<s>
The	O
BBC	B-Device
Master	I-Device
is	O
a	O
home	O
computer	O
released	O
by	O
Acorn	O
Computers	O
in	O
early	O
1986	O
.	O
</s>
<s>
It	O
was	O
designed	O
and	O
built	O
for	O
the	O
British	O
Broadcasting	O
Corporation	O
(	O
BBC	O
)	O
and	O
was	O
the	O
successor	O
to	O
the	O
BBC	B-Device
Micro	I-Device
Model	I-Device
B	I-Device
.	O
</s>
<s>
The	O
Master	O
series	O
featured	O
several	O
improvements	O
on	O
preceding	O
BBC	B-Device
Micro	I-Device
models	O
.	O
</s>
<s>
The	O
systems	O
had	O
RAM	B-Architecture
as	O
standard	O
,	O
alleviating	O
the	O
shortage	O
of	O
available	O
RAM	B-Architecture
which	O
had	O
amongst	O
other	O
things	O
discouraged	O
use	O
of	O
the	O
best	O
graphics	O
modes	O
in	O
the	O
original	O
design	O
.	O
</s>
<s>
The	O
Master	O
128	O
and	O
its	O
variants	O
had	O
two	O
cartridge	O
slots	O
mounted	O
behind	O
the	O
new	O
numerical	O
keypad	O
,	O
these	O
employing	O
sockets	O
that	O
provided	O
a	O
superset	O
of	O
the	O
Acorn	B-Device
Electron	I-Device
Plus	O
1	O
cartridge	O
interface	O
capabilities	O
,	O
supporting	O
the	O
use	O
of	O
physically	O
compatible	O
Electron	O
cartridges	O
,	O
but	O
also	O
supporting	O
enhanced	O
electrical	O
characteristics	O
for	O
some	O
of	O
the	O
cartridge	O
connector	O
pins	O
.	O
</s>
<s>
Rather	O
than	O
the	O
MOS	B-General_Concept
Technology	I-General_Concept
6502	I-General_Concept
microprocessor	B-General_Concept
used	O
by	O
the	O
Model	B-Device
B	I-Device
it	O
ran	O
on	O
the	O
slightly	O
improved	O
65C12	B-General_Concept
.	O
</s>
<s>
The	O
cost	O
of	O
this	O
CPU	O
compatibility	O
with	O
the	O
Model	B-Device
B	I-Device
was	O
that	O
the	O
address	O
bus	O
was	O
still	O
only	O
16	O
bits	O
,	O
meaning	O
that	O
only	O
could	O
be	O
directly	O
addressed	O
at	B-Operating_System
any	O
one	O
time	O
and	O
the	O
remaining	O
memory	O
had	O
to	O
be	O
paged	O
in	O
as	O
required	O
.	O
</s>
<s>
This	O
paging	O
occurred	O
via	O
three	O
separate	O
pages	O
,	O
each	O
with	O
a	O
codename	O
,	O
following	O
previous	O
BBC	B-Device
Microcomputer	I-Device
architecture	O
traditions	O
:	O
</s>
<s>
However	O
the	O
65SC12	O
's	O
extra	O
instructions	O
allowed	O
a	O
little	O
more	O
to	O
be	O
shoehorned	O
into	O
the	O
OS	B-General_Concept
and	O
BBC	B-Language
BASIC	I-Language
ROMs	O
,	O
limited	O
by	O
the	O
memory	O
architecture	O
to	O
each	O
.	O
</s>
<s>
The	O
improved	O
version	O
of	O
BBC	B-Language
Basic	I-Language
was	O
named	O
Basic4	O
.	O
</s>
<s>
Conversely	O
,	O
although	O
few	O
programs	O
were	O
ever	O
targeted	O
specifically	O
at	B-Operating_System
Master	O
series	O
machines	O
(	O
except	O
the	O
Master	O
512	O
)	O
,	O
many	O
later	O
BBC	O
games	O
(	O
and	O
Master	O
versions	O
of	O
earlier	O
classics	O
such	O
as	O
Elite	B-Application
)	O
included	O
enhanced	O
features	O
which	O
