<s>
The	O
HP-18C	B-Device
was	O
a	O
Hewlett-Packard	O
business	O
calculator	B-Application
which	O
was	O
quickly	O
followed	O
by	O
the	O
very	O
similar	O
but	O
greatly	O
improved	O
HP-19B	B-Device
.	O
</s>
<s>
The	O
HP-18C	B-Device
was	O
HP	O
's	O
first	O
RPL-based	O
calculator	B-Application
internally	O
,	O
even	O
though	O
this	O
was	O
not	O
visible	O
on	O
user-level	O
in	O
this	O
non	O
user-programmable	O
model	O
.	O
</s>
<s>
The	O
user	O
did	O
have	O
a	O
solver	O
(	O
another	O
HP	O
first	O
)	O
available	O
,	O
but	O
only	O
had	O
about	O
1.5	O
KB	O
of	O
continuous	B-Device
memory	I-Device
available	O
to	O
store	O
equations	O
.	O
</s>
<s>
The	O
calculator	B-Application
had	O
many	O
functions	O
buried	O
in	O
a	O
menu	O
structure	O
.	O
</s>
<s>
The	O
HP-18C	B-Device
was	O
introduced	O
in	O
June	O
1986	O
.	O
</s>
