<s>
DEC	B-Device
3000	I-Device
AXP	I-Device
was	O
the	O
name	O
given	O
to	O
a	O
series	O
of	O
computer	B-Device
workstations	I-Device
and	O
servers	O
,	O
produced	O
from	O
1992	O
to	O
around	O
1995	O
by	O
Digital	O
Equipment	O
Corporation	O
.	O
</s>
<s>
The	O
DEC	B-Device
3000	I-Device
AXP	I-Device
series	O
formed	O
part	O
of	O
the	O
first	O
generation	O
of	O
computer	O
systems	O
based	O
on	O
the	O
64-bit	O
Alpha	B-Device
AXP	I-Device
architecture	O
.	O
</s>
<s>
Supported	O
operating	B-General_Concept
systems	I-General_Concept
for	O
the	O
DEC	B-Device
3000	I-Device
AXP	I-Device
series	O
were	O
DEC	B-Operating_System
OSF/1	I-Operating_System
AXP	I-Operating_System
(	O
later	O
renamed	O
Digital	B-Operating_System
UNIX	I-Operating_System
)	O
and	O
OpenVMS	B-Operating_System
AXP	O
(	O
later	O
renamed	O
OpenVMS	B-Operating_System
)	O
.	O
</s>
<s>
All	O
DEC	B-Device
3000	I-Device
AXP	I-Device
models	O
used	O
the	O
DECchip	B-General_Concept
21064	I-General_Concept
(	O
EV4	O
)	O
or	O
DECchip	B-General_Concept
21064A	I-General_Concept
(	O
EV45	O
)	O
processor	O
and	O
inherited	O
various	O
features	O
from	O
the	O
earlier	O
MIPS	O
architecture-based	O
DECstation	B-Device
models	O
,	O
such	O
as	O
the	O
TURBOchannel	B-Device
bus	B-General_Concept
and	O
the	O
I/O	O
subsystem	O
.	O
</s>
<s>
The	O
DEC	B-Device
3000	I-Device
AXP	I-Device
series	O
was	O
superseded	O
in	O
late	O
1994	O
,	O
with	O
workstation	B-Device
models	O
replaced	O
by	O
the	O
AlphaStation	B-Device
line	O
and	O
server	B-Application
models	O
replaced	O
by	O
the	O
AlphaServer	B-Device
line	O
.	O
</s>
<s>
There	O
were	O
three	O
DEC	B-Device
3000	I-Device
model	O
families	O
,	O
codenamed	O
Pelican	O
,	O
Sandpiper	O
,	O
and	O
Flamingo	O
.	O
</s>
<s>
Within	O
Digital	O
,	O
this	O
led	O
to	O
the	O
DEC	B-Device
3000	I-Device
series	O
being	O
affectionately	O
referred	O
to	O
as	O
"	O
the	O
seabirds	O
"	O
.	O
</s>
<s>
Model	O
Codename	O
CPU	O
CPU	O
MHz	O
B-cache	O
(	O
L2	O
)	O
Chassis	O
Introduced	O
Withdrawn	O
Model	O
300	O
Pelican	O
EV4	O
150	O
256	O
KB	O
Desktop	O
1993-04-20	O
?	O
</s>
<s>
Note	O
:	O
Server	B-Application
configurations	O
of	O
the	O
Model	O
400/500/600/700/800/900	O
systems	O
were	O
suffixed	O
with	O
"	O
S	O
"	O
.	O
</s>
<s>
The	O
CPU	O
module	O
is	O
a	O
daughterboard	O
that	O
plugs	O
into	O
the	O
system	O
module	O
and	O
contains	O
the	O
CPU	O
and	O
the	O
B-cache	O
(	O
L2	O
cache	O
)	O
.	O
</s>
<s>
The	O
architecture	O
of	O
the	O
Flamingo	O
-	O
and	O
Sandpiper-based	O
systems	O
is	O
based	O
around	O
a	O
crossbar	O
switch	O
implemented	O
by	O
an	O
ADDR	O
(	O
Address	O
)	O
ASIC	O
,	O
four	O
SLICE	O
(	O
data	O
slice	O
)	O
ASICs	O
and	O
a	O
TC	O
(	O
TURBOchannel	B-Device
)	O
ASIC	O
