<s>
HYPERchannel	B-General_Concept
,	O
sometimes	O
rendered	O
Hyperchannel	B-General_Concept
,	O
was	O
a	O
local	B-General_Concept
area	I-General_Concept
networking	I-General_Concept
system	O
for	O
mainframe	B-Architecture
computers	I-Architecture
,	O
especially	O
supercomputers	B-Architecture
,	O
introduced	O
by	O
Network	O
Systems	O
Corporation	O
in	O
the	O
1970s	O
.	O
</s>
<s>
It	O
ran	O
at	O
the	O
then-fast	O
speed	O
of	O
50Mbits/second	O
,	O
performance	O
that	O
would	O
not	O
be	O
matched	O
by	O
commodity	O
hardware	O
until	O
the	O
introduction	O
of	O
Fast	B-Protocol
Ethernet	I-Protocol
in	O
1995	O
.	O
</s>
<s>
HYPERchannel	B-General_Concept
ran	O
over	O
very	O
thick	O
coax	O
cable	O
or	O
fibre	B-Architecture
optic	I-Architecture
extensions	O
and	O
required	O
adaptor	O
hardware	O
the	O
size	O
of	O
a	O
minicomputer	B-Architecture
.	O
</s>
<s>
Solutions	O
for	O
Control	O
Data	O
,	O
IBM	O
and	O
Cray	O
computers	O
were	O
their	O
primary	O
products	O
,	O
but	O
a	O
wide	O
variety	O
of	O
support	O
emerged	O
in	O
the	O
1980s	O
,	O
including	O
DEC	B-Device
VAX	I-Device
and	O
similar	O
superminicomputers	B-Device
.	O
</s>
<s>
The	O
introduction	O
of	O
10mbit/sec	O
Ethernet	O
in	O
the	O
1980s	O
was	O
a	O
major	O
problem	O
for	O
the	O
HYPERchannel	B-General_Concept
product	O
,	O
one	O
the	O
company	O
never	O
clearly	O
addressed	O
.	O
</s>
<s>
The	O
company	O
introduced	O
products	O
to	O
allow	O
HYPERchannel	B-General_Concept
protocols	O
to	O
travel	O
over	O
Ethernet	O
,	O
and	O
systems	O
that	O
allowed	O
Ethernet-equipped	O
computers	O
to	O
connect	O
to	O
HYPERchannel	B-General_Concept
systems	O
,	O
as	O
well	O
as	O
TCP/IP	B-Protocol
and	O
other	O
standard	O
protocol	O
support	O
.	O
</s>
<s>
"	O
Hyperchannel	B-General_Concept
"	O
referred	O
to	O
an	O
early	O
,	O
proprietary	O
LAN	B-General_Concept
protocol	O
.	O
</s>
<s>
The	O
earlier	O
,	O
"	O
A-series	O
"	O
Hyperchannel	B-General_Concept
"	O
adapter	O
"	O
had	O
a	O
device	O
interface	O
and	O
a	O
trunk	O
(	O
LAN	B-General_Concept
)	O
interface	O
,	O
which	O
could	O
drive	O
up	O
to	O
four	O
coaxial	O
trunks	O
,	O
each	O
carrying	O
50	O
Mbit/s	O
.	O
</s>
<s>
A	O
major	O
product	O
was	O
RDS	O
(	O
Remote	O
Device	O
Support	O
)	O
,	O
in	O
which	O
an	O
IBM	O
mainframe	B-Architecture
could	O
connect	O
to	O
an	O
adapter	O
through	O
its	O
FIPS	O
channel	O
,	O
which	O
would	O
communicate	O
over	O
a	O
trunk	O
to	O
an	O
adapter	O
with	O
a	O
comms	O
link	O
,	O
possibly	O
to	O
another	O
continent	O
,	O
where	O
it	O
could	O
drive	O
a	O
remote	O
FIPS	O
channel	O
to	O
drive	O
IBM	O
peripherals	O
such	O
as	O
tape	O
units	O
,	O
printers	O
and	O
the	O
like	O
.	O
</s>
<s>
The	O
Hyperchannel	B-General_Concept
Trunk	O
was	O
a	O
LAN	B-General_Concept
made	O
of	O
up	O
to	O
four	O
parallel	O
coaxial	O
cables	O
carrying	O
50	O
Mbit/s	O
,	O
which	O
,	O
at	O
the	O
time	O
,	O
was	O
considered	O
bleeding-edge	O
technology	O
.	O
</s>
<s>
There	O
could	O
be	O
many	O
adapters	O
on	O
the	O
trunk	O
,	O
so	O
that	O
,	O
for	O
example	O
,	O
mainframes	B-Architecture
of	O
different	O
types	O
could	O
inter-communicate	O
across	O
the	O
trunk	O
network	O
that	O
could	O
also	O
have	O
an	O
adapter	O
for	O
telecomms	O
links	O
to	O
other	O
locations	O
.	O
</s>
<s>
The	O
A-series	O
adapter	O
was	O
later	O
supplanted	O
by	O
the	O
DX	O
adapter	O
,	O
which	O
was	O
microprocessor-based	O
,	O
and	O
could	O
contain	O
a	O
selection	O
of	O
device	O
cards	O
,	O
trunk	O
boards	O
,	O
link	O
boards	O
,	O
as	O
well	O
as	O
LAN	B-General_Concept
and	O
WAN	O
cards	O
including	O
Ethernet	O
,	O
FDDI	O
,	O
Token	O
Ring	O
,	O
or	O
an	O
IP	O
router	O
board	O
for	O
IP	O
communication	O
,	O
in	O
a	O
chassis	O
of	O
up	O
to	O
16	O
slots	O
.	O
</s>
<s>
As	O
it	O
could	O
contain	O
more	O
than	O
one	O
device	O
interface	O
board	O
,	O
it	O
could	O
handle	O
inter-device	O
communication	O
without	O
resort	O
to	O
the	O
Hyperchannel	B-General_Concept
trunk	O
,	O
which	O
was	O
only	O
retained	O
for	O
communication	O
with	O
legacy	O
equipment	O
.	O
</s>
