<s>
The	O
COMX-35	B-Device
was	O
a	O
home	O
computer	O
that	O
was	O
one	O
of	O
the	O
very	O
few	O
systems	O
to	O
use	O
the	O
RCA	B-General_Concept
1802	I-General_Concept
microprocessor	B-Architecture
,	O
the	O
same	O
microprocessor	B-Architecture
that	O
is	O
also	O
used	O
in	O
some	O
space	O
probes	O
.	O
</s>
<s>
The	O
COMX-35	B-Device
had	O
a	O
keyboard	O
with	O
an	O
integrated	O
joystick	B-Device
in	O
place	O
of	O
cursor	O
keys	O
.	O
</s>
<s>
COMX-35	B-Device
was	O
manufactured	O
in	O
Hong	O
Kong	O
by	O
COMX	O
World	O
Operations	O
Ltd	O
and	O
was	O
released	O
in	O
the	O
Netherlands	O
,	O
the	O
United	O
Kingdom	O
,	O
Sweden	O
,	O
New	O
Zealand	O
,	O
Australia	O
,	O
Finland	O
,	O
Norway	O
,	O
Italy	O
,	O
Singapore	O
,	O
Turkey	O
and	O
the	O
People	O
's	O
Republic	O
of	O
China	O
.	O
</s>
<s>
2	O
channels	O
:	O
one	O
for	O
tone	O
generation	O
with	O
a	O
span	O
of	O
8	O
octaves	B-Language
,	O
and	O
1	O
for	O
special	O
effect/white	O
noise	O
.	O
</s>
<s>
The	O
COMX-35	B-Device
has	O
of	O
RAM	B-Architecture
.	O
</s>
<s>
It	O
consists	O
of	O
of	O
User	O
RAM	B-Architecture
of	O
which	O
roughly	O
is	O
available	O
for	O
BASIC	O
code	O
,	O
with	O
the	O
rest	O
reserved	O
for	O
use	O
by	O
the	O
BASIC	O
System	O
ROM	B-Device
.	O
</s>
<s>
The	O
remaining	O
of	O
RAM	B-Architecture
is	O
used	O
by	O
the	O
Video	B-General_Concept
Interface	I-General_Concept
System	I-General_Concept
.	O
</s>
<s>
The	O
COMX-35	B-Device
uses	O
the	O
RCA	O
CDP1869	O
and	O
CDP1870	O
Video	B-General_Concept
Interface	I-General_Concept
System	I-General_Concept
(	O
VIS	O
)	O
,	O
consisting	O
of	O
the	O
CDP1869	O
address	O
and	O
sound	O
generator	O
and	O
the	O
CDP1870	O
colour	O
video	O
generator	O
.	O
</s>
<s>
The	O
COMX-35	B-Device
automatically	O
detects	O
the	O
Refresh	O
rate	O
.	O
</s>
<s>
The	O
VIS	O
runs	O
on	O
in	O
PAL	B-Language
and	O
in	O
NTSC	O
.	O
</s>
<s>
This	O
frequency	O
is	O
halved	O
and	O
used	O
to	O
clock	O
the	O
CPU	B-General_Concept
.	O
</s>
<s>
Video	O
memory	O
can	O
only	O
be	O
accessed	O
during	O
the	O
non	O
display	O
period	O
,	O
which	O
allows	O
for	O
execution	O
of	O
2160	O
machine	O
cycles	O
in	O
PAL	B-Language
and	O
1574	O
cycles	O
in	O
NTSC	O
.	O
</s>
<s>
The	O
Video	O
memory	O
is	O
divided	O
into	O
RAM	B-Architecture
page	O
memory	O
and	O
RAM	B-Architecture
character	O
memory	O
.	O
</s>
<s>
The	O
COMX-35	B-Device
came	O
in	O
two	O
colours	O
,	O
with	O
either	O
a	O
white	O
or	O
black	O
keyboard	O
.	O
</s>
<s>
A	O
second	O
model	O
called	O
the	O
COMX	O
PC1	O
improved	O
the	O
keyboard	O
and	O
added	O
a	O
joystick	B-Device
port	O
.	O
</s>
<s>
The	O
COMX-35	B-Device
has	O
one	O
44-pin	O
external	O
connector	O
