<s>
The	O
Tandy	B-Device
3000	I-Device
is	O
a	O
personal	B-Device
computer	I-Device
introduced	O
by	O
Radio	O
Shack	O
in	O
1986	O
based	O
on	O
the	O
16-bit	O
8MHz	O
Intel	B-General_Concept
80286	I-General_Concept
microprocessor	B-Architecture
.	O
</s>
<s>
The	O
Tandy	B-Device
3000	I-Device
is	O
functionally	O
a	O
clone	O
of	O
the	O
IBM	B-Operating_System
PC-AT	I-Operating_System
,	O
the	O
first	O
PC	O
by	O
a	O
major	O
manufacturer	O
using	O
the	O
fully	O
16-bit	O
Intel	B-General_Concept
286	I-General_Concept
processor	O
.	O
</s>
<s>
As	O
such	O
,	O
it	O
departed	O
from	O
Tandy	O
's	O
two	O
previous	O
PC	O
workalikes	O
(	O
the	O
Tandy	B-Device
2000	I-Device
in	O
1983	O
and	O
the	O
Tandy	O
1000	O
in	O
1985	O
)	O
in	O
that	O
it	O
was	O
built	O
without	O
proprietary	O
technology	O
.	O
</s>
<s>
The	O
operating	O
system	O
was	O
an	O
extra-cost	O
item	O
;	O
the	O
purchaser	O
could	O
choose	O
MS-DOS	B-Application
3.2	O
or	O
Xenix	B-Application
V	O
.	O
Xenix	B-Application
and	O
the	O
extra	O
memory	O
it	O
demanded	O
was	O
expensive	O
but	O
permitted	O
up	O
to	O
six	O
remote	O
terminals	O
to	O
run	O
programs	O
on	O
a	O
single	O
Tandy	B-Device
3000	I-Device
simultaneously	O
.	O
</s>
<s>
Microsoft	O
's	O
BASIC	O
interpreter	O
,	O
bundled	O
with	O
Tandy	O
's	O
Deskmate	B-Device
productivity	O
suite	O
,	O
was	O
offered	O
at	O
extra	O
cost	O
.	O
</s>
<s>
Digital	O
Research	O
's	O
CP/M	B-Operating_System
-86	I-Operating_System
was	O
an	O
option	O
available	O
from	O
other	O
software	O
vendors	O
.	O
</s>
<s>
Later	O
,	O
others	O
available	O
for	O
generic	O
AT	O
clones	O
such	O
as	O
the	O
Tandy	B-Device
3000	I-Device
included	O
IBM	O
's	O
PC	B-Operating_System
DOS	I-Operating_System
,	O
Digital	O
Research	O
's	O
DR-DOS	B-Application
and	O
GEM	B-Application
,	O
and	O
16-bit	O
versions	O
of	O
Microsoft	O
's	O
Windows	O
(	O
up	O
to	O
version	O
3.x	O
)	O
.	O
</s>
<s>
Still	O
later	O
IBM	O
's	O
graphical	O
multitasking	O
OS/2	B-Application
was	O
an	O
option	O
for	O
machines	O
equipped	O
with	O
enough	O
memory	O
and	O
capable	O
graphics	O
display	O
hardware	O
.	O
</s>
<s>
The	O
Tandy	B-Device
3000	I-Device
has	O
ten	O
expansion	O
slots	O
:	O
seven	O
16-bit	O
AT	O
compatible	O
,	O
two	O
8-bit	O
XT	O
compatible	O
,	O
and	O
one	O
half-size	O
XT	O
slot	O
dedicated	O
to	O
the	O
included	O
serial/parallel	O
card	O
.	O
</s>
<s>
There	O
are	O
three	O
drive	O
bays	O
available	O
;	O
two	O
are	O
accessible	O
through	O
the	O
front	O
panel	O
,	O
so	O
two	O
may	O
be	O
floppy	O
drives	O
or	O
other	O
replaceable	O
media	O
like	O
a	O
PCMCIA	B-Architecture
card	I-Architecture
reader	O
.	O
</s>
<s>
Like	O
IBM	O
's	O
later	O
PS/2	B-Device
series	O
and	O
other	O
newer	O
computers	O
in	O
the	O
industry	O
,	O
Tandy	O
's	O
follow-on	O
computers	O
would	O
discontinue	O
using	O
this	O
drive	O
and	O
switch	O
to	O
the	O
3.5	O
inch	O
format	O
.	O
</s>
<s>
In	O
