<s>
The	O
Amiga	B-Device
4000	I-Device
,	O
or	O
A4000	O
,	O
from	O
Commodore	O
is	O
the	O
successor	O
of	O
the	O
Amiga	B-Device
2000	I-Device
and	O
Amiga	B-Device
3000	I-Device
computers	O
.	O
</s>
<s>
There	O
are	O
two	O
models	O
:	O
the	O
A4000/040	O
released	O
in	O
October	O
1992	O
with	O
a	O
Motorola	B-Device
68040	I-Device
CPU	B-General_Concept
,	O
and	O
the	O
A4000/030	O
released	O
in	O
April	O
1993	O
with	O
a	O
Motorola	O
68EC030	O
.	O
</s>
<s>
The	O
Amiga	B-Device
4000	I-Device
system	O
design	O
was	O
generally	O
similar	O
to	O
that	O
of	O
the	O
A3000	O
,	O
but	O
introduced	O
the	O
Advanced	B-Device
Graphics	I-Device
Architecture	I-Device
(	O
AGA	O
)	O
chipset	O
with	O
enhanced	O
graphics	O
.	O
</s>
<s>
The	O
SCSI	B-Architecture
system	O
from	O
previous	O
Amigas	O
was	O
replaced	O
by	O
the	O
lower-cost	O
Parallel	B-Protocol
ATA	I-Protocol
.	O
</s>
<s>
Later	O
,	O
Commodore	O
released	O
an	O
expanded	O
tower	B-General_Concept
version	O
called	O
the	O
A4000T	B-Device
.	O
</s>
<s>
The	O
stock	O
A4000	O
shipped	O
with	O
either	O
a	O
Motorola	O
68EC030	O
or	O
68040	B-Device
CPU	B-General_Concept
,	O
2MB	O
of	O
Amiga	B-Device
Chip	I-Device
RAM	I-Device
and	O
up	O
to	O
16MB	O
of	O
additional	O
RAM	B-Architecture
in	O
32-bit	O
SIMMs	B-General_Concept
.	O
</s>
<s>
There	O
is	O
a	O
non-functional	O
jumper	O
that	O
was	O
intended	O
to	O
expand	O
the	O
"	O
chip	B-Device
RAM	I-Device
"	O
to	O
8MB	O
.	O
</s>
<s>
Later	O
,	O
third-party	O
developers	O
created	O
various	O
CPU	B-General_Concept
expansion	O
boards	O
featuring	O
higher-rated	O
68040	B-Device
,	O
68060	B-General_Concept
and	O
PowerPC	B-Architecture
CPUs	O
.	O
</s>
<s>
Such	O
hardware	O
also	O
typically	O
offers	O
faster	O
and	O
higher-capacity	O
RAM	B-Architecture
(	O
128MB	O
or	O
greater	O
)	O
.	O
</s>
<s>
Unlike	O
previous	O
Amiga	B-Device
models	I-Device
,	O
early	O
A4000	O
machines	O
have	O
the	O
CPU	B-General_Concept
mounted	O
in	O
an	O
expansion	O
board	O
;	O
the	O
motherboard	B-Device
does	O
not	O
have	O
an	O
integrated	O
CPU	B-General_Concept
.	O
</s>
<s>
Later	O
revisions	O
of	O
the	O
A4000	O
have	O
the	O
CPU	B-General_Concept
and	O
2MB	O
RAM	B-Architecture
surface-mounted	O
on	O
the	O
motherboard	B-Device
in	O
an	O
effort	O
to	O
reduce	O
costs	O
.	O
</s>
<s>
These	O
machines	O
are	O
known	O
as	O
the	O
A4000-CR	O
(	O
cost-reduced	O
)	O
and	O
the	O
surface-mounted	O
CPU	B-General_Concept
is	O
a	O
68EC030	O
.	O
</s>
<s>
The	O
A4000	O
is	O
the	O
first	O
Amiga	O
model	O
to	O
have	O
shipped	O
with	O
Commodore	O
's	O
third-generation	O
Amiga	O
chipset	O
,	O
the	O
32-bit	O
Advanced	B-Device
Graphics	I-Device
Architecture	I-Device
(	O
AGA	O
)	O
.	O
</s>
<s>
The	O
on-board	O
sound	O
hardware	O
remains	O
identical	O
to	O
that	O
of	O
the	O
original	O
Amiga	O
chipset	O
(	O
the	O
Paula	O
sound	O
chip	O
)	O
,	O
namely	O
,	O
four	O
DMA-driven	O
8-bit	O
PCM	B-Algorithm
channels	O
,	O
with	O
two	O
channels	O
for	O
the	O
left	O
speaker	O
and	O
two	O
for	O
the	O
right	O
.	O
</s>
<s>
The	O
A4000	O
has	O
a	O
number	O
of	O
Amiga-specific	O
connectors	O
,	O
including	O
two	O
DE-9	B-Protocol
ports	O
for	O
joysticks	B-Device
,	O
mice	B-Device
,	O
and	O
light	B-Device
pens	I-Device
,	O
a	O
standard	O
25-pin	O
RS-232	O
serial	B-Protocol
port	I-Protocol
and	O
a	O
25-pin	O
Centronics	O
parallel	B-Device
port	I-Device
.	O
</s>
<s>
As	O
a	O
result	O
,	O
at	O
launch	O
the	O
A4000	O
was	O
compatible	O
with	O
many	O
existing	O
Amiga	O
peripherals	O
,	O
such	O
as	O
MIDI	O
devices	O
