<s>
The	O
CMOS	O
W65C51	O
Asynchronous	B-Architecture
Communications	I-Architecture
Interface	I-Architecture
Adapter	I-Architecture
(	O
ACIA	O
)	O
provides	O
an	O
easily	O
implemented	O
,	O
program	O
controlled	O
interface	O
between	O
microprocessor	O
based	O
systems	O
and	O
serial	O
communication	O
data	O
sets	O
and	O
modems	O
.	O
</s>
<s>
It	O
is	O
produced	O
by	O
Western	O
Design	O
Center	O
(	O
WDC	O
)	O
and	O
is	O
a	O
drop-in	O
replacement	O
for	O
the	O
MOS	B-Architecture
Technology	I-Architecture
6551	I-Architecture
.	O
</s>
<s>
Transmitter	O
and	O
receiver	O
data	O
Registers	O
are	O
used	O
for	O
temporary	O
data	O
storage	O
by	O
the	O
transmit	O
and	O
receiver	O
circuits	O
,	O
each	O
able	O
to	O
hold	O
one	O
byte	B-Application
.	O
</s>
<s>
This	O
feature	O
of	O
the	O
W65C51N	O
works	O
different	O
from	O
earlier	O
6551	B-Architecture
designs.	O
"	O
</s>
