<s>
The	O
DECpc	B-Device
AXP	I-Device
150	I-Device
,	O
code-named	O
Jensen	O
,	O
is	O
an	O
entry-level	O
workstation	B-Device
developed	O
and	O
manufactured	O
by	O
Digital	O
Equipment	O
Corporation	O
.	O
</s>
<s>
Introduced	O
on	O
25	O
May	O
1993	O
,	O
the	O
DECpc	B-Device
AXP	I-Device
150	I-Device
was	O
the	O
first	O
Alpha-based	O
system	O
to	O
support	O
the	O
Windows	B-Device
NT	I-Device
operating	B-General_Concept
system	I-General_Concept
and	O
the	O
basis	O
for	O
the	O
DEC	B-Device
2000	I-Device
AXP	I-Device
entry-level	O
servers	O
.	O
</s>
<s>
It	O
was	O
discontinued	O
on	O
28	O
February	O
1994	O
,	O
succeeded	O
by	O
the	O
entry-level	O
Multia	B-Device
and	O
the	O
entry-level	O
and	O
mid-range	O
models	O
of	O
the	O
AlphaStation	B-Device
family	O
.	O
</s>
<s>
The	O
charter	O
for	O
the	O
development	O
and	O
production	O
of	O
the	O
DEC	B-Device
2000	I-Device
AXP	I-Device
was	O
held	O
by	O
Digital	O
's	O
Entry	O
Level	O
Solutions	O
Business	O
,	O
based	O
in	O
Ayr	O
,	O
Scotland	O
.	O
</s>
<s>
The	O
DEC	B-Device
2000	I-Device
AXP	I-Device
family	O
are	O
entry-level	O
servers	O
based	O
on	O
the	O
DECpc	B-Device
AXP	I-Device
150	I-Device
.	O
</s>
<s>
Differences	O
were	O
support	O
for	O
Digital	O
's	O
OpenVMS	B-Operating_System
AXP	I-Operating_System
and	O
OSF/1	B-Operating_System
AXP	I-Operating_System
(	O
later	O
renamed	O
to	O
Digital	B-Operating_System
UNIX	I-Operating_System
)	O
operating	B-General_Concept
systems	I-General_Concept
and	O
support	O
for	O
a	O
VT-series	B-General_Concept
terminal	I-General_Concept
or	O
equivalent	O
.	O
</s>
<s>
The	O
DEC	B-Device
2000	I-Device
AXP	I-Device
family	O
succeeded	O
by	O
the	O
AlphaServer	B-Device
1000	I-Device
.	O
</s>
<s>
There	O
are	O
two	O
models	O
in	O
the	O
DEC	B-Device
2000	I-Device
AXP	I-Device
family	O
:	O
the	O
Model	O
300	O
and	O
Model	O
500	O
.	O
</s>
<s>
The	O
DEC	B-Device
2000	I-Device
Model	O
300	O
AXP	O
,	O
code-named	O
Jensen	O
,	O
is	O
identical	O
to	O
the	O
DECpc	B-Device
AXP	I-Device
150	I-Device
but	O
was	O
intended	O
to	O
be	O
used	O
as	O
a	O
server	O
.	O
</s>
<s>
Some	O
options	O
available	O
for	O
the	O
DECpc	B-Device
AXP	I-Device
150	I-Device
are	O
not	O
available	O
for	O
the	O
Model	O
300	O
.	O
</s>
<s>
The	O
DEC	B-Device
2000	I-Device
Model	O
500	O
AXP	O
,	O
code-named	O
Culzean	O
,	O
was	O
marketed	O
as	O
a	O
server	O
running	O
either	O
Windows	B-Device
NT	I-Device
Advanced	O
Server	O
,	O
DEC	B-Operating_System
OSF/1	I-Operating_System
