<s>
The	O
Macintosh	B-Device
Quadra	I-Device
840AV	I-Device
is	O
a	O
personal	B-Device
computer	I-Device
designed	O
,	O
manufactured	O
,	O
and	O
sold	O
by	O
Apple	O
Computer	O
from	O
July	O
1993	O
to	O
July	O
1994	O
.	O
</s>
<s>
It	O
was	O
introduced	O
alongside	O
the	O
Centris	B-Device
660AV	I-Device
,	O
where	O
"	O
AV	O
"	O
signifies	O
audiovisual	O
capabilities	O
,	O
such	O
as	O
video	O
input	O
and	O
output	O
,	O
telecommunications	O
,	O
speech	O
recognition	O
,	O
and	O
enhanced	O
audio	O
.	O
</s>
<s>
The	O
840AV	O
has	O
the	O
same	O
mini-tower	O
form	O
factor	O
as	O
the	O
Quadra	B-Device
800	I-Device
,	O
with	O
a	O
faster	O
Motorola	B-Device
68040	I-Device
processor	O
.	O
</s>
<s>
The	O
Quadra	B-Device
840AV	I-Device
was	O
discontinued	O
shortly	O
after	O
the	O
introduction	O
of	O
the	O
PowerPC-based	O
Power	B-Device
Macintosh	I-Device
.	O
</s>
<s>
The	O
Power	B-Device
Macintosh	I-Device
8100/80AV	I-Device
provides	O
the	O
same	O
functionality	O
in	O
the	O
same	O
form	O
factor	O
,	O
and	O
had	O
a	O
significantly	O
higher	O
price	O
point	O
.	O
</s>
<s>
The	O
7100/66AV	B-Device
was	O
priced	O
comparably	O
to	O
the	O
840AV	O
but	O
in	O
a	O
IIvx-style	O
desktop	O
case	O
.	O
</s>
<s>
At	O
launch	O
,	O
Quadra	B-Device
840AV	I-Device
's	O
40MHz	O
Motorola	B-Device
68040	I-Device
CPU	O
and	O
interleaved	B-General_Concept
RAM	I-General_Concept
made	O
it	O
the	O
fastest	O
Macintosh	O
available	O
,	O
topping	O
both	O
the	O
nominally	O
higher-end	O
Quadra	B-Device
950	I-Device
and	O
the	O
Quadra	B-Device
800	I-Device
by	O
7MHz	O
.	O
</s>
<s>
It	O
remains	O
both	O
the	O
fastest	O
Quadra	O
and	O
the	O
fastest	O
68k	B-Device
Macintosh	O
of	O
all	O
time	O
,	O
because	O
all	O
later	O
high-end	O
Macintoshes	O
are	O
PowerPC-based	O
Power	B-Device
Macintoshes	I-Device
.	O
</s>
<s>
The	O
840AV	O
is	O
the	O
only	O
Mac	O
to	O
use	O
the	O
40MHz-clocked	O
68040	B-Device
.	O
</s>
<s>
It	O
sports	O
a	O
faster	O
66.7MHz	O
AT&T	O
DSP	O
3210	O
Digital	B-Architecture
Signal	I-Architecture
Processor	I-Architecture
chip	O
,	O
compared	O
with	O
the	O
55MHz	O
variant	O
in	O
the	O
660AV	O
.	O
</s>
<s>
They	O
are	O
also	O
the	O
first	O
personal	B-Device
computers	I-Device
that	O
supported	O
speech	O
recognition	O
(	O
PlainTalk	O
)	O
out-of-the-box	O
.	O
</s>
<s>
The	O
Apple	O
GeoPort	B-Device
Telecom	O
Adapter	O
Kit	O
introduced	O
with	O
the	O
AV	O
Macs	O
add	O
many	O
DSP-based	O
telecommunication	O
functions	O
,	O
such	O
as	O
modem	O
,	O
fax	O
,	O
and	O
telephony	O
.	O
</s>
<s>
The	O
Quadra	B-Device
840AV	I-Device
has	O
a	O
similar	O
case	O
to	O
the	O
earlier	O
Macintosh	B-Device
Quadra	I-Device
800	I-Device
;	O
the	O
housing	O
,	O
chassis	O
,	O
power	O
supply	O
,	O
and	O
internal	O
storage	O
assemblies	O
are	O
the	O
same	O
,	O
but	O
the	O
