NABU Network

For other uses, see Nabu (disambiguation).

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, Canada. 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, approximately the same price as the wildly successful Commodore 64 at the time, and the network service cost $8 to $10 per month.[1]

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

References

• IEEE Canada page describing NABU project
• YUCoM NABU Reconstruction Project
• Jim Ducharme, The Nabu Network, PC World, December 4 2005. Archived at York University YUCoM.

External links

• Hardware Photos
• Play Nabu Game Online