<s>
The	O
Mac286	B-Device
was	O
an	O
Intel	O
80286-based	O
MS-DOS	B-Application
coprocessor	B-General_Concept
expansion	B-Device
card	I-Device
for	O
one	O
of	O
Apple	O
Computer	O
's	O
first	O
expandable	O
Macintosh	B-Device
computers	O
,	O
the	O
1987	O
Macintosh	B-Device
II	I-Device
.	O
</s>
<s>
It	O
was	O
developed	O
by	O
Phoenix	O
Technologies	O
under	O
contract	O
to	O
Apple	O
Computer	O
and	O
sold	O
by	O
AST	O
Research	O
in	O
an	O
effort	O
to	O
close	O
the	O
gap	O
between	O
the	O
Macintosh	B-Device
and	O
IBM	B-Device
PC	I-Device
computing	O
worlds	O
.	O
</s>
<s>
AST	O
also	O
introduced	O
the	O
related	O
Mac86	O
card	O
for	O
the	O
Macintosh	B-Device
SE	I-Device
.	O
</s>
<s>
By	O
1989	O
,	O
AST	O
had	O
left	O
the	O
Apple	O
market	O
and	O
sold	O
the	O
rights	O
and	O
technologies	O
for	O
the	O
Mac286	B-Device
and	O
Mac86	O
cards	O
to	O
Orange	O
Micro	O
.	O
</s>
<s>
Orange	O
Micro	O
would	O
later	O
make	O
a	O
successful	O
line	O
of	O
coprocessor	B-General_Concept
cards	O
based	O
on	O
the	O
80x86	O
processor	O
family	O
,	O
before	O
leaving	O
the	O
coprocessor	B-General_Concept
market	O
to	O
concentrate	O
on	O
USB	B-Protocol
and	O
FireWire	B-Protocol
products	O
.	O
</s>
<s>
In	O
1992	O
,	O
Orange	O
Micro	O
discontinued	O
the	O
Mac286	B-Device
board	O
.	O
</s>
<s>
The	O
Mac86	O
was	O
designed	O
for	O
the	O
Macintosh	B-Device
SE	I-Device
PDS	B-Device
slot	I-Device
,	O
and	O
integrated	O
a	O
10	O
MHz	O
Intel	B-General_Concept
8086	I-General_Concept
CPU	O
.	O
</s>
<s>
The	O
Mac86	O
did	O
not	O
include	O
its	O
own	O
RAM	O
,	O
instead	O
sharing	O
up	O
to	O
640	O
KB	O
of	O
the	O
host	O
Macintosh	B-Device
's	O
RAM	O
.	O
</s>
<s>
There	O
are	O
three	O
distinct	O
versions	O
of	O
the	O
Mac286	B-Device
hardware	O
:	O
</s>
<s>
The	O
original	O
AST	O
version	O
consists	O
of	O
a	O
pair	O
of	O
full-length	O
NuBus	B-Device
cards	O
,	O
joined	O
by	O
two	O
ribbon	O
cables	O
.	O
</s>
<s>
Intel	B-General_Concept
80286	I-General_Concept
processor	O
,	O
operating	O
at	O
8MHz	O
,	O
12MHz	O
or	O
16MHz	O
,	O
depending	O
on	O
version	O
.	O
</s>
<s>
Phoenix	O
Technologies	O
286	B-General_Concept
BIOS	O
v3.00	O
(	O
This	O
is	O
an	O
AT	O
BIOS	O
.	O
)	O
</s>
<s>
NEC	O
765-based	O
floppy	O
controller	O
(	O
NOTE	O
:	O
Unlike	O
most	O
PC	O
floppy	O
controller	O
boards	O
,	O
the	O
circuit	O
in	O
the	O
Mac286	B-Device
allows	O
for	O
Single	O
Density	O
operation	O
.	O
</s>
<s>
The	O
Mac286	B-Device
software	O
provides	O
emulation	O
of	O
the	O
following	O
additional	O
hardware	O
:	O
</s>
