Categoría: cacharritos

Byte, octubre del 85

Portada de la revista Byte de octubre de 1985. El tema de portada es Simulating Socienty. Lo ilustra una hoja de papel de impresora que envuelve unas caras humanas.

Vamos allá con nuestra relectura de lo último en informática…de hace cuarenta años, a través de los archivos de la revista Byte en archive.org. Hoy toca octubre de 1985.

Para comenzar, no os quejéis de que no estáis presenciando los grandes avances de la historia. Os presento… ¡el disquete de alta densidad! (Creo que la mayoría de los que me leéis ya sois talluditos y apreciaréis que saltar de 720 kilobytes a 1.44 megas, sin ser revolucionario, sí fue todo un salto.)

Sony, Toshiba Prepare High-Density 3 ½ inch Disks Sony announced in Tokyo that it has developed a 2-megabyte 3½ inch floppy disk, storing 1.6 megabytes (formatted) by doubling the number of sectors per track. The 2-megabyte medium uses a 1 micron magnetic layer (half the thickness of current 1 -megabyte disks) and requires a higher coercivity (700 rather than 600-620 oersteds). While the 2-megabyte versions use the same magnetic technology as earlier 3 ½-inch disks and drives, the magnetic heads of the drives require higher tolerances. An additional disk cartridge hole allows drives to distinguish between 1- and 2-megabyte disks. Although it has already licensed 38 companies to produce 2-megabyte disks, Sony says it is waiting for formal standards to be set before marketing the disks and drives, which should be available to OEMs next year, probably at prices about 20 percent higher than 1-megabyte versions. An even denser 3 ½-inch drive from Toshiba uses perpendicular recording technology to squeeze 4 megabytes of data onto a single-sided disk coated with barium ferrite. Toshiba plans to release evaluation units early next year, with full production slated for 1987 While the 2-megabyte versions use the same magnetic technology as earlier 3 '/2-inch disks and drives, the magnetic heads of the drives require higher tolerances. An additional disk cartridge hole allows drives to distinguish between 1- and 2-megabyte disks. Although it has already licensed 38 companies to produce 2-megabyte disks, Sony says it is waiting for formal standards to be set before marketing the disks and drives, which should be available to OEMs next year, probably at prices about 20 percent higher than I -megabyte versions. An even denser 3 '/2-inch drive from Toshiba uses perpendicular recording technology to squeeze 4 megabytes of data onto a single-sided disk coated with barium ferrite. Toshiba plans to release evaluation units early next year, with full production slated for 1987.

Que levante la mano quien supiese / recordase que antes de Access, la base de datos de Microsoft (que no llegaría hasta 1992), hubo un Microsoft Access para conectarse a servicios de información a través del módem (yo no tenía ni idea / no lo recordaba en absoluto). La hegemonía del Access base de datos es tal que apenas he sido capaz de encontrar más información al respecto.

Anuncio de Microsoft Access. Lo ilustra un ordenador sobre el que hay el auricular de un teléfono de sobremesa, roto por la mitad. El titular es Don't get mad, get Access

En nuestra habitual sección «crees que esto se acaba de inventar, pero no» tenemos a la sección de libros, que se hace eco de Computer culture : the scientific, intellectual, and social impact of the computer, disponible, como no, en archive.org, que recogía las ponencias de la conferencia del mismo nombre, porque no es solo en Despacho 42 que nos preocupamos de estos temas y que, naturalmente, ya se preocupaba del impacto de la IA…

