The NC-77 was a miracle, but a used PalmIII for $25 and some nav software for $20 more becomes much easier to FIND. More versatile, easier to replace or carry a spare, too. John Manson's Pilot Navigator Software - Handheld Software for Pilots & Sailors
strongly recommended, he's a very accommodating and responsive author/vendor as well.
My old Palm IIIe may get used again.