You can find John on Twitter at [twitter.com/jgrahamc](https://twitter.com/jgrahamc).

- Babbage overview and the Difference Engine:

    https://www.computerhistory.org/babbage/overview/

- Difference Engine No. 2 at the London Science Museum:

    https://collection.sciencemuseumgroup.org.uk/objects/co526657/difference-engine-no-2-designed-by-charles-babbage-built-by-science-museum-difference-engine

- BBC Micro: https://en.wikipedia.org/wiki/BBC_Micro

- Sinclair ZX81: https://en.wikipedia.org/wiki/ZX81

- BBC Micro Advanced User Guide:

    http://stardot.org.uk/mirrors/www.bbcdocs.com/filebase/essentials/BBC%20Microcomputer%20Advanced%20User%20Guide.pdf

- Sharp MZ-80K: https://en.wikipedia.org/wiki/Sharp_MZ

- John's TED Talk, The greatest machine that never was: https://www.ted.com/talks/john_graham_cumming_the_greatest_machine_that_never_was

- Hilbert's Problems: https://mathworld.wolfram.com/HilbertsProblems.html

- Gödel's incompleteness theorems: https://plato.stanford.edu/entries/goedel-incompleteness/

- The Lovelace–De Morgan mathematical correspondence - A critical re-appraisal: https://www.sciencedirect.com/science/article/pii/S0315086017300319

- The mathematical correspondence of Ada Lovelace and Augustus De Morgan:

    https://dl.acm.org/doi/10.1145/2867731.2867738

- Douglas Engelbart: https://www.britannica.com/biography/Douglas-Engelbart

- "Mother of all demos": https://www.youtube.com/watch?v=yJDv-zdhzMY

- John's OSCON talk "Turing's Curse": https://www.youtube.com/watch?v=hVZxkFAIziA

- Design of the RISC-V Instruction Set Architecture:

    https://people.eecs.berkeley.edu/~krste/papers/EECS-2016-1.pdf

- Engines of Creation - The Coming Era of Nanotechnology: https://www.amazon.com/Engines-Creation-Nanotechnology-Scientific-Revolution/dp/1872180469/ref=tmm_hrd_swatch_0?_encoding=UTF8&qid=&sr=