<s>
The	O
Z-80	B-Device
SoftCard	I-Device
is	O
a	O
plug-in	O
Apple	B-Device
II	I-Device
processor	I-Device
card	I-Device
developed	O
by	O
Microsoft	O
to	O
turn	O
the	O
computer	O
into	O
a	O
CP/M	B-Application
system	O
based	O
upon	O
the	O
Zilog	B-General_Concept
Z80	I-General_Concept
central	O
processing	O
unit	O
(	O
CPU	O
)	O
.	O
</s>
<s>
Becoming	O
the	O
most	O
popular	O
CP/M	B-Application
platform	O
and	O
Microsoft	O
's	O
top	O
revenue	O
source	O
for	O
1980	O
,	O
it	O
was	O
eventually	O
renamed	O
the	O
Microsoft	B-Device
SoftCard	I-Device
,	O
and	O
was	O
succeeded	O
by	O
Microsoft	O
's	O
Premium	B-Device
Softcard	I-Device
IIe	I-Device
for	O
the	O
Apple	B-Device
IIe	I-Device
.	O
</s>
<s>
Introduced	O
in	O
1980	O
as	O
Microsoft	O
's	O
first	O
hardware	O
product	O
,	O
and	O
bundled	O
with	O
the	O
Microsoft	B-Language
BASIC	I-Language
programming	O
language	O
,	O
the	O
Z-80	B-Device
SoftCard	I-Device
is	O
an	O
Apple	B-Device
II	I-Device
processor	I-Device
card	I-Device
that	O
enables	O
the	O
Apple	B-Device
II	I-Device
to	O
run	O
CP/M	B-Application
,	O
an	O
operating	O
system	O
from	O
Digital	O
Research	O
.	O
</s>
<s>
This	O
gives	O
Apple	B-Device
II	I-Device
users	O
access	O
to	O
many	O
more	O
business	O
applications	O
,	O
including	O
compilers	B-Language
and	O
interpreters	B-Application
for	O
several	O
high-level	B-Language
languages	I-Language
.	O
</s>
<s>
CP/M	B-Application
,	O
one	O
of	O
the	O
earliest	O
cross-platform	O
operating	O
systems	O
,	O
is	O
easily	O
adaptable	O
to	O
a	O
wide	O
range	O
of	O
auxiliary	O
chips	O
and	O
peripheral	O
hardware	O
,	O
but	O
it	O
requires	O
an	O
Intel	O
8080-compatible	O
CPU	O
,	O
which	O
the	O
Zilog	B-General_Concept
Z80	I-General_Concept
is	O
,	O
but	O
which	O
the	O
Apple	O
's	O
CPU	O
,	O
the	O
MOS	B-General_Concept
Technology	I-General_Concept
6502	I-General_Concept
,	O
is	O
not	O
.	O
</s>
<s>
The	O
SoftCard	B-Device
has	O
a	O
Zilog	B-General_Concept
Z80	I-General_Concept
CPU	O
plus	O
some	O
74LS00	O
series	O
TTL	B-General_Concept
chips	O
to	O
adapt	O
that	O
processor	O
's	O
bus	B-General_Concept
to	O
the	O
Apple	O
bus	B-General_Concept
.	O
</s>
<s>
As	O
CP/M	B-Application
requires	O
contiguous	O
memory	O
from	O
address	O
zero	O
,	O
which	O
the	O
Apple	B-Device
II	I-Device
does	O
n't	O
have	O
;	O
addresses	O
are	O
translated	O
in	O
order	O
to	O
move	O
non-RAM	O
areas	O
to	O
the	O
top	O
of	O
memory	O
.	O
</s>
<s>
The	O
SoftCard	B-Device
was	O
Paul	O
Allen	O
's	O
idea	O
.	O
</s>
<s>
Its	O
original	O
purpose	O
was	O
to	O
simplify	O
porting	O
Microsoft	O
's	O
computer-language	O
products	O
to	O
the	O
Apple	B-Device
II	I-Device
.	O
</s>
<s>
The	O
SoftCard	B-Device
was	O
developed	O
by	O
Tim	O
Paterson	O
of	O
Seattle	O
Computer	O
Products	O
(	O
SCP	O
)	O
.	O
</s>
<s>
Microsoft	O
also	O
released	O
a	O
version	O
for	O
the	O
Apple	B-Device
IIe	I-Device
,	O
the	O
Premium	B-Device
Softcard	I-Device
IIe	I-Device
.	O
</s>
<s>
The	O
card	O
has	O
functionality	O
equivalent	O
to	O
the	O
