Historical Document · 1978
US Patent 4,109,315: Wristwatch Calculator with Selectively Scanned Keyboard (Hewlett-Packard)
HP-01 keyboard scanning patent: filed 30 August 1976, granted 22 August 1978.
Historical Document · 1978
HP-01 keyboard scanning patent: filed 30 August 1976, granted 22 August 1978.