took	O
advantage	O
of	O
the	O
extra	O
memory	O
.	O
</s>
<s>
An	O
upgrade	O
to	O
the	O
Master	O
128	O
operating	B-General_Concept
system	I-General_Concept
ROM	B-Device
was	O
released	O
by	O
Acorn	O
in	O
early	O
1990	O
,	O
providing	O
bug	O
fixes	O
and	O
some	O
performance	O
and	O
functionality	O
enhancements	O
,	O
with	O
the	O
filing	O
systems	O
benefiting	O
in	O
particular	O
.	O
</s>
<s>
An	O
input	O
method	O
was	O
provided	O
to	O
permit	O
the	O
input	O
of	O
"	O
foreign	O
characters	O
"	O
or	O
"	O
top-bit-set	O
characters	O
"	O
-	O
character	O
codes	O
in	O
the	O
range	O
from	O
128	O
to	O
255	O
-	O
from	O
the	O
keyboard	B-Device
,	O
and	O
the	O
View	O
,	O
Viewsheet	B-Language
and	O
Edit	O
applications	O
all	O
saw	O
various	O
levels	O
of	O
enhancement	O
.	O
</s>
<s>
One	O
notable	O
feature	O
was	O
the	O
introduction	O
of	O
"	O
relocatable	O
"	O
language	O
(	O
or	O
application	O
)	O
ROM	B-Device
support	O
,	O
permitting	O
appropriately	O
written	O
ROM-based	O
software	O
to	O
automatically	O
take	O
advantage	O
of	O
a	O
second	O
processor	O
,	O
if	O
fitted	O
.	O
</s>
<s>
Priced	O
at	B-Operating_System
around	O
£45	O
,	O
it	O
was	O
noted	O
that	O
since	O
the	O
copyright	O
message	O
in	O
the	O
ROM	B-Device
was	O
dated	O
1988	O
and	O
the	O
manual	O
dated	O
October	O
1989	O
,	O
such	O
an	O
upgrade	O
might	O
have	O
been	O
more	O
widely	O
adopted	O
by	O
users	O
(	O
and	O
the	O
relocatable	O
ROM	B-Device
feature	O
adopted	O
by	O
software	O
producers	O
)	O
had	O
it	O
been	O
released	O
earlier	O
,	O
with	O
the	O
Master	O
Compact	O
ROM	B-Device
having	O
already	O
benefited	O
from	O
some	O
of	O
the	O
featured	O
improvements	O
.	O
</s>
<s>
The	O
128	O
in	O
the	O
name	O
referred	O
to	O
its	O
128KB	O
of	O
RAM	B-Architecture
,	O
though	O
it	O
also	O
featured	O
128KB	O
ROM	B-Device
.	O
</s>
<s>
This	O
was	O
a	O
Master	O
128	O
with	O
4MHz	O
65C102	B-General_Concept
coprocessor	O
card	O
(	O
which	O
could	O
be	O
either	O
bought	O
with	O
the	O
machine	O
or	O
added	O
to	O
an	O
existing	O
Master	O
128	O
)	O
.	O
</s>
<s>
The	O
Master	O
AIV	O
(	O
Advanced	O
Interactive	O
Videodisc	O
)	O
was	O
essentially	O
a	O
Master	O
Turbo	O
model	O
with	O
a	O
SCSI	B-Architecture
interface	O
and	O
a	O
VFS	O
(	O
Videodisc	O
Filing	O
System	O
)	O
ROM	B-Device
added	O
,	O
and	O
formed	O
the	O
basis	O
of	O
the	O
BBC	B-Device
Domesday	I-Device
System	I-Device
.	O
</s>
<s>
Although	O
normally	O
supplied	O
as	O
part	O
of	O
a	O
Domesday	O
System	O
,	O
with	O
LaserVision	O
player	O
,	O
Domesday	O
videodiscs	O
,	O
monitor	O
and	O
trackerball	B-Device
included	O
,	O
an	O
upgrade	O
kit	O
was	O
also	O
available	O
to	O
turn	O
a	O
normal	O
BBC	B-Device
Master	I-Device
into	O
a	O
Domesday	O
System	O
.	O
</s>
<s>
The	O
ET	O
(	O
Econet	B-Device
Terminal	O
)	O
system	O