,	O
serial	O
modems	B-Application
and	O
sound	B-Algorithm
samplers	I-Algorithm
.	O
</s>
<s>
Like	O
the	O
just-earlier	O
Amiga	O
model	O
,	O
the	O
3000	B-Device
,	O
the	O
A4000	O
has	O
four	O
internal	O
32-bit	O
Zorro	B-Device
III	I-Device
expansion	O
slots	O
.	O
</s>
<s>
This	O
expansion	O
bus	O
allows	O
the	O
use	O
of	O
devices	O
which	O
comply	O
with	O
the	O
AutoConfig	B-Device
standard	O
,	O
such	O
as	O
graphic	O
cards	O
,	O
audio	O
cards	O
,	O
network	O
cards	O
,	O
SCSI	B-Architecture
controllers	O
,	O
and	O
later	O
even	O
USB	B-Protocol
controllers	O
.	O
</s>
<s>
One	O
of	O
the	O
most	O
notable	O
hardware	O
items	O
of	O
the	O
era	O
is	O
the	O
NewTek	B-Device
Video	I-Device
Toaster	I-Device
system	O
which	O
became	O
popular	O
in	O
the	O
1990s	O
for	O
amateur	O
and	O
commercial	O
desktop	O
video	O
production	O
of	O
standard-definition	B-Device
broadcast	O
quality	O
video	O
,	O
consisting	O
of	O
tools	O
for	O
video	O
switching	O
,	O
chroma	O
keying	O
,	O
character	O
generation	O
,	O
animation	O
,	O
and	O
image	B-Application
manipulation	I-Application
.	O
</s>
<s>
The	O
three	O
ISA	B-Architecture
slots	I-Architecture
can	O
be	O
activated	O
by	O
use	O
of	O
a	O
bridgeboard	O
,	O
which	O
connects	O
the	O
Zorro	O
and	O
ISA	B-Architecture
buses	O
.	O
</s>
<s>
Such	O
bridgeboards	O
typically	O
feature	O
on-board	O
IBM-PC-compatible	O
hardware	O
,	O
including	O
Intel	B-General_Concept
80286	I-General_Concept
,	O
80386	B-General_Concept
,	O
or	O
80486	B-General_Concept
microprocessors	O
allowing	O
emulation	O
of	O
an	O
entire	O
IBM-PC	O
system	O
in	O
hardware	O
.	O
</s>
<s>
Compatible	O
ISA	B-Architecture
cards	I-Architecture
may	O
then	O
be	O
installed	O
into	O
the	O
two	O
remaining	O
ISA	B-Architecture
slots	I-Architecture
.	O
</s>
<s>
Later	O
,	O
in	O
an	O
effort	O
to	O
offer	O
modern	O
expansion	O
options	O
third-party	O
developers	O
created	O
replacement	O
expansion	O
boards	O
for	O
the	O
A4000	O
which	O
provide	O
PCI	B-Protocol
slots	I-Protocol
allowing	O
use	O
of	O
higher	O
performance	O
and	O
widely	O
available	O
PCI	B-Protocol
hardware	O
,	O
such	O
as	O
graphic	O
,	O
sound	O
,	O
and	O
network	O
cards	O
.	O
</s>
<s>
The	O
A4000	O
shipped	O
with	O
AmigaOS	B-Application
3.0	O
,	O
consisting	O
of	O
Workbench	O
3.0	O
and	O
Kickstart	B-Device
3.0	O
,	O
which	O
together	O
provide	O
a	O
single-user	O
multi-tasking	O
operating	B-General_Concept
system	I-General_Concept
and	O
support	O
for	O
the	O
built-in	O
hardware	O
.	O
</s>
<s>
Following	O
release	O
of	O
AmigaOS	B-Application
3.1	O
it	O
became	O
possible	O
to	O
upgrade	O
the	O
A4000	O
by	O
installing	O
compatible	O
Kickstart	B-Device
3.1	O
ROM	B-Device
chips	I-Device
.	O
</s>
<s>
The	O
later	O
AmigaOS	B-Application
3.5	O
and	O
3.9	O
releases	O
were	O
software-only	O
updates	O
requiring	O
Kickstart	B-Device
3.1	O
.	O
</s>
<s>
AmigaOS	B-Application
4	I-Application
,	O
a	O
PowerPC-native	O
release	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
can	O
be	O
used	O
with	O
the	O
A4000	O
provided	O
a	O
CyberStorm	O
PPC	O
board	O
is	O
installed	O
.	O
</s>
<s>
Likewise	O
,	O
MorphOS	B-Operating_System
,	O
an	O
alternative	O
Amiga-compatible	O
operating	B-General_Concept
system	I-General_Concept
,	O
can	O
be	O
used	O
with	O
this	O
hardware	O
.	O
</s>
<s>
Variants	O
of	O
platform-independent	O
operating	B-General_Concept
systems	I-General_Concept
,	O
such	O
as	O
Linux	B-Application
and	O
BSD	B-Operating_System
,	O
can	O
also	O
be	O
used	O
with	O
the	O
A4000	O
.	O
</s>
