<s>
is	O
an	O
error	B-Error_Name
message	I-Error_Name
found	O
in	O
DOS	B-Device
operating	B-General_Concept
systems	I-General_Concept
,	O
which	O
prompts	O
the	O
end-user	O
for	O
a	O
course	O
of	O
action	O
to	O
follow	O
.	O
</s>
<s>
Although	O
welcomed	O
by	O
some	O
,	O
the	O
message	O
also	O
has	O
been	O
cited	O
as	O
an	O
example	O
of	O
poor	O
usability	B-General_Concept
in	O
computer	O
user	B-Application
interfaces	I-Application
.	O
</s>
<s>
In	O
CP/M	B-Application
,	O
attempting	O
to	O
read	O
a	O
floppy	B-Device
disk	I-Device
drive	I-Device
with	O
the	O
door	O
open	O
would	O
hang	O
until	O
a	O
disk	O
was	O
inserted	O
and	O
the	O
disk	O
drive	O
door	O
was	O
closed	O
(	O
very	O
early	O
disk	O
hardware	O
did	O
not	O
send	O
any	O
kind	O
of	O
signal	O
until	O
a	O
disk	O
was	O
spinning	O
,	O
and	O
a	O
timeout	O
to	O
detect	O
the	O
lack	O
of	O
signal	O
required	O
too	O
much	O
code	O
on	O
these	O
tiny	O
systems	O
)	O
.	O
</s>
<s>
Many	O
users	O
of	O
CP/M	B-Application
became	O
accustomed	O
to	O
this	O
as	O
a	O
method	O
of	O
managing	O
multiple	O
disks	O
,	O
by	O
opening	O
the	O
disk	O
drive	O
to	O
stop	O
a	O
program	O
from	O
reading	O
or	O
writing	O
a	O
file	O
until	O
the	O
correct	O
disk	O
could	O
be	O
inserted	O
.	O
</s>
<s>
A	O
primary	O
design	O
consideration	O
for	O
PC	O
DOS	B-Device
was	O
that	O
software	O
written	O
for	O
CP/M	B-Application
be	O
portable	O
to	O
DOS	B-Device
without	O
changes	O
.	O
</s>
<s>
Even	O
the	O
first	O
IBM	B-Device
PC	I-Device
had	O
hardware	O
that	O
told	O
the	O
operating	B-General_Concept
system	I-General_Concept
that	O
the	O
disk	O
drive	O
door	O
was	O
open	O
,	O
but	O
returning	O
an	O
error	O
to	O
software	O
trying	O
to	O
read	O
the	O
disk	O
would	O
break	O
the	O
ability	O
to	O
manage	O
disks	O
this	O
way	O
without	O
such	O
changes	O
.	O
</s>
<s>
A	O
missing	O
disk	O
(	O
or	O
disk	O
drive	O
door	O
opened	O
)	O
was	O
defined	O
by	O
DOS	B-Device
as	O
a	O
"	O
critical	O
error	O
"	O
and	O
would	O
call	O
the	O
"	O
critical	O
error	O
handler	O
"	O
.	O
</s>
<s>
The	O
default	O
"	O
critical	O
error	O
handler	O
"	O
was	O
part	O
of	O
COMMAND.COM	B-Operating_System
and	O
printed	O
the	O
"	O
Abort	O
,	O
Retry	O
,	O
...	O
"	O
prompt	O
,	O
then	O
waited	O
for	O
user	O
input	O
.	O
</s>
<s>
This	O
could	O
be	O
used	O
for	O
disk	O
read	O
errors	O
,	O
and	O
DOS	B-Device
would	O
return	O
whatever	O
data	O
was	O
in	O
the	O
read	O
buffer	O
(	O
which	O
might	O
contain	O
some	O
of	O
the	O
correct	O
data	O
)	O
.	O
</s>
<s>
Fail	O
(	O
F	O
)	O
:	O
Starting	O
with	O
MS-DOS/PCDOS	O
3.3	O
,	O
"	O
Fail	O
"	O
returned	O
an	O
error	O
code	O
to	O
the	O
program	O
,	O
similar	O
to	O
a	O
"	O
file	B-Error_Name
not	I-Error_Name
found	I-Error_Name
"	O
error	O
.	O
</s>
<s>
Some	O
programs	O
faked	O
the	O
missing	O
"	O
Fail	O
"	O
response	O
in	O
DOS	B-Device
2.0	O
by	O
jumping	O
back	O
to	O
the	O
calling	O
program	O
,	O
skipping	O
the	O
return	O
