You can find Ken on Twitter at twitter.com/kenshirriff and his blog righto.com.

- Soyuz blog post:

    http://www.righto.com/2020/01/inside-digital-clock-from-soyuz.html

- IBM System/370: https://en.wikipedia.org/wiki/IBM_System/370

- Amdahl: https://en.wikipedia.org/wiki/Amdahl_Corporation

- Build Your Own Z80 Computer:

    https://books.google.com/books?id=mVQnFgWzX0AC&pg=PA1#v=onepage&q&f=false

- Euler: https://en.wikipedia.org/wiki/Leonhard_Euler

- Commodore PET: https://en.wikipedia.org/wiki/Commodore_PET

- TRS-80 (Trash-80): https://en.wikipedia.org/wiki/TRS-80 https://techland.time.com/2012/08/03/trs-80/

- Visual 6502: http://www.visual6502.org/

- MOS 6502: https://en.wikipedia.org/wiki/MOS_Technology_6502

- Metallurgy microscope: https://www.amscope.com/compound-microscopes/metallurgical-microscopes.html

- AM2900: https://en.wikipedia.org/wiki/AMD_Am2900

- MOS transistor: https://en.wikipedia.org/wiki/MOSFET

- Cray-1: https://en.wikipedia.org/wiki/Cray-1

- Intel 4004: https://en.wikipedia.org/wiki/Intel_4004

- Datapoint 2200: https://en.wikipedia.org/wiki/Datapoint_2200

- Intel 8008: https://en.wikipedia.org/wiki/Intel_8008

- Endianness: https://en.wikipedia.org/wiki/Endianness

- TTL chips: https://en.wikipedia.org/wiki/Transistor%E2%80%93transistor_logic

- Big Endian and Little Endian:

    https://chortle.ccsu.edu/AssemblyTutorial/Chapter-15/ass15_3.html

- Xerox Alto: https://en.wikipedia.org/wiki/Xerox_Alto

- Charles Simonyi: https://en.wikipedia.org/wiki/Charles_Simonyi

- Punched cards: https://en.wikipedia.org/wiki/Punched_card

- Why did line printers have 132 columns?:

    https://retrocomputing.stackexchange.com/questions/7838/why-did-line-printers-have-132-columns

- Teletype 33: https://en.wikipedia.org/wiki/Teletype_Model_33

- Analogue computer: https://en.wikipedia.org/wiki/Analog_computer

- Analogue computer thread: https://twitter.com/kenshirriff/status/1223675683387265024

- Differential analyser: https://en.wikipedia.org/wiki/Differential_analyser

- Bitcoin mining on a 1401:

    http://www.righto.com/2015/05/bitcoin-mining-on-55-year-old-ibm-1401.html

- Mining bitcoin with pencil and paper: https://www.youtube.com/watch?v=y3dqhixzGVo

- Bitcoin mining on a Xerox Alto:

    http://www.righto.com/2017/07/bitcoin-mining-on-vintage-xerox-alto.html

- Bitcoin mining on the Apollo Guidance computer:

    http://www.righto.com/2019/07/bitcoin-mining-on-apollo-guidance.html

- Colossus computer: https://en.wikipedia.org/wiki/Colossus_computer

- Accounting machine: https://en.wikipedia.org/wiki/Accounting_machine

- Memory phosphor: https://www.britannica.com/science/memory-phosphor

- Rowhammer: https://en.wikipedia.org/wiki/Row_hammer

- Core memory: https://en.wikipedia.org/wiki/Magnetic-core_memory

- Williams tube: https://en.wikipedia.org/wiki/Williams_tube

- Core rope memory: https://en.wikipedia.org/wiki/Core_rope_memory

- Honeywell 800: https://people.cs.clemson.edu/~mark/h800.html

- Honeywell 1800: https://www.computerhistory.org/brochures/doc-4372956da1170/

    http://ed-thelen.org/comp-hist/BRL64-h.html#HONEYWELL-1800

- SPARC delayed branching:

    https://arcb.csc.ncsu.edu/~mueller/codeopt/codeopt00/notes/delaybra.html

- IBM 360 Model 50: https://en.wikipedia.org/wiki/IBM_System/360_Model_50

- RR Auction: https://www.rrauction.com/