<s>
The	O
REX	B-Application
6000	I-Application
is	O
an	O
ultra-thin	O
Personal	B-Application
Digital	I-Application
Assistant	I-Application
(	O
PDA	B-Application
)	O
produced	O
by	O
Xircom	O
,	O
and	O
later	O
Intel	O
,	O
from	O
about	O
2000	O
to	O
2001	O
.	O
</s>
<s>
Its	O
primary	O
claim	O
to	O
fame	O
is	O
as	O
"	O
The	O
world	O
's	O
smallest	O
full-function	O
PDA	B-Application
"	O
,	O
due	O
to	O
its	O
unusual	O
physical	O
configuration	O
as	O
a	O
PC	B-Architecture
card	I-Architecture
Type-II	O
card	O
(	O
8.57	O
×	O
5.40	O
×	O
.5cm	O
;	O
40	O
g	O
)	O
.	O
</s>
<s>
The	O
REX	O
may	O
be	O
synchronized	O
by	O
inserting	O
it	O
in	O
a	O
host	O
PC	B-Device
's	O
PCMCIA/PC	O
-card	O
slot	O
.	O
</s>
<s>
Docking	O
stations	O
were	O
manufactured	O
for	O
connection	O
to	O
hosts	O
without	O
PC	B-Architecture
card	I-Architecture
Type-II	O
slots	O
,	O
which	O
allows	O
the	O
REX	O
to	O
be	O
connected	O
via	O
a	O
USB	B-Protocol
or	O
serial	B-Protocol
connection	O
.	O
</s>
<s>
The	O
REX	B-Application
6000	I-Application
is	O
the	O
successor	O
to	O
the	O
Franklin	O
REX	B-Application
5000	I-Application
,	O
with	O
a	O
notable	O
difference	O
being	O
the	O
addition	O
of	O
a	O
touch	B-Device
screen	I-Device
.	O
</s>
<s>
In	O
addition	O
,	O
it	O
is	O
possible	O
to	O
remove	O
and	O
install	O
executable	O
code	O
(	O
including	O
both	O
custom	O
applications	O
and	O
the	O
operating	B-General_Concept
system	I-General_Concept
itself	O
)	O
.	O
</s>
<s>
As	O
with	O
the	O
earlier	O
models	O
,	O
the	O
REX	B-Application
6000	I-Application
hardware	O
was	O
developed	O
by	O
the	O
Citizen	O
Watch	O
Company	O
of	O
Japan	O
,	O
marketed	O
as	O
the	O
"	O
DataSlim-2	O
"	O
.	O
</s>
<s>
The	O
firmware	O
for	O
previous	O
REX	O
models	O
was	O
written	O
by	O
Starfish	O
Software	O
,	O
but	O
the	O
REX	B-Application
6000	I-Application
,	O
though	O
modeled	O
on	O
previous	O
versions	O
,	O
included	O
a	O
complete	O
re-write	O
of	O
the	O
firmware	O
.	O
</s>
<s>
The	O
REX	B-Application
6000	I-Application
does	O
not	O
support	O
handwriting	B-Application
recognition	I-Application
and	O
to	O
enter	O
data	O
,	O
a	O
virtual	B-Device
keyboard	I-Device
is	O
used	O
.	O
</s>
<s>
The	O
standard	O
REX	B-Application
6000	I-Application
has	O
an	O
American	O
keyboard	O
layout	O
,	O
although	O
third-party	O
software	O
allows	O
for	O
other	O
keyboard	O
layouts	O
.	O
</s>
<s>
Third-party	O
software	O
(	O
"	O
add-ins	O
"	O
)	O
include	O
games	O
,	O
painting	O
programs	O
,	O
spreadsheets	B-Application
and	O
replacements	O
or	O
improvements	O
of	O
the	O
pre-installed	O
software	O
.	O
</s>
<s>
Most	O
third-party	O
software	O
has	O
been	O
developed	O
in	O
spare	O
time	O
by	O
interested	O
users	O
using	O
customized	O
versions	O
of	O
the	O
Z88DK	B-Device
compiler	B-Language
or	O
the	O
Small	B-Application
Device	I-Application
C	I-Application
Compiler	I-Application
(	O
SDCC	O
)	O
.	O
</s>
<s>
The	O
earliest	O
release	O
of	O
the	O
REX	B-Application
6000	I-Application
had	O
1MB	O
of	O
flash	B-Device
memory	I-Device
,	O
while	O
later	O
releases	O
doubled	O
this	O
to	O
2MB	O
.	O
</s>
<s>
(	O
Earlier	O
REXes	O
stored	O
user	O
data	O
in	O
RAM	B-Architecture
with	O
the	O
operating	B-General_Concept
system	I-General_Concept
in	O
ROM	B-Device
.	O
)	O
</s>
<s>
The	O
REX	O
has	O
32	O
KB	O
of	O
RAM	B-Architecture
,	O
but	O
only	O
12KB	O
is	O
available	O
for	O
application	O
developers	O
.	O
</s>
<s>
It	O
uses	O
a	O
4.3MHz	O
Toshiba	O
microprocessor	B-Architecture
compatible	O
to	O
the	O
Zilog	B-General_Concept
Z80	I-General_Concept
,	O
has	O
a	O
240	O
×	O
120	O
pixel	B-Algorithm
monochrome	O
LCD	B-Device
,	O
and	O
is	O
capable	O
of	O
providing	O
beep	O
sounds	O
to	O
deliver	O
alarms	O
and	O
reminders	O
.	O
</s>
<s>
The	O
REX	B-Application
6000	I-Application
is	O
powered	O
by	O
two	O
button-type	O
CR2016	O
lithium	B-Language
cells	O
.	O
</s>
