If you want a truly native option, a small run of HP-15C calculators was manufactured a year or two ago and you can still get them: https://hpcalcs.com/product

If you want a truly native option, a small run of HP-15C calculators was manufactured a year or two ago and you can still get them: https://hpcalcs.com/product/hp-15c-collectors-edition/ https://hpcalcs.com/product/hp-15c-collectors-edition/ I bought one and am happy every time I use it, which is quite often.