Hacker News: theodorethomas

New comment by theodorethomas in "Celebrating 70 Years of Fortran"

theodorethomas — Fri, 16 Oct 2026 14:49:49 +0000

You know, I have read this a lot. But the Programmer's Reference Manual, dated October 15, 1956 clearly has it as Fᴏʀᴛʀᴀɴ, which used "small caps", so I am not so sure anymore.

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New comment by theodorethomas in "Celebrating 70 Years of Fortran"

theodorethomas — Fri, 16 Oct 2026 13:56:41 +0000

There is one under-appreciated aspect of Fortran.

Here is something that started as a specification of the input format of one particular program-tool. That input format was then cloned and mutated by dozens of me-too program-tools. Eventually that format was able to support an interpretation as a language with its own language-like abstractions. That is astonishing and I think was not on the radar of computing machinery people in the 50s.

New comment by theodorethomas in "Celebrating 70 Years of Fortran"

theodorethomas — Fri, 16 Oct 2026 09:59:51 +0000

many such cases

New comment by theodorethomas in "Icy Moons Are Ocean Worlds"

theodorethomas — Tue, 08 Sep 2026 12:44:53 +0000

I object to this mis-use of the word "ocean". If I can't sail there then it's not an ocean. Luckily, Titan still has an ocean. But all the others have iceans.

New comment by theodorethomas in "How bicycle coaster brakes work (2018)"

theodorethomas — Wed, 02 Sep 2026 16:17:27 +0000

Yes, this is how I used the "handbrake" function to "park" on a steep uphill.

New comment by theodorethomas in "Turns are Better than Radians (2022)"

theodorethomas — Thu, 20 Aug 2026 09:52:03 +0000

The Fortran 2023 Standard introduces new intrinsics:

"The intrinsic functions ACOSPI, ASINPI, ATANPI, ATAN2PI, COSPI, SINPI, and TANPI are trigonometric functions in which angles are specified in halfrevolutions (that is, as multiples of π)."

New comment by theodorethomas in "LEDs’ potential to save our night skies"

theodorethomas — Mon, 20 Jul 2026 14:47:52 +0000

I wondered if a city-wide synchronised Pulse-Width-Modulation of LED lights could allow astrophotography (or even naked-eye astronomy) to be possible again, with a filter synchronised to the off-cycle.

New comment by theodorethomas in "Ada, its design, and the language that built the languages"

theodorethomas — Fri, 17 Apr 2026 13:59:07 +0000

Reading the Steelman document is like reading a shopping list of everything that's gone into modern Fortran.

New comment by theodorethomas in "All elementary functions from a single binary operator"

theodorethomas — Mon, 13 Apr 2026 16:37:12 +0000

I wonder how this combines with Richardson's Theorem.

New comment by theodorethomas in "Intel 486 CPU announced April 10, 1989"

theodorethomas — Fri, 10 Apr 2026 15:19:07 +0000

Except the 486 had hardware floating point, essential for technical work.

New comment by theodorethomas in "Intel 486 CPU announced April 10, 1989"

theodorethomas — Fri, 10 Apr 2026 13:53:08 +0000

The 486 and https://www.delorie.com/djgpp/history.html changed everything.

Suddenly, it was possible to imagine running advanced software on a PC, and not have to spend 25,000 USD on a workstation.

New comment by theodorethomas in "Lunar Flyby"

theodorethomas — Wed, 08 Apr 2026 10:02:13 +0000

One consequence of that is that the Earth, as seen from the nearside of the Moon's surface, just hangs there, never moving, apart from a small wobble.

New comment by theodorethomas in "Why so many control rooms were seafoam green (2025)"

theodorethomas — Fri, 27 Mar 2026 12:21:56 +0000

Apollo Command Module interior colour is similar, and gorgeous.

New comment by theodorethomas in "What came after the 486?"

theodorethomas — Thu, 26 Mar 2026 13:40:58 +0000

I remember a 120MHz Pentium Linux box arriving at a cottage in Crete, where, with the aid of a 56k USRobotics modem, we (my wife and I) worked remotely in 1995-6. She had a Mac SE/30 for her tourist guidebook work. She later upgraded to a 6100 PowerMac "pizza-box", various iMacs, G3/G4/G5, whereas I saved a quad-200MHz PentiumPro monster (Compaq Professional Workstation 8000, tricked up to 3GB RAM) from the skip. I regret taking that to the recycling centre many years later.

New comment by theodorethomas in "Nobody gets promoted for simplicity"

theodorethomas — Wed, 04 Mar 2026 15:14:22 +0000

There are two ways of constructing software: one way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult.

— C. A. R. Hoare

New comment by theodorethomas in "What to Do When the Trisector Comes (1983) [pdf]"

theodorethomas — Tue, 06 Jan 2026 15:12:14 +0000

The sheer amount of dedication is awe-inspiring. In the 80s, at Imperial College, London, Theoretical Physics Group, we came across some correspondence intended for one of the professors, I think. This person had evidently "translated" his native Spanish into English, laboriously, via some dictionary we thought. We spent many tea breaks puzzling over phrases such as

"Is well-knew the refran: of the said to made it has a good road."

New comment by theodorethomas in "Fortran Outsmarted Our Billion-Dollar AI Chips"

theodorethomas — Wed, 19 Nov 2025 16:25:07 +0000

"The language assumes contiguous memory, column-major order, and no hidden aliasing between arrays."

One out of three ain't bad.

"Column-major order", that's the one. That just says that there is an implied order of elements of an array. This enables efficient mapping of an array of the language definition to storage with a linear address space. It does not require storage to be organised in any particular way.

"Contiguous memory". Not really, the language definition does not even use the word "memory". The language is carefully defined so that you can implement it efficiently on a linear address space in the presence of caches (no accident that IBM machines in the 80s were pushing caches while CRAY was pushing vector processors). The term "contiguous" in the language definition just means a collection whose parts are not separated by other data objects.

"no hidden aliasing between arrays". This is a crude mis-statement of the actual rule of argument association across subroutine/function caller-callee boundary. The rule takes pages to describe fully. A language that still has EQUIVALENCE statement (although marked obsolete) cannot be said to disallow aliasing. It is still quite hard to find a compiler that will reliably diagnose inadvertent aliasing at runtime. The actual rule in Fortran says something like "thou shall not cause any effect on (dummy name) A through a reference to some other name, unless (some-clause-x or y or z)".

New comment by theodorethomas in "John Carmack on mutable variables"

theodorethomas — Fri, 31 Oct 2025 12:24:27 +0000

Do as much as you can in a spreadsheet, then start a new spreadsheet.

New comment by theodorethomas in "The Prehistory of Computing, Part II"

theodorethomas — Wed, 01 Oct 2025 16:53:21 +0000

Part I managed to miss the Antikythera Mechanism.

New comment by theodorethomas in "Introducing tmux-rs"

theodorethomas — Wed, 09 Jul 2025 17:00:23 +0000

It is not suited to cases where the machine state is experienced by the user at all times (games, hardware-control, real-time transactions). It is very suited to cases where the machine is expected to act like a SSBN, disappearing from view until a large floating-point calculation is ready.