AXP	I-Operating_System
or	O
OpenVMS	B-Operating_System
.	O
</s>
<s>
Introduced	O
on	O
15	O
November	O
1993	O
,	O
the	O
Model	O
500	O
was	O
similar	O
to	O
the	O
Model	O
300	O
,	O
but	O
housed	O
in	O
a	O
larger	O
pedestal-type	O
enclosure	O
capable	O
with	O
space	O
for	O
up	O
to	O
12	O
3.5	O
in	O
hard	B-Device
disks	I-Device
and	O
incorporating	O
an	O
Intelligent	O
Front	O
Panel	O
(	O
IFP	O
)	O
for	O
system	O
monitoring	O
and	O
control	O
.	O
</s>
<s>
The	O
DECpc	B-Device
AXP	I-Device
150	I-Device
systems	O
used	O
a	O
150MHz	O
DECchip	B-General_Concept
21064	I-General_Concept
microprocessor	O
with	O
an	O
external	O
512	O
KB	O
B-cache	O
(	O
L2	B-General_Concept
cache	I-General_Concept
)	O
,	O
which	O
is	O
implemented	O
with	O
17	O
nanosecond	O
SRAMs	B-Architecture
located	O
on	O
the	O
motherboard	O
.	O
</s>
<s>
Standard	O
36-bit	O
,	O
70	O
nanosecond	O
SIMMs	B-General_Concept
with	O
longword	O
parity	B-Error_Name
protection	O
are	O
used	O
to	O
populate	O
eight	O
SIMM	B-General_Concept
slots	O
,	O
which	O
are	O
organised	O
in	O
two	O
banks	O
of	O
four	O
slots	O
each	O
.	O
</s>
<s>
The	O
DEC	B-Device
2000	I-Device
AXP	I-Device
supports	O
two	O
memory	O
options	O
,	O
a	O
16	O
MB	O
(	O
4	O
×	O
4	O
MB	O
SIMMs	B-General_Concept
)	O
and	O
a	O
64	O
MB	O
(	O
4	O
×	O
16	O
MB	O
SIMMs	B-General_Concept
)	O
memory	O
kit	O
.	O
</s>
<s>
The	O
DECpc	B-Device
AXP	I-Device
150	I-Device
has	O
six	O
EISA	B-Device
slots	O
for	O
expansion	O
.	O
</s>
<s>
Pre-installed	O
EISA	B-Device
cards	O
typically	O
comprised	O
a	O
Compaq	O
QVision	O
VGA	B-Protocol
adapter	I-Protocol
,	O
Adaptec	O
AHA-1742	O
SCSI	B-Architecture
host	O
adapter	O
,	O
and	O
a	O
DEC	O
DE422	O
Ethernet	O
adapter	O
.	O
</s>
<s>
The	O
DECpc	B-Device
AXP	I-Device
150	I-Device
running	O
Windows	B-Device
NT	I-Device
was	O
intended	O
to	O
be	O
used	O
as	O
a	O
workstation	B-Device
and	O
therefore	O
can	O
only	O
use	O
a	O
VGA	B-Protocol
monitor	I-Protocol
.	O
</s>
<s>
Unlike	O
other	O
similar	O
Alpha	B-Device
systems	O
from	O
Digital	O
at	O
the	O
time	O
,	O
such	O
as	O
the	O
DEC	B-Device
3000	I-Device
AXP	I-Device
,	O
the	O
DECpc	B-Device
AXP	I-Device
150	I-Device
used	O
the	O
EISA	B-Device
bus	I-Device
for	O
expansion	O
instead	O
of	O
the	O
TURBOchannel	B-Device
interconnect	O
.	O
</s>
<s>
The	O
decision	O
to	O
use	O
the	O
EISA	B-Device
bus	I-Device
was	O
due	O
to	O
cost	O
requirements	O
.	O
</s>
<s>
The	O
EISA	B-Device
bus	I-Device
was	O
an	O
industry	O
standard	O
