Nabu Network

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For other uses, see Nabu (disambiguation).

The Nabu Network was a microcomputer system which was linked to a precursor of the Internet in the 1980s primarily in Ottawa, Canada. It is now obsolete but was then revolutionary, if unsuccessful.

Families would buy a Nabu Network PC, which would be connected via cable TV to Nabu's servers. The PC had all the capabilities of a normal PC, but in addition would 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 primitive PC banking/shopping. Connection speeds were on the order of 6 Mbit/second. The Nabu Network PC cost $950 CAD, approximately the same price as other PCs at the time, and the network service cost $8 to $10 per month.[1]

The project was heavily subsidized by the Canadian government. The Nabu service first became available in 1982 through Ottawa Cablevision. Another network was started in Japan. Nabu never achieved commercial success and ceased operation in 1985.

The heart of NABU (which stands for Natural Access to Bi-directional Utilities) was the Z80A processor chip (running at a 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, an N8X60N FIFO I/O controller and a pre-programmed ROM. The remainder of the parts on the board were numerous 74LS series logic ICs. There is 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.

The major weakness of this network was the strictly one-way connection as it was implemented on Ottawa Cable. 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.