Artificial Intelligence Approximately one-fourth of Computer Culture (four papers and one panel discussion) deals specifically with artificial intelligence. The panel discussion on the impact of Al research is the most thought-provoking contribution in the book. As you might expect, this discussion is not so concise as an article dealing with the same topic, but the interaction among the panel members is intriguing. The panel consists of two philosophers (Hubert Dreyfus and John Searle) and three computer scientists (John McCarthy, Marvin Minsky, and Seymour Papert). Much of the discussion is spent identifying important questions about Al. Each panelist has a distinct viewpoint, resulting in a diversity of questions. Among these, however, two issues are of overriding concern: Can machines think? If they can, is machine thinking the same as human thinking? The panelists seem to agree that computers can be used to study thinking, if for no other reason than to provide a contrast with human thought processes. On the other hand, the suggestion that appropriately programmed computers could duplicate human thought processes is much more controversial. Aside from the philosophical issues, Papert makes a very important point when he argues that it is dangerous to reassure people that machines will never be able to challenge the intellectual capabilities of human beings. If people are lulled into a sense of security about machine capabilities, they will be ill prepared to deal with situations in which machines become better than people at doing specific jobs, he says. Whether or not the machines are described as thinking in these situations, the social and psychological issues raised by machine capabilities demand attention.
(Enlazo a la página de portada de la sección de libros, en vez de la específica del fragmento que tenéis aquí. En cualquier caso, vale la pena leer la crítica completa… e incluso el libro, si tenéis la oporunidad)

Más cosas que no se inventaron ayer. Uno ve poco fútbol del de darle patadas a un balón, pero bastante fútbol americano, un deporte en que las retransmisiones no serían lo mismo sin la obligatoria skycam, ua cámara que sobrevuela el terreno de juego colagada de cuatro cables. Y sí, cumple cuarenta años:

Skycam: An Aerial Robotic Camera System A microcomputer provides the control to add three-dimensional mobility to TV and motion picture cameras On a morning in March 1983, a group of technicians gathered at Haverford High School in a suburb of Philadelphia. Each brought an electrical, mechanical, or software component for a revolutionary new camera system named Skycam (see photo 1). Skycam is a suspended, mobile, remote-controlled system designed to bring three-dimensional mobility to motion picture and television camera operation. (See the text box on page 128.) I used an Osborne 1 to develop Skycam's control program in my basement, and it took me eight months of evenings and weekends. As of 3 a.m. that morning, however, the main control loop refused to run. But 19 hours later, Skycam lurched around the field for about 15 minutes before quitting for good. Sitting up in the darkness of the press booth, hunched over the tiny 5-inch screen, 1 could see that the Osborne 1 was not fast enough to fly the Skycam smoothly. In San Diego 18 months later, another group of technicians opened 20 matched shipping cases and began to get the Skycam ready for an NFL preseason game between the San Diego Chargers and the San Francisco FortyNiners. The Skycam was now being run by an MC68000 microprocessor based Sage computer, and a host of other improvements had been made on the original. [Editor's note: The Sage Computer is now known as the Stride: however, the machine used by the author was purchased before the company's name change. For the purpose of the article, the machine will be referred to as the Sage.] For the next three hours, Skycam moved high over the field fascinating the fans in the stadium while giving the nationwide prime-time TV audience their first look at a new dimension in sports coverage. Skycam represents an innovative use of microcomputers. The portable processing power needed to make Skycam fly was unavailable even five years ago. That power is the "invention" upon which the Skycam patents are based. It involves the support and free movement of an object in a large volume of space. The development team used the following experiment to test the movement and operation of the Skycam. At a football field with one lighting tower at each of four corners, the team members bolted a pulley to the top of each pole, facing inward. Then they used four motorized winches, each with 500 feet of thin steel cable on a revolving drum and put one at the base of each tower. Next, they ran a cable from each motor to the top of its tower and threaded the cable through the pulley. They pulled all four cables from the tops of the towers out to the middle of the field and attached the cables to a metal ring 2 feet in diameter weighing 10 pounds (see figure 1). A motor operator was stationed at each winch with a control box that enabled the operator to slowly reel in or let out the cable. Each motor operator reeled the cable until the ring was suspended a few feet from the ground, and then they were ready to demonstrate Skycam dynamics. All four motor operators reeled in the cable. The ring moved upward quickly. If all four motors reel in at the same rate (and the layout of lighting towers is reasonably symmetrical) the ring will move straight up. In the experiment, the two motors on the left reeled in and the two on the right reeled out. The ring moved to the left and maintained its altitude. An instruction was given to the two motor operators on the left to reel out and the two on the right to reel in just a little bit. The ring moved right and descended as it moved back toward the center. The theoretical basis of this demonstration is quite simple. For each point in the volume of space bounded by the field, the four towers and the plane of the pulleys, there is a unique set of four numbers that represents the distances between that point and each of the four pulley positions. Following the layout above for an arbitrary point on the field, you can...