was	O
designed	O
for	O
use	O
in	O
a	O
network	O
and	O
as	O
such	O
had	O
no	O
interfaces	O
except	O
RGB	O
and	O
Composite	O
video	O
,	O
plus	O
an	O
Econet	B-Device
interface	O
module	O
and	O
ANFS	O
fitted	O
as	O
standard	O
(	O
it	O
was	O
usually	O
an	O
option	O
)	O
.	O
</s>
<s>
The	O
internal	O
ROM	B-Device
also	O
contained	O
much	O
less	O
software	O
than	O
that	O
of	O
the	O
Master	O
128	O
.	O
</s>
<s>
This	O
system	O
boasted	O
a	O
coprocessor	O
card	O
with	O
a	O
10MHz	O
Intel	B-Device
80186	I-Device
and	O
512KB	O
memory	O
.	O
</s>
<s>
It	O
also	O
had	O
the	O
ability	O
to	O
run	O
DOS	B-Operating_System
Plus	I-Operating_System
and	O
the	O
GEM	B-Application
graphical	B-Application
user	I-Application
interface	I-Application
.	O
</s>
<s>
The	O
coprocessor	O
card	O
was	O
introduced	O
at	B-Operating_System
£499	O
as	O
an	O
upgrade	O
to	O
the	O
Master	O
128	O
,	O
but	O
its	O
price	O
was	O
subsequently	O
reduced	O
to	O
£399	O
.	O
</s>
<s>
The	O
additional	O
memory	O
requirements	O
of	O
DOS	B-Operating_System
Plus	I-Operating_System
,	O
when	O
compared	O
to	O
those	O
of	O
PC	B-Operating_System
DOS	I-Operating_System
,	O
and	O
the	O
requirements	O
of	O
the	O
GEM	B-Application
desktop	I-Application
caused	O
potential	O
problems	O
when	O
running	O
some	O
applications	O
,	O
although	O
memory	O
expansions	O
existed	O
to	O
mitigate	O
such	O
problems	O
.	O
</s>
<s>
System	O
call	O
compatibility	O
was	O
only	O
assured	O
for	O
MS-DOS	O
and	O
PC	B-Operating_System
DOS	I-Operating_System
2.1	O
,	O
but	O
other	O
DOS	O
versions	O
were	O
not	O
supported	O
,	O
and	O
undocumented	O
system	O
call	O
usage	O
(	O
"	O
fairly	O
rare	O
,	O
but	O
does	O
include	O
some	O
Microsoft	O
packages	O
"	O
)	O
could	O
cause	O
applications	O
to	O
run	O
incorrectly	O
.	O
</s>
<s>
Software	O
written	O
for	O
later	O
GEM	B-Application
versions	O
would	O
also	O
not	O
necessarily	O
run	O
correctly	O
.	O
</s>
<s>
A	O
product	O
by	O
Shibumi	O
Software	O
called	O
Problem	O
Solver	O
aimed	O
to	O
address	O
various	O
compatibility	O
issues	O
related	O
to	O
the	O
increased	O
speed	O
of	O
the	O
coprocessor	O
relative	O
to	O
a	O
traditional	O
IBM	O
PC	O
,	O
display	O
and	O
keyboard	B-Device
differences	O
(	O
also	O
supporting	O
the	O
BBC	B-Device
Model	I-Device
B	I-Device
keyboard	B-Device
for	O
users	O
of	O
that	O
machine	O
with	O
the	O
co-processor	O
attached	O
)	O
,	O
the	O
behaviour	O
of	O
"	O
memory	O
resident	O
packages	O
"	O
such	O
as	O
Sidekick	O
,	O
and	O
the	O
behaviour	O
of	O
particular	O
applications	O
.	O
</s>
<s>
The	O
product	O
reportedly	O
allowed	O
well-known	O
programs	O
such	O
as	O
Ashton	O
Tate	O
's	O
dBase	O
III	O
and	O
Borland	O
's	O
Turbo	B-Application
C	I-Application
and	O
Turbo	B-Application
Prolog	I-Application
to	O
work	O
on	O
the	O