bus	O
,	O
and	O
there	O
were	O
more	O
vendors	O
offering	O
EISA	B-Device
options	O
,	O
in	O
addition	O
to	O
EISA	B-Device
chipsets	O
.	O
</s>
<s>
In	O
contrast	O
,	O
the	O
TURBOchannel	B-Device
bus	O
,	O
while	O
offering	O
higher	O
performance	O
,	O
would	O
have	O
required	O
more	O
expensive	O
ASICs	O
to	O
implement	O
like	O
the	O
DEC	B-Device
3000	I-Device
AXP	I-Device
,	O
and	O
would	O
have	O
reduced	O
the	O
number	O
of	O
third-party	O
options	O
available	O
.	O
</s>
<s>
Because	O
the	O
DECchip	B-General_Concept
21064	I-General_Concept
's	O
signalling	O
is	O
incompatible	O
with	O
the	O
EISA	B-Device
chipset	O
and	O
the	O
system	O
peripherals	O
,	O
the	O
DECchip	O
signals	O
are	O
interfaced	O
to	O
two	O
buses	O
,	O
an	O
address	O
and	O
command	O
bus	O
and	O
a	O
32-bit	O
data	O
bus	O
that	O
masquerades	O
as	O
the	O
80486	B-General_Concept
interfaces	O
.	O
</s>
<s>
These	O
two	O
buses	O
are	O
referred	O
to	O
as	O
"	O
pseudo-486	O
"	O
.	O
</s>
<s>
The	O
EISA	B-Device
bus	I-Device
itself	O
was	O
implemented	O
by	O
a	O
subset	O
of	O
the	O
Intel	O
82350DT	O
chipset	O
.	O
</s>
<s>
The	O
82358	O
EBC	O
(	O
EISA	B-Device
Bus	I-Device
Controller	O
)	O
chip	O
and	O
82357	O
ISP	O
(	O
Integrated	O
System	O
Peripheral	O
)	O
chip	O
implements	O
the	O
EISA	B-Device
bus	I-Device
and	O
provides	O
it	O
with	O
an	O
interface	O
to	O
the	O
system	O
.	O
</s>
<s>
Two	O
82352	O
EBB	O
(	O
EISA	B-Device
Bus	I-Device
Buffer	O
)	O
chips	O
are	O
also	O
present	O
,	O
with	O
one	O
used	O
to	O
interface	O
the	O
EISA	B-Device
bus	I-Device
to	O
a	O
32-bit	O
pseudo-486	O
data	O
bus	O
,	O
and	O
the	O
other	O
used	O
to	O
interface	O
the	O
EISA	B-Device
bus	I-Device
to	O
a	O
pseudo-486	O
address	O
and	O
command	O
bus	O
.	O
</s>
<s>
This	O
arrangement	O
of	O
buffering	O
and	O
converting	O
buses	O
and	O
control	O
signals	O
resulted	O
in	O
an	O
inefficient	O
I/O	O
subsystem	O
and	O
as	O
a	O
result	O
,	O
the	O
EISA	B-Device
bus	I-Device
only	O
achieved	O
a	O
peak	O
bandwidth	O
of	O
25	O
MB/s	O
(	O
compared	O
to	O
33	O
MB/s	O
in	O
standard	O
PCs	O
)	O
.	O
</s>
<s>
A	O
VLSI	O
Technologies	O
VL82C106	O
combination	O
chip	O
,	O
connected	O
to	O
the	O
pseudo-486	O
buses	O
,	O
contains	O
the	O
real	O
time	O
clock	O
and	O
66	O
bytes	B-Application
of	O
battery-backed	O
RAM	O
,	O
in	O
addition	O
to	O
two	O
serial	B-Protocol
ports	I-Protocol
,	O
a	O
parallel	B-Device
port	I-Device
,	O
and	O
two	O
PS/2	B-Protocol
port	I-Protocol
interfaces	O
.	O
</s>
