<s>
The	O
Macintosh	B-Device
IIx	I-Device
is	O
a	O
personal	B-Device
computer	I-Device
designed	O
,	O
manufactured	O
,	O
and	O
sold	O
by	O
Apple	O
Computer	O
from	O
September	O
1988	O
to	O
October	O
1990	O
.	O
</s>
<s>
This	O
model	O
was	O
introduced	O
as	O
an	O
update	O
to	O
the	O
original	O
Macintosh	B-Device
II	I-Device
,	O
replacing	O
the	O
16MHz	O
Motorola	B-Device
68020	I-Device
CPU	O
and	O
68881	B-General_Concept
FPU	O
with	O
a	O
68030	B-Device
CPU	O
and	O
68882	B-General_Concept
FPU	O
running	O
at	O
the	O
same	O
clock	O
speed	O
.	O
</s>
<s>
The	O
800	O
KB	O
floppy	B-Device
drive	I-Device
was	O
replaced	O
with	O
a	O
1.44	O
MB	O
SuperDrive	B-Device
;	O
the	O
IIx	O
is	O
the	O
first	O
Macintosh	B-Device
to	O
include	O
this	O
as	O
standard	O
.	O
</s>
<s>
The	O
Mac	B-Device
IIx	O
included	O
0.25	O
KiB	O
of	O
L1	O
instruction	O
CPU	B-General_Concept
cache	I-General_Concept
,	O
0.25	O
KiB	O
of	O
L1	O
data	B-General_Concept
cache	I-General_Concept
,	O
a	O
16MHz	O
bus	O
(	O
1:1	O
with	O
CPU	O
speed	O
)	O
,	O
and	O
supported	O
up	O
to	O
System	B-Operating_System
7.5.5	I-Operating_System
.	O
</s>
<s>
The	O
IIx	O
was	O
the	O
second	O
of	O
three	O
Macintosh	B-Device
models	O
to	O
use	O
this	O
case	O
allowing	O
dual	O
floppy	B-Device
drives	I-Device
and	O
6	O
NuBus	B-Device
slots	O
;	O
the	O
last	O
model	O
was	O
the	O
Macintosh	B-Device
IIfx	I-Device
.	O
</s>
<s>
Apple	O
's	O
nomenclature	O
of	O
the	O
time	O
used	O
the	O
"	O
x	O
"	O
to	O
indicate	O
the	O
presence	O
of	O
the	O
68030	B-Device
CPU	O
as	O
used	O
in	O
the	O
Macintosh	B-Device
IIcx	I-Device
and	O
IIvx	B-Device
.	O
</s>