Pero este mes me quedo con el tema de portada: el uso de simulaciones informáticas para modelar la sociedad:

Simulating Society THE NEED FOR GREATER RIGOR in the social sciences has long been acknowledged. This month's theme examines computer-based simulation as a means to achieving that end. Simulation may be able to assist in evaluating hypotheses, not in the sense that an experiment in the physical sciences can test a hypothesis, but in the sense of making plain the ramifications of a hypothesis. The value of specifying a hypothesis with sufficient clarity to be amenable to programming and of examining the consequences of that hypothesis should not be underestimated. Indeed, one of the interesting aspects of the work presented here is that these researchers appear to be developing a tool for the social sciences that is not simply a poor stepchild of physical science methodologies. Our first article, "Why Models Go Wrong" by Tom Houston, is a wonderfully readable account of the ways that you can misuse statistics. Next, Wallace Larimore and Raman Mehra's "The Problem of Overfitting Data" discusses a difficult but important topic. Overfitting happens when your curve traces the noise as well as the information in your data. The result is that the predictive value of the curve actually deteriorates. In "Testing Large-Scale Simulations," Otis Bryan and Michael Natrella show how validation (determining whether the specification for the simulation corresponds with reality) and verification (determining whether the simulation program corresponds with the specification) were achieved on a large-scale combat simulation they developed for the Air Force. The ways of economic modeling are illustrated by Ross Miller and Alexander Kelso, who show how they analyzed the effects of proposed taxes for funding the EPA Superfund in "Analyzing Government Policies." Michael Ward discusses his ongoing research in simulating the U.S.-Soviet arms race in "Simulating the Arms Race." Several authors discuss new and surprising applications of simulation. In "EPIAID," Dr. Andrew Dean describes the development of computer-based aids for Centers for Disease Control field epidemiologists. Royer Cook explains how he fine-tuned a model in "Predicting Arson," and Bruce Dillenbeck, who uses an arson-prediction program in his work as a community activist, discusses modeling in "Fighting Fire with Technology" Articles in other sections of the magazine that relate to this theme include Zaven Karian's review of GPSS/PC and Arthur Hansen's Programming Insight "Simulating the Normal Distribution." When I began researching this theme, I took an excellent intensive course in simulation from Edward Russell of CACI. Dr. Russell's is the unseen hand guiding the development of this theme. Of course, any blame for bias in the choice of theme topics belongs to me, but much of the credit for the quality that is here must reside with him.

No os perdáis los artículos sobre los problemas, comenzando por los dos que abren la sección, sobre los riesgos del mal modelado (un tema que, desafortunadamente, tiene hoy todavía más importancia que hace cuarenta años), y siguiendo con el de modelado económico con Lotus 1-2-3, o el de epidemiología.

Ah, y aprovechando que la cosa iba de modelado… ¿sabíais que SPSS/PC+, no solo ya existía en 1985, sino que fue lanzado en 1968? Si a alguien se le ocurre un software que lleve más tiempo en el mercado, que avise.