Extended	B-Device
80-Column	I-Device
Text	I-Device
Card	I-Device
,	O
including	O
its	O
64kB	O
RAM	O
,	O
so	O
would	O
save	O
money	O
for	O
users	O
who	O
wanted	O
CP/M	B-Application
capability	O
,	O
additional	O
memory	O
,	O
and	O
80-column	O
text	O
.	O
</s>
<s>
The	O
SoftCard	B-Device
's	O
immediate	O
success	O
surprised	O
Microsoft	O
.	O
</s>
<s>
The	O
SoftCard	B-Device
became	O
the	O
company	O
's	O
largest	O
revenue	O
source	O
in	O
1980	O
,	O
selling	O
5,000	O
units	O
in	O
three	O
months	O
at	O
$349	O
each	O
,	O
with	O
high	O
sales	O
continued	O
for	O
several	O
years	O
.	O
</s>
<s>
The	O
SoftCard	B-Device
was	O
the	O
single	O
most-popular	O
platform	O
to	O
run	O
CP/M	B-Application
,	O
and	O
Z-80	B-General_Concept
cards	O
became	O
very	O
popular	O
Apple	B-Device
II	I-Device
peripherals	O
.	O
</s>
<s>
By	O
1981	O
Microsoft	O
,	O
Lifeboat	O
Associates	O
,	O
and	O
Peachtree	B-Application
Software	I-Application
published	O
their	O
CP/M	B-Application
software	O
on	O
Apple-format	O
disks	O
.	O
</s>
<s>
witnessed	O
the	O
SoftCard	B-Device
's	O
debut	O
in	O
March	O
1980	O
at	O
the	O
West	O
Coast	O
Computer	O
Faire	O
,	O
calling	O
it	O
"	O
an	O
Apple	O
breakthru	O
"	O
.	O
</s>
<s>
InfoWorld	O
in	O
1981	O
called	O
the	O
SoftCard	B-Device
"	O
a	O
fascinating	O
piece	O
of	O
hardware	O
"	O
.	O
</s>
<s>
While	O
criticizing	O
the	O
"	O
computerese	O
"	O
of	O
the	O
CP/M	B-Application
documentation	O
,	O
the	O
magazine	O
wrote	O
"	O
if	O
you	O
need	O
a	O
lightweight	O
,	O
portable	O
Z80	B-General_Concept
computer	O
,	O
the	O
Apple/SoftCard	O
combination	O
is	O
a	O
perfect	O
pair.	O
"	O
</s>
<s>
BYTE	O
wrote	O
,	O
"	O
Because	O
of	O
the	O
flexibility	O
that	O
it	O
offers	O
Apple	O
users	O
,	O
I	O
consider	O
the	O
Softcard	B-Device
an	O
excellent	O
buy	O
..	O
</s>
<s>
InfoWorld	O
in	O
1984	O
also	O
favorably	O
reviewed	O
the	O
SoftCard	B-Device
IIe	B-Device
,	O
approving	O
of	O
its	O
ability	O
to	O
also	O
replace	O
the	O
Extended	B-Device
80-Column	I-Device
Text	I-Device
Card	I-Device
.	O
</s>
<s>
The	O
magazine	O
concluded	O
that	O
it	O
"	O
is	O
a	O
good	O
system	O
among	O
several	O
good	O
systems	O
on	O
the	O
market	O
"	O
,	O
especially	O
for	O
those	O
who	O
wanted	O
to	O
run	O
Microsoft	B-Language
BASIC	I-Language
or	O
wanted	O
functionality	O
beyond	O
CP/M	B-Application
.	O
</s>
<s>
Following	O
Microsoft	O
's	O
success	O
,	O
several	O
other	O
companies	O
developed	O
Z80	B-General_Concept
cards	O
for	O
the	O
Apple	B-Device
II	I-Device
as	O
well	O
,	O
including	O
Digital	O
Research	O
with	O
and	O
a	O
CP/M	B-Application
card	O
developed	O
by	O
Advanced	O
Logic	O
Systems	O
named	O
"	O
The	O
CP/M	B-Application
Card	O
"	O
(	O
with	O
a	O
6MHz	O
Z80	B-General_Concept
and	O
64kB	O
RAM	O
)	O
and	O
Digital	O
Research	O
's	O
CP/M	B-Application
Gold	O
Card	O
for	O
CP/M	B-Application
Pro	O
3.0	O
(	O
with	O
64	O
or	O
192kB	O
RAM	O
)	O
.	O
</s>
<s>
There	O
were	O
also	O
about	O
a	O
dozen	O
SoftCard	B-Device
clone	O
manufacturers	O
.	O
</s>