coprocessor	O
.	O
</s>
<s>
To	O
remedy	O
compatibility	O
issues	O
caused	O
by	O
a	O
lack	O
of	O
memory	O
,	O
one	O
company	O
,	O
Essential	O
Software	O
,	O
provided	O
an	O
upgrade	O
service	O
augmenting	O
the	O
fitted	O
RAM	B-Architecture
of	O
the	O
Master	O
512	O
upgrade	O
with	O
four	O
1megabit	O
devices	O
providing	O
512KB	O
to	O
yield	O
a	O
total	O
of	O
1MB	O
of	O
RAM	B-Architecture
.	O
</s>
<s>
Priced	O
at	B-Operating_System
£99	O
,	O
and	O
also	O
compatible	O
with	O
Problem	O
Solver	O
,	O
the	O
upgrade	O
overcame	O
the	O
elevated	O
memory	O
requirements	O
of	O
DOS	B-Operating_System
Plus	I-Operating_System
relative	O
to	O
MS-DOS	O
and	O
also	O
allowed	O
the	O
system	O
to	O
meet	O
the	O
requirement	O
of	O
some	O
applications	O
to	O
have	O
640KB	O
of	O
memory	O
available	O
.	O
</s>
<s>
Consequently	O
,	O
GEM	B-Application
3	O
,	O
Ventura	B-Application
Publisher	I-Application
,	O
WordPerfect	B-Application
5.0	O
and	O
dBase	O
IV	O
were	O
all	O
reported	O
as	O
being	O
compatible	O
.	O
</s>
<s>
The	O
company	O
also	O
produced	O
a	O
selection	O
of	O
utilities	O
for	O
the	O
Master	O
512	O
,	O
including	O
the	O
Co-Processor	O
Filing	O
System	O
(	O
CPFS	O
)	O
which	O
allowed	O
the	O
512KB	O
of	O
coprocessor	O
memory	O
to	O
be	O
used	O
as	O
a	O
RAM	B-Architecture
disc	O
by	O
the	O
computer	O
when	O
operating	O
in	O
its	O
"	O
native	O
"	O
BBC	B-Device
Micro	I-Device
mode	O
.	O
</s>
<s>
The	O
price	O
was	O
further	O
reduced	O
to	O
£199	O
plus	O
VAT	O
in	O
early	O
1987	O
,	O
with	O
GEM	B-Application
Desk	O
Top	O
,	O
GEM	B-Application
Write	O
and	O
GEM	B-Application
Paint	O
being	O
provided	O
free	O
with	O
the	O
upgrade	O
,	O
and	O
a	O
"	O
final	O
price	O
cut	O
to	O
£99	O
"	O
was	O
reported	O
in	O
1989	O
,	O
effectively	O
exhausting	O
the	O
remaining	O
stocks	O
.	O
</s>
<s>
Although	O
largely	O
abandoned	O
by	O
Acorn	O
as	O
the	O
company	O
shifted	O
its	O
emphasis	O
to	O
the	O
Archimedes	B-Device
range	O
,	O
one	O
commentator	O
considered	O
it	O
"	O
one	O
of	O
the	O
most	O
exciting	O
products	O
Acorn	O
has	O
ever	O
developed	O
"	O
.	O
</s>
<s>
The	O
Master	O
Scientific	O
was	O
announced	O
at	B-Operating_System
the	O
time	O
of	O
the	O
BBC	B-Device
Master	I-Device
's	O
launch	O
,	O
but	O
was	O
not	O
produced	O
.	O
</s>
<s>
It	O
was	O
to	O
have	O
an	O
8MHz	O
32016	B-Device
coprocessor	O
with	O
32081	O
floating	O
point	O
processor	O
and	O
512KB	O
of	O
RAM	B-Architecture
,	O
running	O
the	O
PANOS	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
This	O
was	O
similar	O
to	O
the	O
previous	O
external	O
32016	B-Device
Second	O
Processor	O
.	O
</s>
<s>
Ultimately	O
,	O
Acorn	O
dropped	O
the	O
Scientific	O
due	O
to	O
unspecified	O
technical	O
problems	O
with	O
the	O
co-processor	O
,	O
also	O
indicating	O
that	O
512KB	O