Anuncio del programa SPSS/PC+. El eslogan es Make Stat Magic. Lo ilustra la foto de un sombrero de copa, como los de los magos, del que sale un disquete de 5¼ etiquetado SPSS/PC+

Y no vamos a dejar de hablar del Amiga, claro. Esta vez, es Bruce Webster, otro de los columnistas estrella de la revista, el que nos explica lo mucho que ha alucinado con la potencia, el precio y la elegancia del sistema:

According to Webster Commodore's Coup Product of the Month: Amiga Last month, I made a few comments about the future of the home computer market, based on rumors I had heard about the Amiga from Commodore. In essence, I said that if what I had heard was true the Amiga might be the heir to the Apple II in the home/educational/small business marketplace. Since writing that. 1 have seen the Amiga. I have watched demonstrations of its abilities; I have played with it myself; and I have gone through the technical manuals. My reaction: I want to lock myself in a room with one (or maybe two) and spend the next year or so discovering just what this machine is capable of. To put it another way: I was astonished. Hearing a description of a machine is one thing, seeing it in action is something else especially where the Amiga is concerned I can tell you that the low-resolution mode is 320 by 200 pixels, with 32 colors available for each pixel (out of a selection of 4096). But that does not prepare you for just how stunning the colors are especially when they are properly designed and combined. It also doesn't tell you that you can redefine that set of 32 colors as the raster-scanning beam moves down the screen, letting you easily have several hundred colors on the screen simultaneously. It also doesn't tell you how blindingly fast the graphics hardware is. If you've seen some of Commodore's television commercials demonstrating the Amiga's capabilities, or if you've looked at the machine yourself, you have some idea as to what the machine can do. If you haven't, I'm not sure I can adequately describe it. Having seen the graphics on the Amiga, I have to smile when I hear people lump it together with the Atari 520ST. The high resolution mode on the ST is 640 by 400 pixels with 2 colors (out of 512); on the Amiga, it is 640 by 400 pixels with 16 colors (out of the 4096). and you can redefine those 16 colors as the raster-scanning beam goes down the screen. Also, the graphics hardware supporting all those colors is much faster. Little wonder, then, that a friend of mine, a game developer with several programs on the market, came back from the Amiga developers' seminar with plans to return the Atari ST development system at his house and to turn his attentions to the Amiga instead. As I guessed last month, the real strength of the Amiga is its totally open architecture. An 86-pin bus comes out of one side of the machine, giving any add-on hardware complete control of the machine What's more 512 K bytes of the 68000's 16-megabyte address space have been set aside for expansion hardware, 4K bytes each for 128 devices. A carefully designed protocol tells hardware manufacturers what data they should store in ROM (read-only memory) so that the Amiga can automatically configure itself when booted. This is a far cry from the closed-box mentality of the Macintosh, which has forced many hardware vendors through weird contortions just to get their devices to talk consistently to the Mac without crashing. The memory map is well thought out. The Amiga comes with 256K bytes of RAM (random-access read/write memory); an up...

Snif.

Si os lo leéis entero, por favor no os asustéis cuando lleguéis al momento en que comenta que la RAM está a 350 dólares (algo más de mil, actualizando la inflación) por 256 kilobytes. Vamos, que lo por lo que costaban 256 kilobytes hoy te puedes comprar unos 320.. gigabytes. Un millón a uno. (Y supongo que no os sorprenderá mucho comprobar que los márgenes de beneficio de Apple al vender RAM para sus sistemas no son una cosa del siglo XXI.)

Y lo dejamos aquí por este mes. Nos vemos el mes que viene, con el número de noviembre.

Byte, septiembre del 85. Diez años de Byte

Portada de Byte de septiembre de 1985. Un tema de portada es el 'homebrewing', el otro, el supersistema de Ciarcia, con un ordenador compatible con Z80 a 6 megahercios y con 256 kilobytes de RAM

Pues vamos allá con el número de septiembre del 85 de Byte, el del décimo aniversario de la revista… En portada, un ordenador, pero uno construido por uno de los autores estrella de la revista, Steve Ciarcia, que se sacaba de la manga un ordenador de 8 bits para la era de los 16, con todo lujo de esquemas para que te lo montaras tú mismo:

BUILD THE SB180 SINGLE-BOARD COMPUTER PART 1: THE HARDWARE by Steve Ciarcia This computer reasserts 8-bit computing in a 16-bit world Newer, faster, better. These words are screamed at you in ads and reviews of virtually every new computer that comes to market. Unfortunately, many of the proponents of this rhetoric are going on hearsay evidence. While advertising hype has its place in our culture, a more thorough investigation may lead you to alternative conclusions. Generally speaking, quotes of increased performance are basically comparisons of CPU (central processing unit) instruction times rarely involving the operating system. The 68000 is indeed a more capable processor than the 6502, but that doesn't necessarily mean that commercial application programs always run faster because the CPU has more capability. People owning 128K-byte Macintoshes have discovered this. The bus size of the processor is only one factor in the performance of a computer system. Operating-system design and programming styles contribute much more to the overall throughput of a computer. It is not enough to simply compare 8 to 16 bits or 16 to 32 bits. For example, the Sieve of Eratosthenes prime-number benchmark runs faster in BASIC on the 8-bit 8052-based controller board presented in last month's Circuit Cellar than it does on a 16-bit IBM PC.

Y por si esto no fuera suficiente para la sección «cosas que no veríamos en una revista generalista de informática hoy»…

AN ANALYSIS OF SORTS by Jonathan Amsterdam How to choose one sorting algorithm over another A friend told me recently that 90 percent of all the computer programs in the world sort. I can believe it. Our society's passion for organization has elevated the simple task of putting things in order to a position of major importance. And who better to carry out the job than those informational beasts of burden— computers? Because of their significance, sorting algorithms have been thoroughly studied. Some are slow and some are fast. Some sort a few items and some sort millions of items. Here I want to discuss sorting in the context of three different algorithms: Selection Sort, for small lists. Quicksort, for larger lists, and Mergesort, for lists of a size so monstrous they can't fit into memory all at once. But first we will need to develop some simple tools to help us with our analysis of these algorithms. Analysis Our goal is to understand the efficiency of some sorting algorithms. But we are immediately faced with a problem: How can we study an algorithm in the abstract without considering the language it's written in or the machine it's running on? For example, any algorithm written in a high-level language will run faster when written in assembly language. And any program running on a microcomputer would run faster on a mainframe. We want to abstract away from these facts, to talk about an algorithm's running time independent of machine or language.

Efectivamente: una discusión lo suficientemente sesuda como para una asignatura de Algoritmos de primero de carrera sobre los diferentes algoritmos de ordenación (temazo de lectura siempre muy recomendable), con sus grafiquitas sobre complejidades de tipo lineal, cuadrática y «n log n», algoritmos no tan básicos…

Figure 1: the rates of grouth of n, n log n and n squared Listing 1: The algorithm for Selection Sort. Selection Sort. Input: an array, A, and its size, n. Output: the same array A, in sorted order, begin for i : = 1 to n do begin m : = i; for j : = i + 1 to n do compare A[j] to A[m], making j the new m if it is less; swap A[i] and A[mj; end end.

…el merge sort (o ordenamiento por mezcla),

Figure 2. The mergesort treeListing 2. The algorithm for Mergesort. Mergesort. Input: a list, L. Output: a sorted list, S. begin If L is one item long, then S = L Otherwise, split L into two lists L1 and L2, each about half as big. Mergesort L1 into S1. Mergesort L2 into S2. merge S1 and S2 into S. end.

…o el mismísimo Quicksort:

Listing 3: The algorithm for Quicksort. Quicksort. Input: an array A, with items from 1 to n. Output; the same array, sorted, begin choose a pivot; partition the list so that all items < = pivot are < i; Quicksort A from 1 to i - 1 ; Quicksort A from i to n; end.

Pero la gracia de este número era la celebración del primer decenio de vida de la revista, y el consiguiente echar la vista atrás, entrevistas incluidas con el ya citado Ciarcia o Jerry Pournelle (de quin hablamos en el número de julio).

