Bulletins from the Pacific Packet Radio Society - page 119

a possible dedicated packet radio mission a few years from now.

The demonstration QSO took place just one week after a landmark meeting held under AMSAT's auspices to establish and coordinate common packet radio protocols. This meeting in the Washington, DC a re a was attended by representatives of packet radio groups from San Francisco, Tucson, St. Louis, Washington and New Jersey. The meeting succeeded in reconciling minor differences that had evolved between the various groups during their R&D activities. The goal of establishing common protocols was focused on the upcoming satellite launches when it will be possible, for the first time, for the different packet radio groups to reliably inter-connect local networks on a global basis.

During the long-haul test, both N5AHD and W3IWI were using special 8085 microprocessor based Terminal Node Controller (TNC) hardware developed in Canada by the Vancouver Area Digital Group (VADG), with software developed in Vancouver, San Francisco and Washington. They both used conventional 11202A" FSK modems operating thru 100 watt SSB transceivers. A number of packets were successfully exchanged in both directions and the TNC board's software automatically verified the accuracy of each transmission. The HDLC protocol dictates that if any error is detected, the transmitting station re-tries until an error-free copy is received. In the test QSO, the number of re-tries required never exceeded three. The stations had conducted previous long-haul test experiments through the AMSAT-OSCAR-8 satellite.

W3IWI has been involved in a number of previous AMSAT demonstration tests including initial feasibility demonstrations using satellites to locate downed aircraft which led to the international Search-and-Rescue Satellite (SARSAT) program and tests of digital phase-shift keying (PSK) techniques to be employed on the Phase 3 satellite series. N5AHD has developed automated, real time telemetry acquisition techniques for the UOSAT-OSCAR 9 satellite and operates AMSAT's Computer Bulletin Board System (CBBS) which can be accessed at (512) 852-8194. Both N5AHD and W3IWI have been frequent contributors of amateur radio software which is available through the AMSAT Software Exchange (ASE). Further information about AMSAT, ASE or AMSAT's CBBS can be obtained by calling the CBBS or by writing:

AMSAT
Box 27
Washington, DC 20044

FILE QST.82.10.21.0.VE7ADE

To All PRNET,

It has just been pointed out to me that my rendition of the VADCG parts order form is very confusing. The IRS232 parts kit' contains everything required to populate a board, including PROM, RAM, 8250, 8273, connectors, sockets, etc. There is 4k ROM and

Click for Original Graphic Image of this page.