of	O
RAM	B-Architecture
appeared	O
to	O
be	O
insufficient	O
for	O
the	O
target	O
audience	O
,	O
whose	O
applications	O
tended	O
to	O
need	O
1MB	O
of	O
RAM	B-Architecture
,	O
this	O
already	O
being	O
provided	O
by	O
the	O
upgraded	O
32016	B-Device
Second	O
Processor	O
product	O
known	O
as	O
the	O
Cambridge	O
Co-Processor	O
.	O
</s>
<s>
Unlike	O
previously	O
released	O
Acorn	O
microcomputers	B-Architecture
,	O
it	O
was	O
sold	O
by	O
Acorn	O
as	O
a	O
complete	O
system	O
bundled	O
with	O
disk	O
drive	O
and	O
monitor	O
(	O
and	O
the	O
first	O
high-volume	O
system	O
from	O
Acorn	O
to	O
do	O
so	O
,	O
preceded	O
by	O
the	O
unreleased	O
Acorn	B-Device
Business	I-Device
Computer	I-Device
and	O
low-volume	O
Acorn	B-Device
Cambridge	I-Device
Workstation	I-Device
)	O
,	O
aiming	O
to	O
provide	O
a	O
"	O
one	O
plug	O
"	O
solution	O
that	O
had	O
,	O
at	B-Operating_System
the	O
time	O
of	O
release	O
,	O
been	O
successfully	O
popularised	O
by	O
manufacturers	O
such	O
as	O
Amstrad	O
.	O
</s>
<s>
Although	O
the	O
Compact	O
has	O
a	O
"	O
three	O
box	O
"	O
arrangement	O
,	O
the	O
main	O
functionality	O
of	O
the	O
system	O
is	O
actually	O
provided	O
in	O
the	O
keyboard	B-Device
unit	O
,	O
much	O
like	O
the	O
Master	O
128	O
,	O
but	O
rather	O
reduced	O
in	O
size	O
in	O
comparison	O
to	O
the	O
Master	O
128	O
and	O
Model	B-Device
B	I-Device
,	O
being	O
styled	O
on	O
the	O
Acorn	B-Device
Communicator	I-Device
.	O
</s>
<s>
The	O
unit	O
under	O
the	O
monitor	O
housed	O
a	O
-inch	O
floppy	B-Device
disk	I-Device
drive	I-Device
and	O
the	O
system	O
power	O
supply	O
.	O
</s>
<s>
However	O
,	O
the	O
colour	O
monitor	O
also	O
provided	O
a	O
SCART	B-Protocol
connector	I-Protocol
,	O
anticipating	O
"	O
future	O
applications	O
"	O
employing	O
more	O
colours	O
and	O
even	O
"	O
overlaying	O
video	O
pictures	O
"	O
.	O
</s>
<s>
A	O
multifunction	O
mouse	O
and	O
joystick	B-Device
port	O
was	O
provided	O
as	O
a	O
9-pin	B-Protocol
D	I-Protocol
type	I-Protocol
with	O
its	O
function	O
configured	O
in	O
software	O
.	O
</s>
<s>
However	O
,	O
the	O
machine	O
did	O
include	O
a	O
50-way	O
expansion	O
edge	O
connector	O
on	O
the	O
right	O
side	O
of	O
the	O
keyboard	B-Device
,	O
that	O
was	O
similar	O
to	O
cartridge	O
socket	O
#3	O
on	O
a	O
Master	O
128	O
.	O
</s>
<s>
Various	O
third-party	O
suppliers	O
restored	O
some	O
of	O
the	O
removed	O
functionality	O
via	O
this	O
connector	O
such	O
as	O
support	O
for	O
Electron	O
and	O
Master	O
128	O
cartridges	O
and	O
the	O
provision	O
of	O
various	O
BBC	B-Device
Micro	I-Device
expansion	O
connectors	O
.	O
</s>
<s>
For	O
example	O
,	O
Morley	O
Electronics	O
employed	O
the	O
mouse/joystick	O
port	O
to	O
attach	O
their	O
teletext	O
adapter	O
to	O
the	O
Compact	O
.	O
</s>
<s>
Acorn	O
reportedly	O
designed	O
the	O
Compact	O
