3928731

Information

• Patent Grant
• 3928731

• References
• Source

• Patent Number

  3,928,731

• Date Filed

  Not available

• Date Issued

  Tuesday, December 23, 1975
  49 years ago

• CPC

  • H04M1/276 - using magnetic recording

• US Classifications

  • 379 - Telephonic communications
  • 360 - Dynamic magnetic information storage or retrieval