Standard/nonstandard internal vertical sync producing apparatus

摘要

Apparatus for producing internal vertical sync signals from a source of standard and nonstandard rate external vertical signals. The apparatus includes a counting and reset arrangement for generating internal vertical sync signals in synchronization with the external vertical signals when the external signals are occurring at a standard rate. A nonstandard signal sampling arrangement causes the generation of the internal vertical sync signals in synchronization with the external signals at a nonstandard rate after a predetermined time in which these nonstandard signals occur. Still other circuit elements generate standard rate internal vertical sync signals during the predetermined time in which these nonstandard rate signals occur.