.	O
</s>
<s>
The	O
cache	O
,	O
memory	O
and	O
TURBOchannel	B-Device
controllers	O
,	O
as	O
well	O
as	O
other	O
control	O
logic	O
,	O
is	O
entirely	O
implemented	O
by	O
PALs	O
.	O
</s>
<s>
Pelican-based	O
systems	O
have	O
an	O
entirely	O
different	O
architecture	O
from	O
the	O
other	O
systems	O
,	O
similar	O
to	O
that	O
of	O
late-model	O
Personal	B-Device
DECstations	I-Device
that	O
they	O
are	O
based	O
on	O
,	O
with	O
a	O
traditional	O
workstation	B-Device
architecture	O
with	O
buses	O
and	O
buffers	O
.	O
</s>
<s>
The	O
Sandpiper	O
and	O
Flamingo	O
used	O
proprietary	O
100-pin	O
,	O
40-bit	O
(	O
32	O
bits	O
plus	O
8	O
bits	O
ECC	O
)	O
Fast	O
Page	O
Mode	O
SIMMs	B-General_Concept
with	O
capacities	O
of	O
2MB	O
,	O
4MB	O
,	O
8MB	O
,	O
16MB	O
or	O
32MB	O
.	O
</s>
<s>
These	O
were	O
eight-way	O
interleaved	O
,	O
providing	O
a	O
256-bit-wide	O
bus	B-General_Concept
to	O
memory	O
.	O
</s>
<s>
The	O
Sandpiper	O
had	O
two	O
such	O
eight-SIMM	O
banks	O
,	O
for	O
up	O
to	O
512	O
MB	O
total	O
system	O
RAM	O
,	O
while	O
the	O
Flamingo	O
had	O
four	O
banks	O
and	O
supported	O
up	O
to	O
1	O
GB	O
.	O
</s>
<s>
In	O
comparison	O
,	O
the	O
Pelican	O
was	O
a	O
budget	O
architecture	O
utilising	O
eight	O
standard	O
72-pin	O
Fast	O
Page	O
Mode	O
SIMMs	B-General_Concept
that	O
were	O
protected	O
with	O
longword	O
parity	O
instead	O
of	O
ECC	O
,	O
with	O
capacities	O
of	O
8MB	O
or	O
32MB	O
,	O
for	O
a	O
total	O
of	O
up	O
to	O
256MB	O
RAM	O
.	O
</s>
<s>
These	O
were	O
two-way	O
interleaved	O
,	O
for	O
a	O
64-bit-wide	O
bus	B-General_Concept
to	O
memory	O
.	O
</s>
<s>
The	O
DEC	B-Device
3000	I-Device
AXP	I-Device
series	O
uses	O
the	O
32-bit	O
TURBOchannel	B-Device
bus	B-General_Concept
running	O
at	O
various	O
speeds	O
,	O
12.5MHz	O
in	O
the	O
300	O
models	O
,	O
22.5MHz	O
in	O
the	O
400	O
models	O
and	O
25MHz	O
in	O
models	O
500	O
to	O
900	O
.	O
</s>
<s>
The	O
TURBOchannel	B-Device
bus	B-General_Concept
is	O
provided	O
by	O
an	O
ASIC	O
,	O
which	O
connected	O
it	O
to	O
the	O
SLICE	O
data	O
path	O
ASICs	O
.	O
</s>
<s>
This	O
subsystem	O
is	O
essentially	O
an	O
onboard	O
HX	O
TURBOchannel	B-Device
option	O
module	O
.	O
</s>
<s>
The	O
subsystem	O
features	O
a	O
SFB	O
(	O
smart	O
frame	B-Algorithm
buffer	I-Algorithm
)	O
ASIC	O
,	O
a	O
Brooktree	O
Bt459	O
RAMDAC	B-Device
,	O
2	O
MB	O
of	O
VRAM	O
and	O
in	O
the	O
Model	O
500	O
,	O
500S	O
and	O
500X	O
,	O
a	O
256	O
KB	O
flash	B-Device
ROM	I-Device
that	O
holds	O
part	O
of	O
the	O
system	O
firmware	O
.	O
</s>
<s>
Because	O
of	O
the	O
DEC	B-Device
3000	I-Device
AXP	I-Device
's	O
similarity	O
with	O
Digital	O
's	O
previous	O
RISC	O
workstation	B-Device
line	O
,	O
the	O
DECstation	B-Device
,	O
the	O
same	O