to	O
appeal	O
to	O
home	O
users	O
and	O
to	O
primary	O
education	O
,	O
with	O
the	O
single-plug	O
power	O
connection	O
regarded	O
as	O
more	O
convenient	O
for	O
setting	O
up	O
a	O
machine	O
that	O
might	O
be	O
moved	O
around	O
in	O
a	O
school	O
,	O
and	O
the	O
choice	O
of	O
-inch	O
discs	O
using	O
the	O
ADFS	B-Device
format	O
was	O
regarded	O
as	O
conducive	O
to	O
"	O
handling	O
many	O
small	O
files	O
"	O
and	O
"	O
distinguishing	O
between	O
different	O
topics	O
or	O
users	O
on	O
the	O
same	O
disc	O
"	O
.	O
</s>
<s>
In	O
an	O
effort	O
to	O
increase	O
sales	O
of	O
the	O
Compact	O
to	O
education	O
,	O
Acorn	O
reduced	O
the	O
price	O
of	O
the	O
machine	O
in	O
late	O
1987	O
,	O
bundling	O
the	O
Mertec	O
Compact	O
Companion	O
interface	O
with	O
it	O
to	O
provide	O
the	O
BBC	O
range	O
's	O
traditional	O
expansion	O
connectors	O
,	O
pricing	O
it	O
at	B-Operating_System
£344	O
including	O
VAT	O
without	O
monitor	O
.	O
</s>
<s>
Unlike	O
the	O
other	O
models	O
in	O
the	O
series	O
which	O
provided	O
a	O
battery-backed	O
clock	O
and	O
memory	O
for	O
configuration	O
settings	O
,	O
the	O
Compact	O
utilised	O
EEPROM	O
storage	O
for	O
its	O
configuration	O
with	O
support	O
for	O
only	O
a	O
limited	O
number	O
of	O
writes	O
,	O
making	O
the	O
EEPROMs	O
"	O
a	O
consumable	O
,	O
like	O
a	O
battery	O
"	O
requiring	O
"	O
replacement	O
at	B-Operating_System
intervals	O
"	O
.	O
</s>
<s>
Hence	O
,	O
it	O
had	O
no	O
built-in	O
real-time	O
clock	O
facility	O
,	O
although	O
the	O
time	O
could	O
be	O
fetched	O
via	O
Econet	B-Device
where	O
available	O
,	O
being	O
applied	O
to	O
ADFS	B-Device
file	O
timestamps	O
.	O
</s>
<s>
Only	O
the	O
ADFS	B-Device
Version	O
2	O
filing	O
system	O
was	O
supplied	O
as	O
standard	O
,	O
running	O
via	O
a	O
Western	O
Digital	O
1772	O
chip	O
(	O
a	O
faster	O
version	O
of	O
the	O
widely	O
used	O
1770	O
)	O
,	O
though	O
it	O
is	O
possible	O
to	O
load	O
a	O
1770	O
DFS	B-Application
ROM	B-Device
into	O
sideways	B-General_Concept
RAM	I-General_Concept
,	O
or	O
to	O
insert	O
a	O
ROM	B-Device
or	O
EPROM	O
containing	O
it	O
.	O
</s>
<s>
{{	O
blockquote|The	O
(	O
9-pin	O
joystick	B-Device
)	O
port	O
is	O
derived	O
from	O
port	O
B	O
of	O
the	O
user	O
VIA	O
,	O
without	O
extra	O
buffering	O
,	O
and	O
may	O
thus	O
also	O
be	O
used	O
for	O
output	O
as	O
well	O
as	O
input	O
.	O
</s>
<s>
For	O
applications	O
requiring	O
the	O
use	O
of	O
the	O
'	O
USER	O
PORT	O
 '	O
as	O
used	O
in	O
other	O
BBC	B-Device
computers	I-Device
,	O
the	O
three	O
signals	O
that	O
are	O
not	O
provided	O
on	O
the	O
joystick	B-Device
port	O
(	O
PB5	O
,	O
PB6	O
and	O
PB7	O
)	O
are	O
available	O
on	O
the	O
expansion	O
port.	O
|source	O
=	O
Master	O
Series	O
Service	O
Manual	O
,	O
pp	O
.	O
</s>
<s>
The	O
keyboard	B-Device
on	O
the	O
Compact	O
