Method and apparatus for synchronizing the readout of a sequential media device with a separate clocked device

Apparatus for controlling the readout rate of information from a sequential storage medium, comprising:

• a buffer for loading information from the sequential device,
• write and read address registers for loading and unloading information to and from the buffer in a circular fashion,
• a clock for controlling the rate of loading information into the buffer,
• first means activated by a write of information into the buffer for storing the most significant bit of the buffer write address,
• second means activated by a read of information from the buffer for storing the most significant bit of the buffer read address,
• third means responsive to the first and second storing means for storing a signal once on each pass, selected from a write or a read pass, through the buffer indicating whether the buffer is greater than half full, and
• means responsive to the said stored signal for adjusting the rate of the clock to maintain the amount of free buffer space within predetermined limits.

Apparatus for controlling the readout rate of information from a sequential storage medium, comprising:

• a buffer for loading information from the sequential device,
• write and read address registers for loading and unloading information to and from the buffer in a circular fashion,
• a clock for controlling the rate of loading information into the buffer,
• first means activated by a write of information into the buffer for storing the most significant bit of the buffer write address,
• second means activated by a read of information from the buffer for storing the most significant bit of the buffer read address,
• third means responsive to the first and second storing means for storing a signal once on each pass, selected from a write pass or a read pass, through the buffer indicating whether the buffer is less than half full, and
• means responsive to the said stored signal for adjusting the rate of the clock to maintain the amount of free buffer space within predetermined limits.