NO CELEBRATION of BYTE's 10th anniversary would be complete without the acknowledgment of some of the events and contributions that helped to shape the magazine. In the too-few pages that follow, we tried to capture some of the flavor of the past 10 years. Special thanks to all contributors and to the BYTE staff, especially Gregg Williams, who chaired the project, Richard Shuford, Rich Malloy, Mark Welch, and Stan Wszola. A Microcomputing Timeline Notable Quotes Evolution of the Microprocessor Interview: Carl Helmers Interview: Steve Ciarcia Ciarcia's Prodigious Output Interview: Robert Tinney Tinney Favorites Interview: Jerry Pournelle

Vale la pena ir siguiendo los enlaces a la revista que dejo en cada imagen, aunque solo sea para disfrutar de las maravillas del diseño industrial de la segunda mitad de la década de los setenta y la primera mitad de la de los ochenta…

Fotos de los ordenadores Sphere 1, Kim-1 y el Altair 8800, todos ellos de de 1975

…como el Sphere 1, el Kim-1 o el mitiquísimo Altair 8800 por ejemplo.

Recuperando temas que a veces no recordamos que vienen de muy lejos, los teclados:

Que el Keyport 717 tiene bien poco que envidiarle al más loco de los teclados actuales.

En la Kernel del mes nos encontramos con el lanzamiento de Excel en una conferencia conjunta de Microsoft y Apple porque, como igual no sabías, Excel era originalmente una aplicación para el Mac.

Kernel The ongoing construction work at Chaos Manor made it desirable for Jerry to escape yet again. He attended a joint press conference held by Microsoft and Apple in New York. The product introduced at the conference, Excel, is a spreadsheet for the Macintosh. Comments made at the press conference caused Jerry to put down some thoughts on software integration and whether or not we need it. He also looked at several new products, including a new version of BASIC from the inventors of the language. This being our anniversary issue, Dick Pountain brings us a condensed history of personal computing in Great Britain. He also introduces us to a rugged new lap-held portable, the Husky Hunter. From Japan, Bill Raike sends us an abbreviated history of that country's microcomputers and also discusses an innovative new product from Brother Industries— the SV-2000 Software Vending System. In this month's According to Webster, Bruce describes his experiences at the West Coast Computer Faire. He discovered that it isn't as much fun as it used to be, but he found some interesting products on display. He also discusses Apple's plans for the Macintosh, predicts success for the Amiga, and looks forward to testing a host of new products. Bob Kurosaka discusses the world of transcendental numbers in Mathematical Recreations. Some of them are familiar to us, such as e, the base of natural logarithms, and ir. He looks at some hiding places for these two numbers and some ways to approximate their values.

Y no podíamos saltarnos, claro está, sobre el textito que le dedica Pournelle al Amiga, por el que vota como sucesor del Apple II a finales de los ochenta. Ojalá, Jerry. Ojalá.

Amiga Among its other faults, Apple has been shamelessly neglecting the Apple II family, and specifically the Apple IIe. When the IIc came out a year ago, Apple cut the price of the IIe and slowed production, figuring the machine would die of its own accord. Instead, the sales jumped dramatically, easily outselling the IIe. People would see the IIc ads, come into the computer store, and walk out with a IIe. Why? Because the IIe had slots, while the IIc (like the Mac) was a closed machine. The IIe is a chameleon: With the right set of boards, you can make it look like and do just about anything. Case in point: The nicest development system I've ever used, including mainframes and minis, was an Apple IIe with 128K bytes of RAM, an AcceleratorIIe card (3.5-megahertz 65C02), and two Axlon 320K-byte RAM disks (configured as four 160K-byte floppy disks). Apple's response to the increased IIe sales was to cut back on production and raise its price (while discounting the IIc). Even so, it wasn't until late 1984 that the IIc finally started outselling the IIe. What does this have to do with the Amiga? Well, several machines are competing in the low-end market: the Atari 520ST the Apple IIe, the Mac (to a lesser extent), and the Amiga. Guess how many of these are easily expandable? Just one: the Amiga. Guess which machine will probably end up being the Apple II of the late eighties? I don't think the IIe will, nor the Mac, and the ST is a tightly closed, nonexpandable box. My vote is for the Amiga. From what I can see, the Amiga's graphics, sound, 68000 processor, memory map (allowing up to 8 megabytes of RAM), and expansion bus give it the potential of a long and successful life. There's always the chance that Apple will, indeed, come out with a souped-up Apple II next year, but even with the Western Design Center chips (65816. etc.) and the nifty 3 /2-inch Duodisk (1.6 megabytes of storage), it will probably be too little, too late.
(Dejo la imagen enlazada a la versión grande de la imagen, y no a la fuente en el Archive (aunque siempre tenéis la opción de leer el texto alternativo de la imagen).)