was	O
the	O
first	O
to	O
move	O
away	O
from	O
using	O
the	O
traditional	O
"	O
sprung-key	O
"	O
keyswitch	O
design	O
used	O
by	O
the	O
rest	O
of	O
the	O
BBC	B-Device
Micro	I-Device
family	O
.	O
</s>
<s>
This	O
later	O
BASIC	O
ROM	B-Device
included	O
the	O
updated	O
message	O
(	O
vs	O
previous	O
BBC	B-Language
BASIC	I-Language
ROMs	O
)	O
:	O
</s>
<s>
The	O
Compact	O
included	O
Acorn	O
's	O
first	O
publicly	O
available	O
GUI	B-Application
.	O
</s>
<s>
Little	O
commercial	O
software	O
,	O
beyond	O
that	O
included	O
on	O
the	O
Welcome	O
disk	O
,	O
was	O
ever	O
made	O
available	O
for	O
the	O
system	O
,	O
despite	O
the	O
claim	O
by	O
Acorn	O
at	B-Operating_System
the	O
time	O
that	O
over	O
100	O
titles	O
would	O
be	O
"	O
set	O
for	O
distribution	O
on	O
3.5in	O
disc	O
format	O
for	O
the	O
Compact	O
launch	O
"	O
.	O
</s>
<s>
The	O
most	O
avid	O
supporter	O
of	O
the	O
Master	O
Compact	O
appeared	O
to	O
be	O
Superior	B-Device
Software	I-Device
,	O
who	O
produced	O
and	O
specifically	O
labelled	O
their	O
games	O
as	O
Master	O
Compact	O
compatible	O
.	O
</s>
<s>
Software	O
for	O
the	O
Compact	O
was	O
comparatively	O
expensive	O
(	O
typically	O
£20	O
for	O
a	O
game	O
)	O
due	O
to	O
the	O
much	O
lower	O
demand	O
for	O
the	O
-inch	O
disk	O
format	O
(	O
-inch	O
was	O
the	O
standard	O
for	O
the	O
Master	O
and	O
earlier	O
BBC	B-Device
Micro	I-Device
)	O
.	O
</s>
<s>
Olivetti	O
were	O
named	O
as	O
being	O
interested	O
in	O
releasing	O
a	O
version	O
of	O
the	O
Master	O
Compact	O
in	O
Italy	O
under	O
the	O
Olivetti	O
Prodest	O
brand	O
,	O
subsequently	O
announcing	O
the	O
model	O
as	O
the	O
aimed	O
at	B-Operating_System
the	O
home	O
and	O
small	O
business	O
markets	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
localisation	O
of	O
the	O
system	O
itself	O
,	O
various	O
applications	O
were	O
localised	O
for	O
the	O
PC128S	O
including	O
View	O
,	O
ViewSheet	B-Language
,	O
ViewPlot	O
,	O
and	O
ViewIndex	O
,	O
along	O
with	O
a	O
number	O
of	O
games	O
including	O
Aviator	O
,	O
Revs	O
,	O
XOR	O
,	O
and	O
Doctor	O
Who	O
and	O
the	O
Mines	O
of	O
Terror	O
.	O
</s>
<s>
Pricing	O
for	O
the	O
started	O
at	B-Operating_System
995,000	O
lire	O
for	O
a	O
system	O
with	O
monochrome	O
monitor	O
or	O
1,295,000	O
lire	O
with	O
a	O
colour	O
monitor	O
(	O
equivalent	O
to	O
€	O
and	O
€	O
respectively	O
in	O
today	O
's	O
prices	O
,	O
adjusted	O
for	O
inflation	O
)	O
.	O
</s>
<s>
128	O
KB	O
ROM	B-Device
in	O
the	O
Master	O
128	O
,	O
Master	O
Turbo	O
,	O
and	O
Master	O
512	O
.	O
</s>
<s>
Comprising	O
a	O
16KB	O
MOS	O
(	O
Machine	O
Operating	B-General_Concept
System	I-General_Concept
)	O
,	O
always	O
accessible	O
,	O
and	O
seven	O
16KB	O
sideways	B-General_Concept
ROMs	O
,	O
any	O
one	O
of	O
which	O
could	O
be	O
paged	O
into	O
memory	O
at	B-Operating_System