TURBOchannel	B-Device
graphics	O
options	O
,	O
which	O
consisted	O
of	O
framebuffers	B-Algorithm
,	O
2D	O
and	O
3D	O
accelerated	O
graphics	O
,	O
were	O
carried	O
over	O
the	O
DEC	B-Device
3000	I-Device
AXP	I-Device
.	O
</s>
<s>
Like	O
the	O
DECstation	B-Device
,	O
up	O
to	O
three	O
(	O
the	O
actual	O
number	O
may	O
be	O
less	O
,	O
depending	O
on	O
the	O
number	O
of	O
TURBOchannel	B-Device
option	O
slots	O
the	O
system	O
features	O
)	O
framebuffers	B-Algorithm
of	O
the	O
same	O
model	O
can	O
be	O
installed	O
in	O
a	O
single	O
system	O
to	O
support	O
multiscreen	B-General_Concept
configurations	O
.	O
</s>
<s>
Despite	O
using	O
the	O
same	O
graphics	O
options	O
as	O
the	O
DECstation	B-Device
at	O
introduction	O
,	O
later	O
options	O
for	O
the	O
DEC	B-Device
3000	I-Device
AXP	I-Device
were	O
designed	O
exclusively	O
for	O
the	O
platform	O
.	O
</s>
<s>
It	O
connects	O
to	O
the	O
DEC	B-Device
3000	I-Device
AXP	I-Device
via	O
a	O
cable	O
and	O
a	O
TURBOchannel	B-Device
interface	O
module	O
.	O
</s>
<s>
The	O
I/O	O
subsystem	O
provides	O
the	O
DEC	B-Device
3000	I-Device
AXP	I-Device
with	O
Ethernet	O
,	O
ISDN	B-Protocol
and	O
audio	O
capability	O
,	O
four	O
serial	O
lines	O
,	O
and	O
a	O
real-time	O
clock	O
.	O
</s>
<s>
The	O
I/O	O
subsystem	O
is	O
interfaced	O
to	O
TURBOchannel	B-Device
by	O
the	O
IOCTL	O
ASIC	O
,	O
which	O
also	O
implements	O
two	O
8-bit	O
buses	O
,	O
known	O
as	O
IOBUS	O
HI	O
and	O
IOBUS	O
LO	O
,	O
to	O
which	O
the	O
I/O	O
devices	O
connect	O
to	O
.	O
</s>
<s>
These	O
two	O
8-bit	O
buses	O
can	O
be	O
combined	O
to	O
serve	O
as	O
one	O
16-bit	O
bus	B-General_Concept
to	O
provide	O
an	O
I/O	O
device	O
with	O
more	O
bandwidth	O
.	O
</s>
<s>
ISDN	B-Protocol
and	O
telephone-quality	O
audio	O
is	O
provided	O
by	O
an	O
AMD	O
Am79C30A	O
DSC	O
(	O
Digital	O
Subscriber	O
Controller	O
)	O
.	O
</s>
<s>
The	O
DEC	B-Device
3000	I-Device
AXP	I-Device
used	O
a	O
TCDS	O
(	O
TURBOchannel	B-Device
Dual	O
SCSI	B-Architecture
)	O
ASIC	O
to	O
provide	O
an	O
interface	O
between	O
the	O
SCSI	B-Architecture
controllers	O
and	O
the	O
TURBOchannel	B-Device
bus	B-General_Concept
.	O
</s>
<s>
Early	O
systems	O
used	O
one	O
(	O
Model	O
300s	O
)	O
or	O
two	O
(	O
Model	O
400	O
and	O
500	O
)	O
NCR	O
53C94	O
SCSI	B-Architecture
controllers	O
,	O
which	O
provided	O
one	O
or	O
two	O
5	O
MB/s	O
8-bit	O
single	O
ended	O
SCSI	B-Architecture
buses	O
.	O
</s>
<s>
Later	O
and	O
higher	O
end	O
systems	O
such	O
as	O
the	O
Model	O
600	O
,	O
700	O
,	O
800	O
and	O
900	O
also	O
feature	O
two	O
SCSI	B-Architecture
controllers	O
,	O
but	O
used	O
the	O
NCR	O
53CF94-2	O
instead	O
,	O
which	O
provided	O
faster	O
10	O
MB/s	O
8-bit	O
single	O
ended	O
SCSI	B-Architecture
buses	O
.	O
</s>