Y cierro con dos piezas más. La primera, lo normal en las revistas actuales (no): el típico artículo de dedicado a los números π y e…

pi, e, and All That Sneaking up on transcendental numbers by Robert T. Kurosaka God made integers, all else is the work of man. — Kronecker This famous quote of Leopold Kronecker serves as the starting point for this month's column. The integers (the whole numbers) can be used to construct other numbers. We can construct rational numbers by dividing one integer by another. When we do so, we get either a terminating decimal (1/4=0.25) or a nonterminating, repeating decimal (7/18 = 0.388888 ...). Repeating, or cyclic, decimals are a fascinating study I may explore in a future column. Irrational Numbers We can also construct numbers that are both nonterminating and nonrepeating. It is a rather amazing notion that a string of digits may go on forever without having to establish a pattern. It's such an odd notion that the ancient Greeks originally did not believe it possible— or even imaginable. When it was established that the square root of 2 was such a number, the Greeks called this kind of number irrational. The root meaning of irrational is "without ratio,'' or unable to be expressed as a fraction. The Greeks found such numbers irrational not only in the sense of "non-ratio-able" but also in the sense of "nonsensical." The differences between rational and irrational numbers are substantial. It can be shown that no more rational numbers exist than do whole numbers, but irrational numbers outnumber rational numbers. This fact, which is often presented as a paradox, is not especially surprising when you look at how we have constructed rational numbers. They are built up out of whole numbers and can be expressed as integer fractions. As I said above, irrational numbers cannot be so expressed. TWO TYPES There are two different kinds of irrational numbers. The first, like the square root of...

…y el segundo dedicado al Versabraille II, un ordenador diseñado para funcionar usando braille, porque la preocupación por la accesibilidad tampoco es nueva:

VersaBraille II Telesensory Systems has introduced the VersaBraille II system, a portable, disk-based electronic information processor for the blind. This braille computer lets you electronically store, process, and retrieve information. A special telephone modem can link VersaBraille II to other computers. VersaBraille II consists of a standard 3 '/2-inch microfloppy-disk system and a braille display that substitutes for a video monitor. Its memory holds up to 30.000 characters; disk support boosts the unit's capacity to 77,000 characters. This is adequate for many word-processing procedures, such as formatting, high-speed searching, and inserting, deleting, and relocating text. The system can simultaneously output braille and print information. VersaBraille II is fully programmable. Menus guide the user to each of the system's programs. The manufacturer provides special software that converts VersaBraille II into a four-function calculator with algebraic logic, floating decimal point, square root, and percent. Plans for other software packages include a 50,000word spelling checker, a two-way braille translator. and a language interpreter. The price of a VersaBraille II system is S6995 plus shipping and handling.

He encontrado poca información sobre el Versabraille II, pero si alguien quiere investigar sobre su antecesor, el Versabraille original, aquí un documento por el que comenzar.

Apa. Volvemos el mes que viene con el número de octubre. Por cierto, que si alguien quiere hacer los deberes por su cuenta, además del archivo de la revista en el Archive, también tenéis esta chulada de navegador que me pasó hermanito hace unas semanas.

¡Hasta la próxima!

