By Walter S. Ciciora And William L. Thomas, American Television & Communications Corporation
The first videotex alternative determines whether the transmission is broadcast, telephone, or cable. The concentration here is on cable. The reasons for this will be discussed in detail since they are fundamental to understanding cable's substantial advantages over competing media. In cable there are a wide variety of alternatives to consider. Should the videotex service be vertical blanking interval or full field? Will financial support come from advertising or from pay, or both? If a pay structure is chosen will the security be soft, firm or hard? Will the service be tiered and addressable or simply go no-go? Will it be one-way, one-way upgradable, or two-way? Will the display be RF or RGB? Are mosaic graphics adequate, or must geometric graphics be employeed from the very beginning? Plain or fancy?