a	O
time	O
:	O
</s>
<s>
64	O
KB	O
ROM	B-Device
in	O
the	O
Master	O
ET	O
.	O
</s>
<s>
Comprising	O
a	O
16KB	O
MOS	O
(	O
Machine	O
Operating	B-General_Concept
System	I-General_Concept
)	O
,	O
always	O
accessible	O
,	O
and	O
three	O
16KB	O
sideways	B-General_Concept
ROMs	O
,	O
any	O
one	O
of	O
which	O
could	O
be	O
paged	O
into	O
memory	O
at	B-Operating_System
a	O
time	O
:	O
</s>
<s>
128	O
KB	O
RAM	B-Architecture
,	O
comprising	O
:	O
</s>
<s>
Full-travel	O
keyboard	B-Device
with	O
a	O
top	O
row	O
of	O
ten	O
red-orange	O
function	O
keysƒ0	O
–	O
ƒ9	O
and	O
AT-style	O
numeric	O
keypad	O
.	O
</s>
<s>
Highly	O
configurable	O
graphics	O
display	O
based	O
on	O
the	O
Motorola	B-General_Concept
6845	I-General_Concept
.	O
</s>
<s>
Unlike	O
on	O
the	O
original	O
BBC	B-Device
Micro	I-Device
,	O
separate	O
video	O
RAM	B-Architecture
was	O
used	O
so	O
that	O
choosing	O
a	O
high-resolution	O
mode	O
did	O
not	O
reduce	O
the	O
amount	O
of	O
available	O
user	O
RAM	B-Architecture
.	O
</s>
<s>
(	O
However	O
,	O
user	O
RAM	B-Architecture
could	O
still	O
be	O
used	O
as	O
the	O
video	O
buffer	O
if	O
required	O
,	O
in	O
order	O
to	O
allow	O
effects	O
such	O
as	O
double	O
buffering	O
.	O
)	O
</s>
<s>
Eight	O
graphics	O
modes	O
were	O
provided	O
by	O
the	O
system	O
ROM	B-Device
:	O
</s>
<s>
To	O
save	O
RAM	B-Architecture
,	O
the	O
count	O
of	O
lines	O
was	O
reduced	O
from	O
32	O
to	O
25	O
.	O
</s>
<s>
This	O
creates	O
characteristic	O
black	O
lines	O
between	O
the	O
rows	O
of	O
text	O
when	O
a	O
different	O
background	O
colour	O
is	O
set	O
,	O
and	O
a	O
blank	O
gap	O
at	B-Operating_System
the	O
bottom	O
of	O
the	O
display	O
with	O
the	O
left-over	O
pixels	O
.	O
</s>
<s>
Mode	O
7	O
's	O
Teletext	O
capability	O
was	O
provided	O
by	O
a	O
Mullard	B-General_Concept
SAA5050	I-General_Concept
Teletext	O
chip	O
.	O
</s>
<s>
proprietary	O
"	O
Tube	B-Device
"	O
interface	O
for	O
internal	O
or	O
external	O
second	O
CPU	O
(	O
in	O
the	O
Master	O
512	O
model	O
,	O
an	O
80186	B-Device
was	O
used	O
;	O
other	O
options	O
included	O
a	O
3MHz	O
extra	O
6502	B-General_Concept
,	O
a	O
Zilog	B-General_Concept
Z80	I-General_Concept
for	O
e.g.	O
</s>
<s>
For	O
example	O
,	O
the	O
light-pen	O
input	O
would	O
directly	O
halt	O
a	O
counter	O
which	O
was	O
started	O
by	O
the	O
start	O
of	O
the	O
vertical	O
sweep	O
of	O
each	O
display	O
refresh	O
,	O
making	O
calculation	O
of	O
where	O
the	O
lightpen	B-Device
was	O
touching	O
the	O
screen	O
little	O
more	O
than	O
a	O
simple	O
divide/remainder	O
operation	O
.	O
</s>
<s>
Likewise	O
,	O
the	O
motor	O
control	O
relay	O
for	O
the	O
audio	B-Device
cassette	I-Device
tape	I-Device
was	O
controlled	O
by	O
a	O
simple	O
command	O
and	O
could	O
be	O
readily	O
used	O
in	O
numerous	O
control	O
applications	O
.	O
</s>
