quickly	O
adapted	O
to	O
the	O
new	O
architecture	O
by	O
relying	O
on	O
Apple	O
's	O
memory	B-Architecture
copy	O
routines	O
rather	O
than	O
their	O
own	O
(	O
or	O
flushing	O
the	O
cache	O
)	O
,	O
and	O
using	O
the	O
memory	B-Architecture
copy	O
that	O
did	O
not	O
flush	O
the	O
cache	O
when	O
appropriate	O
(	O
most	O
of	O
the	O
time	O
)	O
.	O
</s>
<s>
|	O
Power	B-Device
Macintosh	I-Device
6300	O
Model	O
Marketing	O
model	O
no	O
.	O
</s>
