Nabu Network
Encyclopedia
The NABU Network was an early home computer system which was linked to a precursor of the Internet, operating over cable TV. It operated from 1982 to 1985, primarily in Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...

, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

. Its functionality was then revolutionary, though it was not a commercial success.

Functionality

Families, schools, or individuals would purchase a NABU Network PC, which would be connected via cable TV to NABU's servers. In addition to normal PC capabilities of the time, the computer could download software and information content through the cable feed and could upload primitive information back up to the servers. Applications included games, the programming language Logo, news/current events, and rudimentary PC banking/shopping. At its peak, approximately 100 applications were available.

The Nabu Network PC cost $950 CAD
Canadian dollar
The Canadian dollar is the currency of Canada. As of 2007, the Canadian dollar is the 7th most traded currency in the world. It is abbreviated with the dollar sign $, or C$ to distinguish it from other dollar-denominated currencies...

, approximately the same price as the wildly successful Commodore 64
Commodore 64
The Commodore 64 is an 8-bit home computer introduced by Commodore International in January 1982.Volume production started in the spring of 1982, with machines being released on to the market in August at a price of US$595...

 at the time, and the network service cost $8 to $10 per month.http://www.pcworld.ca/pages/newscolumn.aspx?id=f83fbbf00a01040800fa55e65be39dac

Hardware

The heart of a NABU (which stands for Natural Access to Bi-directional Utilities) PC was the Z80A processor chip (running at a then lightning-fast 3.57 MHz) and the cutting-edge TI 9918 video chip, which was able to produce some very good graphics for its time. All this was served up via a Gould SEL mainframe. The logic module included four socketed chips: a TR1865CL-04, a full-duplex UART, an SC87253P 8-bit microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...

, an N8X60N FIFO I/O controller and a pre-programmed ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...

. The remainder of the parts on the board were numerous 74LS series logic ICs. There was an RF module that down-converted signals from the cable connection and up-converted requests to be sent to the server. There were four circuit boards for frequency synthesis, data in and out and RF conversion and dual helical coil bandpass filters.

Download speeds over the cable TV line were up to 6.4 Mbit/second.

By default, the PCs lacked any individual offline storage, but an optional hard drive could be purchased.

Business success

The NABU service first became available in 1982 through Ottawa Cablevision, through the efforts of John Kelly and Bruce Hempell. The project was heavily subsidized by the Canadian government. A major weakness of the Ottawa network was the strictly one-way connection as it was implemented on Ottawa Cablevision. The cost of upgrading the existing cable infrastructure to a true bi-directional network (NABU was bi-directional but the cable network couldn't support this) was, according to former NABU developer Mike Slinn, "a show-stopper" because the demand just didn't justify the investment – a prime example of the "chicken and the egg" conundrum.

Another network was started in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. However, NABU never achieved commercial success and ceased operation in 1985.

External links

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