Sep 27

Twenty years after

I just shipped what was probably the silliest and most pointless software release of my career. But hey, it’s the reference implementation of a language and I’m funny that way.

Because I write compilers for fun, I have a standing offer out to reimplement any weird old language for which I am sent a sufficiently detailed softcopy spec. (I had to specify softcopy because scanning and typo-correcting hardcopy is too much work.)

In the quarter-century this offer has been active, I have (re) implemented at least the following: INTERCAL, Michigan Algorithmic Decoder, and a pair of obscure 1960s teaching languages called CORC and CUPL, and an obscure computer-aided-instruction language called Pilot.

Pilot…that one was special. Not in a good way, alas. I don’t know where I bumped into a friend of the language’s implementor, but it was in 1991 when he had just succeeded in getting IEEE to issue a standard for it – IEEE Std 1154-1991. He gave me a copy of the standard.

I should have been clued in by the fact that he also gave me an errata sheet not much shorter than the standard. But the full horror did not come home to me until I sat down and had a good look at both documents – and, friends, PILOT’s design was exceeded in awfulness only by the sloppiness and vagueness of its standard. Even after the corrections.

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Sep 24

Dilemmatizing the NRA

So, the Washington Post publishes yet another bullshit article on gun policy.

In this one, the NRA is charged with racism because it doesn’t leap to defend the right of black men to bear arms without incurring a lethal level of police suspicion.

In a previous blog post, I considered some relevant numbers. At 12% of the population blacks commit 50% of violent index crimes. If you restrict to males in the age range that concentrates criminal behavior, the numbers work out to a black suspect being a a more likely homicidal threat to cops and public safety by at least 26:1.

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Sep 18

Thinking like a master programmer, redux

Yes, there was a bug in my vint64 encapsulation commit. I will neither confirm nor deny any conjecture that I left it in there deliberately to see who would be sharp enough to spot it. I will however note that it is a perfect tutorial example for how you should spot bugs, and why revisions with a simple and provable relationship to their ancestors are best

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Sep 17

Thinking like a master programmer

To do large code changes correctly, factor them into a series of smaller steps such that each revision has a well-defined and provable relationship to the last.

(This is the closest I’ve ever come to a 1-sentence answer to the question “How the fsck do you manage to code with such ridiculously high speed and low defect frequency? I was asked this yet again recently, and trying to translate the general principle into actionable advice has been on my mind. I have two particular NTPsec contributors in mind…)

So here’s a case study, and maybe your chance to catch me in a mistake.

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Sep 13

Trials of the Beast

This last week has not been kind to the Great Beast of Malvern. Serenity is restored now, but there was drama and (at the last) some rather explosive humor.

For some time the Beast had been having occasional random flakeouts apparently related to the graphics card. My monitors would go black – machine still running but no video. Some consultation with my Beastly brains trust (Wendell Wilson, Phil Salkie, and John D. Bell) turned up a suitable replacement, a Radeon R360 R7 that was interesting because it can drive three displays (I presently drive two and aim to upgrade).

Last Friday I tried to upgrade to the new card. To say it went badly would be to wallow in understatement. While I was first physically plugging it in, I lost one of the big knurled screws that the Beast’s case uses for securing both cards and case, down behind the power supply. Couldn’t get it to come out of there.

Then I realized that the card needed a PCI-Express power tap and oh shit the card vendor hadn’t provided one.

Much frantic running around to local computer stores ensued, because I did not yet know that Wendell had thoughtfully tucked several spares of the right kind of cable behind the disk drive bays when he built the Beast. Which turns out to matter because though the PCI-E end is standardized, the power supply end is not and they have vendor-idiosyncratic plugs.

Eventually I gave up and tried to put the old card back in. And that’s when the real fun began. I broke the retaining toggle on the graphics card’s slot while trying to haggle the new card out. When I tried to boot the machine with the old card plugged back in, my external UPS squealed – and then nothing. No on-board lights, no post beep, no sign of life at all. I knew what that meant; evidently either the internal PSU or the mobo was roached.

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