stack	O
in	O
DOS	B-Device
.	O
</s>
<s>
This	O
was	O
a	O
risky	O
hack	O
as	O
it	O
relied	O
on	O
the	O
stack	O
layout	O
and	O
skipped	O
cleanup	O
operations	O
in	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
error	B-Error_Name
message	I-Error_Name
has	O
been	O
described	O
as	O
being	O
an	O
example	O
of	O
poor	O
user	B-Application
interface	I-Application
design	O
.	O
</s>
<s>
MS-DOS	B-Application
6.22	O
contained	O
a	O
singular	O
case	O
where	O
the	O
only	O
option	O
was	O
"	O
(	O
R	O
)	O
Retry	O
"	O
:	O
when	O
flushing	O
the	O
hard	O
disk	O
write-behind	O
cache	O
could	O
not	O
be	O
completed	O
.	O
</s>
<s>
DOS	B-Device
3.3	O
COMMAND.COM	B-Operating_System
provided	O
the	O
startup	O
option	O
/F	O
to	O
force	O
the	O
default	O
critical	O
error	O
handler	O
to	O
return	O
"	O
Fail	O
"	O
on	O
all	O
errors	O
.	O
</s>
<s>
Starting	O
with	O
version	O
4.0	O
,	O
the	O
alternative	O
command	O
line	O
processors	O
4DOS	B-Application
and	O
NDOS	B-Application
supported	O
/F	O
and	O
the	O
corresponding	O
CritFail	O
=	O
Yes	O
directive	O
in	O
4DOS.INI/NDOS.INI	O
as	O
well	O
.	O
</s>
<s>
The	O
option	O
was	O
also	O
supported	O
by	O
the	O
COMMAND.COM	B-Operating_System
of	O
PTS-DOS	O
6.51	O
and	O
S/DOS	O
1.0	O
,	O
as	O
well	O
as	O
by	O
DR-DOS	O
7.02	O
and	O
higher	O
.	O
</s>
<s>
In	O
OpenDOS	O
7.01	O
,	O
COMMAND.COM	B-Operating_System
provides	O
a	O
similar	O
feature	O
with	O
/N	O
(	O
described	O
as	O
"	O
do	O
not	O
install	O
a	O
critical	O
error	O
handler	O
"	O
)	O
which	O
is	O
still	O
supported	O
in	O
newer	O
versions	O
.	O
</s>
<s>
Most	O
other	O
operating	B-General_Concept
systems	I-General_Concept
,	O
such	O
as	O
Linux	O
,	O
always	O
act	O
like	O
"	O
Fail	O
"	O
in	O
all	O
cases	O
.	O
</s>
<s>
Windows	O
can	O
still	O
generate	O
a	O
similar	O
prompt	O
,	O
although	O
in	O
a	O
dialog	O
box	O
and	O
with	O
a	O
more	O
comprehensive	O
error	B-Error_Name
message	I-Error_Name
.	O
</s>
<s>
However	O
for	O
mundane	O
actions	O
similar	O
to	O
what	O
triggered	O
the	O
prompt	O
in	O
DOS	B-Device
,	O
such	O
as	O
attempting	O
to	O
read	O
"	O
E	O
:	O
"	O
when	O
there	O
is	O
no	O
disk	O
in	O
the	O
CD	O
drive	O
,	O
Windows	O
produces	O
an	O
immediate	O
"	O
Fail	O
"	O
.	O
</s>
<s>
In	O
the	O
1999	O
video	O
game	O
Sid	B-Application
Meier	I-Application
's	I-Application
Alpha	I-Application
Centauri	I-Application
"	O
Abort	O
,	O
Retry	O
,	O
Fail	O
?	O
"	O
</s>
<s>
was	O
graffiti	B-Application
next	O
to	O
the	O
door	O
of	O
the	O
"	O
Edit	O
Universe	O
project	O
,	O
"	O
implied	O
to	O
be	O
a	O
research	O
and	O
development	O
undertaking	O
with	O
an	O
ominous	O
potential	O
.	O
</s>
<s>
The	O
phrase	O
is	O
introduced	O
as	O
an	O
audio	O
quote	O
when	O
the	O
player	O
achieves	O
the	O
technological	O
advance	O
of	O
"	O
Nanomatter	O
Editation	O
,	O
"	O
and	O
ends	O
with	O
the	O
warning	O
,	O
"	O
if	O
...	O
you	O
see	O
this	O
message	O
,	O
always	O
choose	O
'	O
Retry	O
 '	O
.	O
"	O
</s>
