<s>
Dual	B-Device
format	I-Device
is	O
a	O
technique	O
used	O
to	O
allow	O
software	O
for	O
two	O
systems	O
which	O
would	O
normally	O
require	O
different	O
disk	B-Application
formats	I-Application
to	O
be	O
recorded	O
on	O
the	O
same	O
floppy	B-Device
disk	I-Device
.	O
</s>
<s>
In	O
the	O
late	O
1980s	O
,	O
the	O
term	O
was	O
used	O
to	O
refer	O
to	O
disks	O
that	O
could	O
be	O
used	O
to	O
boot	O
either	O
an	O
Amiga	B-Device
or	O
Atari	B-Device
ST	I-Device
computer	O
.	O
</s>
<s>
The	O
layout	O
of	O
the	O
first	O
track	O
of	O
the	O
disk	O
was	O
specially	O
laid	O
out	O
to	O
contain	O
an	O
Amiga	B-Device
and	O
an	O
Atari	B-Device
ST	I-Device
boot	B-Device
sector	I-Device
at	O
the	O
same	O
time	O
by	O
fooling	O
the	O
operating	O
system	O
to	O
think	O
that	O
the	O
track	O
resolved	O
into	O
the	O
format	O
it	O
expected	O
.	O
</s>
<s>
The	O
technique	O
was	O
used	O
for	O
some	O
commercially	O
available	O
games	O
,	O
and	O
also	O
for	O
the	O
disks	O
covermounted	O
on	O
ST/Amiga	O
Format	O
magazine	O
.	O
</s>
<s>
Other	O
games	O
came	O
on	O
Amiga	B-Device
and	O
PC	O
dual-format	O
disks	O
,	O
or	O
even	O
"	O
tri-format	O
"	O
disks	O
,	O
which	O
contained	O
the	O
Amiga	B-Device
,	O
Atari	B-Device
ST	I-Device
and	O
PC	O
versions	O
of	O
the	O
game	O
.	O
</s>
<s>
Later	O
,	O
the	O
term	O
was	O
used	O
for	O
disks	O
containing	O
both	O
Windows	B-Application
and	O
Macintosh	B-Device
versions	O
.	O
</s>
