Two scary signs that a site is unsafe

Sep 26, 2015 • Marco Cecconi

I generate random passwords of 24 characters chosen from a wide variety when registering to sites. I then use a password manager to remember the password, because of course it would be impossible to remember these. This allows me to browse with a little more security, and it also has the intended s…

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A computer from scratch - ADDing more functionality

Sep 12, 2015 • Marco Cecconi

In the first installment of "A computer from scratch", I've built a NAND gate. In the third part I've built NOT, AND and OR circuits and I've also introduced the 4011 CMOS NAND gates, which I'm using instead of a bunch hand built, transistor-based NANDs (because hey, that's a lot of wiring, but not …

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Data Structures for Andela: Iterators (part 2)

Aug 31, 2015 • Marco Cecconi

As part of Stack Overflow's pro-diversity initiatives, I have been helping Andela by mentoring one of their fellows, Bosun, in data structures and algorithms. In the Stack Overflow "default open" style, I am putting some of our notes on the internet, in the hope they will be useful to more people. M…

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Announcing z80, my Zilog z80 emulator

Aug 13, 2015 • Marco Cecconi

The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes. The Z80 and its derivatives and clones made up one of the most commonly used CPU families of all time, and, a…

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A computer from scratch - Fish and chips

Aug 10, 2015 • Marco Cecconi

In the first installment of "A computer from scratch", I've built a NAND gate. I've also introduced the my "scaling" rule: if I build something, I can buy it pre-made, because I only have one lifetime to spend on this :-) Therefore. I've bought a bunch of 4011 CMOS NAND gates, here they are: And…

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Data Structures for Andela: Iterators (part 1)

Aug 05, 2015 • Marco Cecconi

As part of Stack Overflow's pro-diversity initiatives, I have been helping Andela by mentoring one of their fellows, Bosun, in data structures and algorithms. In the Stack Overflow "default open" style, I am putting some of our notes on the internet, in the hope they will be useful to more people. M…

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The one mistake that ultimately destroys modern companies

Jul 31, 2015 • Marco Cecconi

Openly inspired by a nice talk by Joel Spolsky London, 1850. Let's say you are the owner of a factory that produces nails and bolts. Workers use huge, expensive machinery in a large factory. Machinery is so expensive you needed a lot of money to buy it, so it's paramount to use it as much as poss…

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A computer from scratch - NANDing all the way

Jul 26, 2015 • Marco Cecconi

A technical side note to my first "A computer from scratch" post and In preparation for the next step, I've examined whether it's possible to build any gate from NANDs. Is it possible? YES! Let's prove it, mathematically. Theorem Any truth table can be built by combining NANDs. Lemma 1 Any t…

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A computer from scratch - Eating at NANDos

Jul 20, 2015 • Marco Cecconi

I am attempting to build a computer from prime principles. Am I crazy? Probably. But I have a plan. Let's start from the beginning Why, oh why? Because not knowing how stuff works bugs me to no end. It's not enough for me to use a programming language. In the past I dabbled and spent more than …

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My talks this year

Jun 24, 2015 • Marco Cecconi

There are three conferences I'll be speaking at this year. I'm seriously trying to do as few conferences as possible, but I really wanted to speak at these. If you'd like to chat about code and development, drink a beer or eat a pizza: I'm game. Here's the amazing 3: jDay my bio page JDay is one…

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A software engineer & Stack Overflow alumnus in London. I write about software development, coding, architecture and team leadership. I also speak at conferences worldwide.

About me

Gleanings

Performance bugs - the dark matter of programming bugs
Nicholas Chapman • Mar 22, 2017

A performance bug is one where the code is slower than the simple, textbook solution of the problem, due to performing redundant or unnecessary work, or choosing the wrong algorithm, or a logic error.

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