<s>
The	B-Device
Automatic	I-Device
Proofreader	I-Device
is	O
a	O
series	O
of	O
checksum	B-Algorithm
utilities	O
published	O
by	O
COMPUTE	O
!	O
</s>
<s>
These	O
programs	O
allow	O
home	O
computer	O
users	O
to	O
detect	O
errors	O
when	O
entering	O
BASIC	B-Language
type-in	O
programs	O
.	O
</s>
<s>
They	O
display	O
a	O
checksum	B-Algorithm
for	O
each	O
line	O
which	O
can	O
be	O
compared	O
against	O
the	O
one	O
printed	O
in	O
the	O
magazine	O
;	O
if	O
they	O
are	O
the	O
same	O
then	O
the	O
line	O
was	O
typed	O
correctly	O
.	O
</s>
<s>
Initially	O
published	O
for	O
use	O
with	O
the	O
Commodore	O
64	O
and	O
VIC-20	B-Device
in	O
1983	O
.	O
</s>
<s>
The	B-Device
Automatic	I-Device
Proofreader	I-Device
was	O
later	O
made	O
available	O
for	O
the	O
Atari	B-Device
8-bit	I-Device
family	I-Device
,	O
Apple	B-Device
II	I-Device
,	O
IBM	B-Device
PC	I-Device
,	O
and	O
IBM	B-Device
PCjr	I-Device
.	O
</s>
<s>
The	B-Device
Automatic	I-Device
Proofreader	I-Device
was	O
first	O
introduced	O
in	O
October	O
1983	O
for	O
the	O
Commodore	O
64	O
and	O
VIC-20	B-Device
.	O
</s>
<s>
This	O
version	O
of	O
the	O
Proofreader	O
would	O
display	O
a	O
byte-sized	O
numeric	O
value	O
at	O
the	O
top	O
left	O
corner	O
of	O
the	O
screen	O
whenever	O
a	O
program	O
line	O
was	O
entered	O
.	O
</s>
<s>
It	O
was	O
loaded	O
into	O
the	O
cassette	O
buffer	O
(	O
memory	O
area	O
)	O
,	O
which	O
was	O
overwritten	O
whenever	O
a	O
program	O
was	O
loaded	O
or	O
saved	O
using	O
the	O
Datassette	B-Device
.	O
</s>
<s>
Also	O
,	O
the	O
checksum	B-Algorithm
method	O
used	O
was	O
relatively	O
rudimentary	O
,	O
and	O
did	O
not	O
catch	O
transposition	O
errors	O
,	O
nor	O
did	O
it	O
take	O
whitespace	O
into	O
account	O
.	O
</s>
<s>
This	O
version	O
used	O
a	O
more	O
sophisticated	O
checksum	B-Algorithm
algorithm	O
that	O
could	O
catch	O
transposition	O
errors	O
.	O
</s>
<s>
Also	O
,	O
the	O
decimal	O
display	O
of	O
the	O
checksum	B-Algorithm
was	O
replaced	O
by	O
two	O
letters	O
.	O
</s>
<s>
The	O
New	O
Automatic	O
Proofreader	O
was	O
designed	O
to	O
run	O
on	O
any	O
Commodore	O
8-bit	O
home	O
computer	O
(	O
including	O
the	O
C16/Plus/4	O
and	O
C128	B-Device
)	O
,	O
automatically	O
relocating	O
itself	O
to	O
the	O
bottom	O
of	O
BASIC	B-Language
RAM	B-Architecture
and	O
moving	O
pointers	O
to	O
hide	O
its	O
presence	O
.	O
</s>
