The Portfolio can easily be overclocked from 4,9 MHz to 6,5 MHz by simply replacing the Quarz. You just have to make sure you have the "HC49U-S" variant, or else it won't fit in the case.

MHZ.COM for measuring the CPU clock: https://drive.google.com/open?id=1BKg_wzjhz850f3bD-sEQpR7G_9geLAfY

German version: https://makertube.net/w/dqUCVZh9u15UDuQMKLnQ6G

Epic Unease by Kevin MacLeod is licensed under "Creative Commons Attribution" (https://creativecommons.org/licenses/by/4.0/) Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100406 Artist: http://incompetech.com/