Equinox Megaport serial boards

[Gary Blumenstein]

I am posting the following message on behalf of my friend, Chris Lukas
of Continental Computer Systems.  Yes, I know we can't advertise
on the net, but it was my feeling that this information would be valuable in
and of itself for general interest.

It is directed to all those people who have tried Computone, Anvil,
Digiboard, Stargate, Hostess, or Arnet and have found problems:

-------------------------< begin >-------------------------------------

The Equinox Megaport 24 port card (AT bus) is finally available.

This card is powered by a custom ASIC (application specific IC)
processor designed by Equinox.  This processor has been produced by
Equinox for two years and powers thousands of their data switch
modules.  In fact, the processor will in the future support all data
switch functions as well as multiport board functions.

This is the only board capable of pushing over 3800 characters per
second out of all of its ports simultaneously.  Computone and Anvil,
besides not being able to run UUCP/Telebit, do not achieve an actual
38400 baud.  The other boards on the market do even poorer than these
two.  At 96 ports in a system (4 boards) the boards can push 3650 cps
out of all 96 ports simultaneously.  All this speed is no surprise,
given the ASIC processor optimized for serial I/O.  This is not a
general purpose processor (most other boards use the 80186), but an
I/O engine.  This board is an excellent board for UUCP, because of
its extraordinary throughput.

The card has an extremely fast memory mapped i/o interface to the bus,
and can support 16MHz bus speeds.  Any card that uses DMA or I/O
on the AT bus is automatically slow and inefficient, since DMA or I/O
cycles are much longer than 16 bit memory cycles on the AT bus.  Also,
unlike any other boards, any number (1-8) of Equinox cards only uses
two 64K non-contiguous memory address ranges in total.  This is in
contrast to many other cards, which use 64K of memory addresses per
16 port board!  If you want to have 16 or more MB of memory in an
ISA 386, you have precious few memory addresses open on the the bus
(and they are all in the range from 640K-1024K).  Typically, only 2 64K
address ranges are free below 1MB (ethernet cards are also using memory
mapped I/O these days and are addressed below 1024K).  So if a system
has 16MB of memory, it can only have 32 ports (2 16 port boards).  In
the same address space (2 64K ranges) you could have 8 equinox boards
(for a maximum of 192 ports per system).

There is no firmware (ROMs).  Most other manufacturers put firmware
on the board, which makes it much more difficult to fix problems on
the board.  There are no switches or jumpers to set.  Up to 8 boards
in one system are supported (for a total of 192 ports) all on one
interrupt (of course it can be set for almost any interrupt).  The
card or cards can run without interrupts (in a polled mode of
operation).  Polling is much more efficient than interrupts if there
is a LOT of I/O.  Also, there is an additional bus (a 10 pin ribbon
cable) between cards so that cards can communicate between each other.
Again, this is a board without switches and jumpers.  Installation
requires nothing more than inserting the card, and running install.

The Equinox Megaport 24 port board supports the usual features such
as transparent print, automatic installation (no editing of files)
via "install".  Note that currently custom(ADM) is not supported
(custom is a bad way to install drivers anyway).  The software
installation is the cleanest and easiest we have seen yet.

As far as I/O loading, we thought we had seen it all with Computone
and Anvil both at 0.8 seconds CPU time per 100Kchars.  The Equinox
Megaport is 0.1 seconds per 100Kchars.  This is merely 8 times more
efficient than any other boards.  (All results reported using the
SCO time(CP) command).

Since Equinox is a data switch company, there is a universe of
cabling options available.  The board can directly terminate in
24 RJ-11 (6 wire) ports, or can terminate in 2 50 position Amphenol
PBX connectors so that you can use octopuses or harmonicas or data
racks or whatever connection options you want.  They also have the
usual DB-25 termination option also.  All these option greatly ease
the chore of wiring a system.

Driver availability:  SCO XENIX 2.3 386 VPIX drivers now.

SCO UNIX and generic UNIX 3.2 (AT&T, Interactive, Enix) drivers
	early to mid-july.

Of course, Equinox has been making data switches for 10 years, so
they have experience moving data.  Also, Equinox is based in the
US (in Florida), not 5000 miles away.  Since they have been in
business they have not had any financial problems (AAA rated on
D+B for their entire history) unlike Arnet and Computone which
both had severe financial problems.  It is nice to have a stable
vendor for such an important part of the system.

-------------------------------< eof >----------------------------------

If you would like any additional information on these boards, you can reach
Continental at 1(203) 665-1355.  They are located in Newington, CT.
echo $FLAMES >/dev/null
-- 
Gary Blumenstein, UNIX Systems Administrator // CIBA-GEIGY CORPORATION, USA
===========================================================================
Voice: (914) 347-4700                  7 Skyline Drive, Hawthorne, NY 10502
FAX  : (914) 347-5687     uucp: ...{philabs, gaboon}!crpmks!{sysadm, garyb}