[comp.sys.amiga.hardware] Networking and A500

mkd@mtunh.ATT.COM (Mark Darby) (08/03/90)

Well, I finally got a surprise in the latest issue of Amazing Computing.
There's an ad for network adapters for the A2000 AND the A500 from GVP.
Somebody's finally made a networking card for the A500, which I think
is a good move on GVP's part.  The A500 would make a convenient,
inexpensive networked workstation.  Definitely suitable for the education
environment, but I'm not so sure about the business environment.  That's
only dependent upon the applications used.

One thing that caught my interest, though.  If I read the ad correctly
(it's on page 7 of the August 1990 issue of AC), the A500 adapter card
would only support thin coax ethernet (Cheapernet).  This I can understand
for electrical reasons.  An AUI connection (the DB-15 connector for 
connection to external network transceivers via AUI cable) requires a 12 volt
supply which must be able to source 500mA minimum.  Everyone's quite aware
of the limited 12V supply provided in a stock A500, so the AUI connector was
not implemented.  The Cheapernet connection looks as though it's based upon
a National DP8392 Coax Transceiver IC, which requires -9V supply.  A
DC-to-DC converter is available to convert +5V to -9V, so the only supply
that is needed for the board is +5V (unless there's something on the board
which requires -5V, I don't know).

Of course, without the AUI connector, the 500 is locked out of direct 
connection to alternate media networks.  So the market for cheapernet-only
network adapter cards for the A500 would seem limited. 
Cheapernet is meant to be a "cheaper" networking alternative to thick-coax
Ethernet, and the pairing of the "cheaper" networking scheme to an
"inexpensive" networked station is valid.  However, it would be nice to
provide some sort of alternative for the network board customer other than
Cheapernet.

Enter "10BASE-T."

Twisted Pair Ethernet networking is becoming the gem of
the Ethernet networking industry.  Many equipment vendors support it,
many IC manufacturers support it.  I think it would be advantagous for GVP
(or any other A500 networking board manufacturer) to provide both
Cheapernet and 10BASE-T on the same board.  

1) It gives the user a choice depending upon his environment.  Granted,
   the flexibility is still not as good as it would be if the board had
   an AUI connector, but at least there is a choice between two relatively low
   cost networking alternatives.  

2) A number of chip manufacturers provide 10BASE-T silicon that run on +5V
   only.  This is something that the A500 can take advantage of, considering
   it's power supply limitations.

I've always wanted to see networking come to the Amiga, INCLUDING the 500.
I'm an Amiga 500 owner/user.  Doesn't it show? ;-)

I'm off my soapbox now!  Comments, anyone? (GVP, Commodore, etc?)
----------------------------------------------------------------------------
Mark K. Darby
AT&T Bell Laboratories                     (201)957-2706
200 Laurel Ave.                  att!mtunh!mkd or mkd@mtunh.att.com
Middletown, NJ 07748                              

Disclaimer:  I speak for no one but myself.