<s>
Apple	B-Operating_System
Pascal	I-Operating_System
is	O
an	O
implementation	O
of	O
Pascal	B-Application
for	O
the	O
Apple	B-Device
II	I-Device
and	O
Apple	B-Device
III	I-Device
computer	O
series	O
.	O
</s>
<s>
It	O
is	O
based	O
on	O
UCSD	B-Language
Pascal	I-Language
.	O
</s>
<s>
Just	O
like	O
other	O
UCSD	B-Language
Pascal	I-Language
implementations	O
,	O
it	O
ran	O
on	O
its	O
own	O
operating	O
system	O
(	O
Apple	B-Operating_System
Pascal	I-Operating_System
Operating	O
System	O
,	O
a	O
derivative	O
of	O
UCSD	B-Language
p-System	I-Language
with	O
graphical	O
extensions	O
)	O
.	O
</s>
<s>
Originally	O
released	O
for	O
the	O
Apple	B-Device
II	I-Device
in	O
August	O
1979	O
,	O
just	O
after	O
Apple	B-Operating_System
DOS	I-Operating_System
3.2	O
,	O
Apple	B-Operating_System
Pascal	I-Operating_System
pioneered	O
a	O
number	O
of	O
features	O
that	O
would	O
later	O
be	O
incorporated	O
into	O
DOS	O
3.3	O
,	O
as	O
well	O
as	O
others	O
that	O
would	O
not	O
be	O
seen	O
again	O
until	O
the	O
introduction	O
of	O
ProDOS	B-Operating_System
.	O
</s>
<s>
The	O
Apple	B-Operating_System
Pascal	I-Operating_System
software	O
package	O
also	O
included	O
disk	O
maintenance	O
utilities	O
,	O
and	O
an	O
assembler	O
meant	O
to	O
complement	O
Apple	O
's	O
built-in	O
"	O
monitor	O
"	O
assembler	O
.	O
</s>
<s>
A	O
FORTRAN	B-Application
compiler	O
(	O
written	O
by	O
Silicon	O
Valley	O
Software	O
,	O
Sunnyvale	O
California	O
)	O
compiling	O
to	O
the	O
same	O
p-code	O
as	O
Pascal	B-Application
was	O
also	O
available	O
.	O
</s>
<s>
Apple	B-Operating_System
Pascal	I-Operating_System
Operating	O
System	O
introduced	O
a	O
new	O
disk	O
format	O
.	O
</s>
<s>
Instead	O
of	O
dividing	O
the	O
disk	O
into	O
256-byte	O
sectors	O
as	O
in	O
DOS	O
3.2	O
,	O
Apple	B-Operating_System
Pascal	I-Operating_System
divides	O
it	O
into	O
"	O
blocks	O
"	O
of	O
512	O
bytes	O
each	O
.	O
</s>
<s>
The	O
p-System	B-Language
also	O
introduced	O
a	O
different	O
method	O
for	O
saving	O
and	O
retrieving	O
files	O
.	O
</s>
<s>
Under	O
Apple	B-Operating_System
DOS	I-Operating_System
,	O
files	O
were	O
saved	O
to	O
any	O
available	O
sector	O
that	O
the	O
OS	O
could	O
find	O
,	O
regardless	O
of	O
location	O
.	O
</s>
<s>
Over	O
time	O
,	O
this	O
could	O
lead	O
to	O
file	B-Application
system	I-Application
fragmentation	I-Application
,	O
slowing	O
access	O
to	O
the	O
disk	O
.	O
</s>
<s>
Apple	B-Operating_System
Pascal	I-Operating_System
attempted	O
to	O
rectify	O
this	O
by	O
saving	O
only	O
to	O
consecutive	O
blocks	O
on	O
the	O
disk	O
.	O
</s>
<s>
Limitations	O
of	O
the	O
p-System	B-Language
included	O
new	O
restrictions	O
on	O
the	O
naming	O
of	O
files	O
.	O
</s>
<s>
The	O
biggest	O
problem	O
with	O
the	O
Apple	B-Operating_System
Pascal	I-Operating_System
system	O
was	O
that	O
it	O
was	O
too	O
big	O
to	O
fit	O
on	O
one	O
floppy	B-Device
disk	I-Device
.	O
</s>
<s>
This	O
meant	O
that	O
on	O
a	O
system	O
with	O
only	O
one	O
floppy	B-Device
disk	I-Device
drive	I-Device
,	O
frequent	O
disk	O
swapping	O
was	O
needed	O
.	O
</s>
