<s>
QDOS	O
is	O
the	O
multitasking	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
found	O
on	O
the	O
Sinclair	B-Device
QL	I-Device
personal	B-Device
computer	I-Device
and	O
its	O
clones	O
.	O
</s>
<s>
It	O
was	O
designed	O
by	O
Tony	O
Tebby	O
whilst	O
working	O
at	O
Sinclair	O
Research	O
,	O
as	O
an	O
in-house	O
alternative	O
to	O
68K/OS	B-Operating_System
,	O
which	O
was	O
later	O
cancelled	O
by	O
Sinclair	O
,	O
but	O
released	O
by	O
original	O
authors	O
GST	O
Computer	O
Systems	O
.	O
</s>
<s>
QDOS	O
was	O
implemented	O
in	O
Motorola	B-Device
68000	I-Device
assembly	B-Language
language	I-Language
,	O
and	O
on	O
the	O
QL	O
,	O
resided	O
in	O
48KB	O
of	O
ROM	B-Device
,	O
consisting	O
of	O
either	O
three	O
16KB	O
EPROM	O
chips	O
or	O
one	O
32KB	O
and	O
one	O
16KB	O
ROM	B-Device
chip	I-Device
.	O
</s>
<s>
These	O
ROMs	O
also	O
held	O
the	O
SuperBASIC	B-Language
interpreter	O
,	O
an	O
advanced	O
variant	O
of	O
BASIC	O
programming	O
language	O
with	O
structured	O
programming	O
additions	O
.	O
</s>
<s>
Facilities	O
provided	O
by	O
QDOS	O
included	O
management	O
of	O
processes	B-Operating_System
(	O
or	O
"	O
jobs	O
"	O
in	O
QDOS	O
terminology	O
)	O
,	O
memory	O
allocation	O
,	O
and	O
an	O
extensible	O
"	O
redirectable	O
I/O	O
system	O
"	O
,	O
providing	O
a	O
generic	O
framework	O
for	O
filesystems	B-Application
and	O
device	B-Application
drivers	I-Application
.	O
</s>
<s>
This	O
,	O
and	O
several	O
other	O
features	O
,	O
were	O
never	O
fully	O
implemented	O
in	O
the	O
released	O
versions	O
of	O
QDOS	O
,	O
but	O
were	O
improved	O
in	O
later	O
extensions	O
to	O
the	O
operating	B-General_Concept
system	I-General_Concept
produced	O
by	O
Tebby	O
's	O
own	O
company	O
,	O
QJUMP	O
.	O
</s>
<s>
Rewritten	O
,	O
enhanced	O
versions	O
of	O
QDOS	O
were	O
also	O
developed	O
,	O
including	O
Laurence	O
Reeves	O
 '	O
Minerva	B-Application
and	O
Tebby	O
's	O
SMS2	O
and	O
SMSQ/E	B-Operating_System
.	O
</s>
<s>
However	O
,	O
the	O
QL	O
firmware	O
ROMs	O
as	O
a	O
whole	O
(	O
including	O
SuperBASIC	B-Language
)	O
were	O
given	O
two	O
-	O
or	O
three-letter	O
alphabetic	O
identifiers	O
(	O
returned	O
by	O
the	O
SuperBASIC	B-Language
function	O
VER$	O
)	O
.	O
</s>
<s>
This	O
was	O
faster	O
and	O
had	O
improved	O
Microdrive	B-Device
support	O
.	O
</s>
<s>
1.02	O
:	O
corresponded	O
to	O
the	O
AH	O
ROM	B-Device
version	O
released	O
in	O
June	O
1984	O
.	O
</s>
<s>
This	O
fixed	O
many	O
bugs	O
and	O
was	O
the	O
first	O
ROM	B-Device
version	O
to	O
be	O
produced	O
in	O
quantity	O
.	O
</s>
<s>
1.03	O
:	O
included	O
in	O
ROM	B-Device
versions	O
JM	O
and	O
TB	O
;	O
a	O
minor	O
bug-fix	O
release	O
issued	O
in	O
late	O
1984	O
.	O
</s>
<s>
1.13	O
:	O
corresponding	O
to	O
the	O
MGx	O
series	O
of	O
ROM	B-Device
versions	O
for	O
European	O
export	O
markets	O
.	O
</s>
<s>
in	O
the	O
version	O
number	O
being	O
replaced	O
by	O
the	O
ROM	B-Device
version	O
suffix	O
letter	O
used	O
to	O
identify	O
the	O
territory	O
,	O
e.g.	O
</s>
<s>
All	O
MG	O
firmware	O
versions	O
shared	O
the	O
same	O
bottom	O
32KB	O
ROM	B-Device
chip	I-Device
.	O
</s>
<s>
Qdos	O
1.13	O
was	O
also	O
reported	O
to	O
be	O
included	O
in	O
a	O
Greek	O
localised	O
ROM	B-Device
version	O
,	O
known	O
as	O
ΣFP	O
(	O
marked	O
on	O
the	O
ROMs	O
as	O
EFP	O
)	O
.	O
</s>
