<s>
The	O
IBM	B-Device
5120	I-Device
Computing	O
System	O
(	O
sometimes	O
referred	O
to	O
as	O
the	O
IBM	B-Device
5110	I-Device
Model	O
3	O
)	O
was	O
announced	O
in	O
February	O
1980	O
as	O
the	O
desktop	O
follow-on	O
to	O
the	O
IBM	B-Device
5110	I-Device
Computing	O
System	O
.	O
</s>
<s>
It	O
featured	O
two	O
built-in	O
8-inch	O
1.2	O
MB	O
floppy	B-Device
disk	I-Device
drives	I-Device
,	O
9-inch	O
monochrome	B-Device
monitor	I-Device
,	O
32KB	O
RAM	B-Architecture
and	O
optional	O
IBM	O
5114	O
stand-alone	O
diskette	B-Device
unit	O
with	O
two	O
additional	O
8-inch	O
1.2	O
MB	O
floppy	B-Device
disk	I-Device
drives	I-Device
.	O
</s>
<s>
The	O
system	O
was	O
sold	O
with	O
both	O
APL	B-Language
and	O
BASIC	O
languages	O
in	O
ROM	B-Device
and	O
provided	O
a	O
toggle	O
switch	O
on	O
the	O
front	O
panel	O
to	O
select	O
the	O
language	O
.	O
</s>
<s>
APL	B-Language
allowed	O
numerous	O
business	O
software	O
written	O
on	O
IBM	O
minicomputers	B-Architecture
to	O
run	O
on	O
the	O
5120	O
.	O
</s>
<s>
Aside	O
from	O
larger	O
screen	O
size	O
and	O
performance	O
benefits	O
over	O
its	O
predecessor	O
,	O
the	O
IBM	B-Device
5120	I-Device
design	O
incorporated	O
several	O
usability	B-General_Concept
advantages	O
:	O
</s>
<s>
For	O
its	O
usability	B-General_Concept
features	O
and	O
appearance	O
,	O
the	O
IBM	B-Device
5120	I-Device
was	O
recognized	O
with	O
two	O
major	O
industrial	O
design	O
awards	O
and	O
described	O
with	O
terms	O
such	O
as	O
"	O
clean	O
,	O
well	O
thought	O
out	O
"	O
;	O
"	O
subtle	O
detailing	O
shows	O
great	O
care	O
in	O
execution	O
"	O
;	O
and	O
"	O
looks	O
like	O
quality″	O
.	O
</s>
<s>
IBM	O
did	O
not	O
offer	O
a	O
LAN	B-General_Concept
or	O
hard	B-Device
disk	I-Device
drive	I-Device
for	O
these	O
systems	O
.	O
</s>
<s>
However	O
,	O
in	O
1981	O
,	O
Hal	O
Prewitt	O
,	O
founder	O
of	O
Core	O
International	O
,	O
Inc	O
,	O
invented	O
and	O
marketed	O
the	O
world	O
's	O
first	O
and	O
only	O
hard	B-Device
disk	I-Device
subsystems	O
and	O
"	O
CoreNet	O
"	O
,	O
a	O
LAN	B-General_Concept
used	O
to	O
share	O
programs	O
and	O
data	O
for	O
the	O
IBM	B-Device
5110	I-Device
and	O
5120	O
systems	O
.	O
</s>
<s>
In	O
1984	O
,	O
Core	O
introduced	O
PC51	O
,	O
software	O
that	O
allowed	O
5100	O
Series	O
computer	O
programs	O
written	O
in	O
BASIC	O
to	O
run	O
unmodified	O
on	O
the	O
IBM	B-Device
PC	I-Device
and	O
compatibles	O
under	O
PC	B-Operating_System
DOS	I-Operating_System
and	O
share	O
programs	O
and	O
data	O
on	O
CoreNet	O
,	O
the	O
LAN	B-General_Concept
for	O
all	O
these	O
models	O
.	O
</s>