front	O
and	O
rear	O
panels	O
changed	O
,	O
with	O
the	O
power	O
button	O
being	O
moved	O
to	O
the	O
front	O
.	O
</s>
<s>
Apart	O
from	O
the	O
faster	O
processor	O
,	O
the	O
logic	O
board	O
lacks	O
the	O
800	O
's	O
Processor	B-Device
Direct	I-Device
Slot	I-Device
and	O
second	O
ADB	O
port	O
,	O
but	O
has	O
a	O
DAV	O
slot	O
(	O
in	O
line	O
with	O
NuBus	O
slot	O
A	O
)	O
and	O
the	O
new	O
GeoPort	B-Device
.	O
</s>
<s>
Also	O
,	O
unlike	O
the	O
800	O
's	O
8MB	O
of	O
fixed	O
RAM	O
,	O
all	O
of	O
the	O
840AV	O
's	O
memory	O
is	O
in	O
SIMMs	B-General_Concept
(	O
this	O
is	O
the	O
reason	O
why	O
the	O
maximum	O
amount	O
of	O
memory	O
is	O
lower	O
)	O
.	O
</s>
<s>
The	O
way	O
in	O
which	O
the	O
840AV	O
deals	O
with	O
its	O
memory	O
(	O
DRAM	O
)	O
differs	O
from	O
the	O
other	O
machines	O
of	O
its	O
generation	O
(	O
Quadra	O
700	O
,	O
800	O
,	O
950	O
)	O
in	O
that	O
4	O
,	O
8	O
,	O
16	O
,	O
or	O
32MB	O
72-pin	O
60ns	O
SIMMs	B-General_Concept
may	O
be	O
installed	O
up	O
to	O
128	O
MB	O
and	O
sizes	O
can	O
be	O
mixed	O
.	O
</s>
<s>
However	O
,	O
the	O
Quadra	B-Device
840AV	I-Device
does	O
not	O
support	O
1MB	O
,	O
2MB	O
,	O
or	O
64MB	O
SIMMs	B-General_Concept
.	O
</s>
<s>
The	O
Quadra	B-Device
840AV	I-Device
was	O
part	O
of	O
a	O
hardware	O
package	O
that	O
was	O
offered	O
with	O
the	O
initial	O
release	O
of	O
Media	O
100	O
.	O
</s>
<s>
Jonathan	O
Chevreau	O
of	O
the	O
National	O
Post	O
said	O
on	O
August	O
7	O
,	O
1993	O
that	O
the	O
Quadra	B-Device
840AV	I-Device
and	O
Centris	B-Device
660AV	I-Device
were	O
the	O
next	O
most	O
interesting	O
multimedia	O
computers	O
behind	O
the	O
new	O
SGI	B-Operating_System
Indy	I-Operating_System
,	O
putting	O
Apple	O
among	O
the	O
forefront	O
of	O
the	O
birth	O
of	O
the	O
major	O
industry	O
of	O
desktop	O
multimedia	O
.	O
</s>
<s>
Ben	O
Thompson	O
of	O
Byte	O
magazine	O
said	O
in	O
September	O
1993	O
that	O
Apple	O
and	O
Silicon	O
Graphics	O
were	O
trailblazers	O
by	O
setting	O
audio	O
and	O
video	O
input	O
as	O
default	O
features	O
of	O
those	O
two	O
Macintosh	O
and	O
of	O
the	O
Indy	B-Operating_System
desktop	O
PCs	B-Device
,	O
which	O
"	O
could	O
change	O
the	O
way	O
businesspeople	O
communicate	O
"	O
.	O
</s>
<s>
He	O
tested	O
the	O
840AV	O
as	O
the	O
overall	O
fastest	O
Macintosh	O
,	O
attributing	O
this	O
to	O
its	O
"	O
radically	O
"	O
new	O
AV	O
series	O
hardware	O
features	O
such	O
as	O
dedicated	O
DMA	O
channels	O
for	O
SCSI	O
,	O
serial	O
,	O
ethernet	O
,	O
and	O
soundbut	O
noted	O
that	O
the	O
SCSI	O
DMA	O
performance	O
is	O
completely	O
lost	O
on	O
the	O
legacy	O
architecture	O
of	O
System	B-Operating_System
7	I-Operating_System
pending	O
a	O
complete	O
microkernel-based	O
rewrite	O
of	O
the	O
operating	O
system	O
such	O
as	O
with	O
Pink	O
or	O
Copland	B-Application
.	O
</s>