later	O
years	O
drives	O
with	O
capacities	O
far	O
greater	O
than	O
35	O
MB	O
became	O
available	O
for	O
installation	O
,	O
though	O
the	O
MS-DOS	B-Application
3.2	O
most	O
often	O
purchased	O
with	O
the	O
computer	O
could	O
not	O
manage	O
so	O
much	O
storage	O
without	O
partitioning	O
.	O
</s>
<s>
The	O
Tandy	B-Device
3000	I-Device
has	O
a	O
smaller	O
desk	O
footprint	O
than	O
the	O
AT	O
;	O
it	O
occupies	O
342	O
square	O
inches	O
(	O
19	O
by	O
18	O
inches	O
)	O
which	O
is	O
less	O
than	O
the	O
AT	O
's	O
footprint	O
of	O
367.2	O
square	O
inches	O
(	O
21.25	O
by	O
17.28	O
inches	O
)	O
.	O
</s>
<s>
Two	O
years	O
after	O
its	O
introduction	O
,	O
the	O
Tandy	B-Device
3000	I-Device
was	O
improved	O
with	O
a	O
286	B-General_Concept
processor	O
that	O
ran	O
at	O
a	O
clock	O
rate	O
of	O
12	O
MHz	O
,	O
which	O
could	O
be	O
switched	O
to	O
6	O
MHz	O
.	O
</s>
<s>
The	O
motherboard	O
was	O
revised	O
to	O
permit	O
up	O
to	O
16	O
MB	O
of	O
RAM	O
in	O
the	O
expansion	O
slots	O
,	O
the	O
most	O
memory	O
the	O
286	B-General_Concept
chip	O
could	O
address	O
.	O
</s>
<s>
In	O
1990	O
Tandy	O
updated	O
the	O
3000	O
NL	O
's	O
motherboard	O
with	O
built-in	O
VGA	B-Protocol
circuitry	O
,	O
obviating	O
the	O
need	O
to	O
install	O
a	O
video	O
card	O
in	O
an	O
expansioni	O
slot	O
.	O
</s>
<s>
One	O
megabyte	O
of	O
RAM	O
comes	O
installed	O
,	O
and	O
using	O
expansion	O
slots	O
RAM	O
can	O
go	O
to	O
16	O
megabytes	O
(	O
the	O
maximum	O
addressable	O
by	O
the	O
286	B-General_Concept
)	O
.	O
</s>
<s>
By	O
this	O
time	O
the	O
new	O
Intel	O
80386SX	O
processor	O
,	O
with	O
its	O
16-bit	O
external	O
data	O
bus	O
,	O
24-bit	O
address	O
bus	O
and	O
32-bit	O
processor	O
core	O
,	O
enabled	O
PC	O
makers	O
to	O
offer	O
performance	O
superior	O
to	O
the	O
286/PC	O
-AT	O
at	O
more	O
affordable	O
prices	O
.	O
</s>
<s>
Accordingly	O
,	O
starting	O
in	O
1991	O
,	O
Tandy	O
followed	O
the	O
industry	O
trend	O
of	O
substituting	O
computers	O
using	O
it	O
for	O
products	O
based	O
on	O
the	O
286/PC	O
-AT	O
technology	O
.	O
</s>
<s>
Consequently	O
the	O
new	O
4016	O
and	O
4020	O
SX	O
computers	O
replaced	O
the	O
2500	O
XL	O
,	O
leaving	O
only	O
the	O
1000	O
TL	O
(	O
and	O
later	O
the	O
1000	O
RLX	O
)	O
line	O
of	O
desktops	O
to	O
continue	O
using	O
the	O
286	B-General_Concept
processor	O
,	O
which	O
had	O
8-bit	O
XT	O
expansion	O
slots	O
,	O
not	O
16-bit	O
AT	O
compatible	O
slots	O
.	O
</s>
<s>
Further	O
,	O
the	O
1000s	O
could	O
not	O
run	O
the	O
graphical	O
multitasking	O
OS/2	B-Application
operating	O
system	O
,	O
as	O
could	O
the	O
3000	O
and	O
2500	O
XL	O
.	O
</s>
<s>
In	O
1992	O
Tandy	O
offered	O
an	O
upgraded	O
2500	O
XL	O
with	O
its	O
286	B-General_Concept
processor	O
clocked	O
at	O
16	O
MHz	O
and	O
a	O
Super	O
VGA	B-Protocol
(	O
maximum	O
pixel	O
resolution	O
of	O
1024	O
by	O
768	O
)	O
video	O
card	O
built	O
into	O
the	O
motherboard	O
.	O
</s>