for	O
additional	O
expansion	O
options	O
in	O
the	O
form	O
of	O
interface	O
cards	O
.	O
</s>
<s>
Expansion	O
box	O
The	O
expansion	O
box	O
allowed	O
up	O
to	O
4	O
interface	O
cards	O
to	O
be	O
connected	O
to	O
the	O
COMX-35	B-Device
.	O
</s>
<s>
The	O
expansion	O
box	O
also	O
included	O
a	O
firmware	B-Application
ROM	B-Device
connected	O
to	O
memory	O
location	O
@E000	O
-	O
@EFFF	O
which	O
extended	O
basic	O
with	O
commands	O
and	O
logic	O
to	O
switch	O
between	O
different	O
interface	O
cards	O
.	O
</s>
<s>
The	O
DOS	O
ROM	B-Device
was	O
selected	O
between	O
address	O
C000-DFFF	O
and	O
was	O
also	O
mapped	O
over	O
address	O
DD0-DDF	O
of	O
the	O
basic	O
ROM	B-Device
.	O
</s>
<s>
Depending	O
on	O
what	O
type	O
of	O
printer	O
was	O
connected	O
the	O
firmware	B-Application
ROM	B-Device
was	O
selected	O
either	O
with	O
the	O
parallel	O
firmware	B-Application
between	O
memory	O
location	O
@C000	O
-	O
@CFFF	O
and	O
the	O
serial	O
firmware	B-Application
between	O
memory	O
location	O
@D000	O
-	O
@DFFF	O
or	O
the	O
other	O
way	O
around	O
.	O
</s>
<s>
32K	O
RAM	B-Architecture
card	O
The	O
COMX	O
RAM	B-Architecture
card	O
placed	O
additional	O
RAM	B-Architecture
from	O
address	O
@C000	O
to	O
@DFFF	O
,	O
i.e.	O
</s>
<s>
Bit	O
5	O
and	O
6	O
were	O
used	O
for	O
the	O
RAM	B-Architecture
bank	O
selection	O
(	O
bit	O
1	O
to	O
4	O
were	O
used	O
for	O
the	O
expansion	O
box	O
slot	O
selection	O
)	O
.	O
</s>
<s>
The	O
MC6845	B-General_Concept
was	O
used	O
as	O
video	B-General_Concept
chip	I-General_Concept
.	O
</s>
<s>
The	O
card	O
had	O
connections	O
for	O
2	O
joysticks	B-Device
and	O
came	O
with	O
a	O
simple	O
game	O
and	O
supporting	O
software	O
.	O
</s>
<s>
West	O
Electronics	O
,	O
the	O
company	O
importing	O
the	O
COMX-35	B-Device
in	O
The	O
Netherlands	O
,	O
provided	O
most	O
of	O
their	O
software	O
for	O
free	O
and	O
without	O
copyrights	O
(	O
or	O
for	O
a	O
small	O
fee	O
for	O
tape	O
,	O
disk	O
and/or	O
shipment	O
)	O
.	O
</s>
<s>
Homebrew	O
development	O
for	O
the	O
COMX-35	B-Device
is	O
still	O
active	O
in	O
The	O
Netherlands	O
as	O
a	O
result	O
.	O
</s>
<s>
The	O
most	O
popular	O
game	O
on	O
the	O
COMX-35	B-Device
was	O
'	O
Worm	O
 '	O
(	O
known	O
in	O
The	O
Netherlands	O
as	O
'	O
Eet	O
een	O
wurm	O
 '	O
)	O
.	O
</s>
<s>
This	O
was	O
a	O
very	O
basic	O
adaptation	O
of	O
Snake	B-Application
(	O
video	O
game	O
genre	O
)	O
.	O
</s>
<s>
One	O
can	O
crash	O
the	O
COMX-35	B-Device
by	O
simply	O
typing	O
65535	O
as	O
the	O
line	O
number	O
in	O
BASIC	O
.	O
</s>
<s>
Emma	O
02	O
is	O
capable	O
of	O
emulating	O
the	O
COMX-35	B-Device
along	O
with	O
other	O
systems	O
which	O
share	O
a	O
similar	O
chip-set	O
.	O
</s>
