<s>
The	O
DISCiPLE	B-Device
is	O
a	O
floppy	B-Architecture
disk	I-Architecture
interface	I-Architecture
for	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
home	O
computer	O
.	O
</s>
<s>
Like	O
Sinclair	O
's	O
own	O
ZX	B-Device
Interface	I-Device
1	I-Device
,	O
the	O
DISCiPLE	B-Device
was	O
a	O
wedge-shaped	O
unit	O
fitting	O
underneath	O
the	O
Spectrum	O
.	O
</s>
<s>
It	O
was	O
designed	O
as	O
a	O
super-interface	O
,	O
providing	O
all	O
the	O
facilities	O
a	O
Spectrum	O
owner	O
could	O
need	O
.	O
</s>
<s>
In	O
addition	O
to	O
floppy-disk	O
,	O
parallel	B-Device
port	I-Device
printer	O
interface	B-Protocol
and	O
a	O
"	O
magic	O
button	O
"	O
(	O
see	O
Non-maskable	B-General_Concept
interrupt	I-General_Concept
)	O
,	O
it	O
also	O
offered	O
twin	O
joystick	B-Device
ports	O
,	O
Sinclair	O
ZX	O
Net-compatible	O
network	O
ports	O
and	O
an	O
inhibit	O
button	O
for	O
disabling	O
the	O
device	O
.	O
</s>
<s>
At	O
the	O
rear	O
of	O
the	O
unit	O
was	O
a	O
pass-through	O
port	O
for	O
connecting	O
further	O
devices	O
,	O
although	O
the	O
complexity	O
of	O
the	O
DISCiPLE	B-Device
meant	O
that	O
many	O
would	O
not	O
work	O
,	O
or	O
only	O
if	O
the	O
DISCiPLE	B-Device
was	O
"	O
turned	O
off	O
"	O
using	O
the	O
inhibit	O
button	O
.	O
</s>
<s>
The	O
DISCiPLE	B-Device
was	O
a	O
considerable	O
success	O
but	O
its	O
sophistication	O
(	O
the	O
device	O
included	O
8kB	O
of	O
ROM	B-Device
)	O
meant	O
that	O
it	O
was	O
expensive	O
and	O
the	O
plastic	O
casing	O
,	O
located	O
beneath	O
the	O
computer	O
itself	O
,	O
was	O
sometimes	O
prone	O
to	O
overheating	O
.	O
</s>
<s>
These	O
factors	O
led	O
to	O
the	O
development	O
of	O
MGT	O
's	O
later	O
+D	B-Device
interface	B-Protocol
.	O
</s>
<s>
The	O
DISCiPLE	B-Device
's	O
DOS	B-Operating_System
was	O
named	O
GDOS	O
.	O
</s>
<s>
MGT	O
's	O
later	O
DOSs	O
(	O
G+DOS	O
for	O
the	O
+D	B-Device
,	O
and	O
SAM	O
DOS	B-Operating_System
for	O
the	O
SAM	B-Device
Coupé	I-Device
)	O
were	O
backwards-compatible	O
with	O
GDOS	O
.	O
</s>
<s>
In	O
later	O
years	O
a	O
complete	O
new	O
system	O
called	O
UNI-DOS	O
was	O
developed	O
by	O
SD	O
Software	O
for	O
the	O
DISCiPLE	B-Device
and	O
+D	B-Device
interfaces	O
.	O
</s>
<s>
In	O
October	O
1993	O
"	O
The	O
Complete	O
DISCiPLE	B-Device
Disassembly	O
"	O
was	O
published	O
in	O
book	O
form	O
,	O
documenting	O
the	O
"	O
GDOS	O
system	O
3d	O
"	O
version	O
.	O
</s>
<s>
The	O
popularity	O
of	O
the	O
DISCiPLE	B-Device
led	O
to	O
the	O
formation	O
of	O
a	O
user	O
group	O
and	O
magazine	O
,	O
INDUG	O
,	O
which	O
later	O
became	O
Format	B-Device
Publications	I-Device
.	O
</s>
<s>
Usergroups	O
like	O
INDUG/Format	O
in	O
the	O
UK	O
or	O
DISCiPLE-Nieuwsbrief	O
in	O
the	O
Netherlands	O
produced	O
enhancements	O
such	O
as	O
extended	O
printer	O
support	O
.	O
</s>