Auriculares para dormir, segundo intento: Soundcore Sleep A30

— A ver… si no has hablado nunca del primer intento.
— Porque fue fallido. Hace un tiempo me apunté al Indiegogo de los Ozlo Sleepbuds, pero no me acabaron de convencer…
— [Googlea.] ¿Más de doscientos euros?
— 😤
— ¿Y estos algo mejor?

Foto de la caja del producto, y de la caja que carga los auriculares, con los auriculares dentro. Tanto la caja de carga como los auriculares son muy similares a los de cualquier otros auriculares 'true wireless'

Sí, estos Sleep A30 me están convenciendo bastante más, aunque no están completamente libres de problemas. Si queréis investigar un poco por vuestra cuenta, aquí el Kickstarter (los 160 euros de la campaña, comparando, fueron muy poco dolorosos), y en Amazon ahora mismo están a 250, y una review en Mashable.

El objetivo

Uno se acostumbró, hace muchos años, a dormirse escuchando la radio. Y a veces no quieres hacer ruido. En otras ocasiones, lo que no quieres es que te afecten los ruidos que tienes a tu alrededor. Los auriculares son la opción obvia en ambos casos, pero para los que dormimos de lado o boca abajo, son cualquier cosa menos cómodos. Unos ingenieros de Bose decidieron hace unos años que unos auriculares «true wireless» lo suficientemente pequeños como para no sobresalir de la oreja (y por lo tanto, no clavársete en ella) serían la solución. De ahí nacieron los Bose Sleepbuds. Al cabo de un tiempo, Bose decidió cancelar el producto porque la cosa no tenía el recorrido económico que exigen a sus productos… y una parte del equipo decidió comprar las patentes y seguir adelante con Ozlo. En paralelo, Soundcore, la marca de auriculares y altavoces Bluetooth de Anker, se animó a sacar su alternativa, en la forma de los Sleep A10, a los que siguieron los A20 y, ahora, estos A30.

No sé con las primeras versiones, pero con las actuales, la idea es que los auriculares pueden usarse conectados al móvil reproduciendo el audio que se quiera, pero que también tienen algo de espacio para almacenar algún archivo de sonido que los auriculares pueden reproducir sin tirar de bluetooth y, por lo tanto, con menor consumo energético. En general, se trata de bucles de sonido ambiente como los que podéis encontrar en multitud de webs (aquí, un ejemplo).

Lo bueno

Si el precio no os marea, la verdad es que, en mi experiencia, casi todo bien, y más aún si los comparamos con los Sleepbuds..

Las cajas de los Sleep A30 y los Sleepbuds. La caja de los Sleepbuds

El primer punto positivo es que los A30 (como sus antecesores A10 y A20) son algo más pequeños que las diferentes generaciones de los sleepbuds, cosa que los hace bastante más cómodos, al menos para las orejas del que suscribe, que nunca se acabó de acostumbrar a los auriculares de Ozlo.

El segundo punto es la cancelación activa de ruido, presente en los A30 (no en los A10 ni en los A20), y que eché mucho en falta en los sleepbuds. No se puede esperar que la cancelación de unos auriculares de botón sea fantástica, y menos aún en estos minúsculos A30. Y no lo es, pero algo ayuda, y se agradece bastante que esté ahí.

Y el tercer punto a destacar es el del software. Para comenzar, en ningún momento me han dado ningún problema para conectarse con mi móvil por Bluetooth, cosa que no puedo decir de los sleepbuds (espero que hayan solucionado el problema desde entonces). Además, en mi experiencia, los auriculares son capaces de detectar en qué momento te quedas dormido para, en ese momento, pasar del audio del teléfono al sonido ambiente que le hayas programado o al silencio, con la ayuda de la cancelación activa de ruido si se desea. Como decíamos antes, esto tiene el efecto, además, de ahorrar bastante batería.

Y, por si fuera poco, con la ayuda de algunos sensores, los auriculares se apuntan a la moda de los wearables capaces de monitorizar tu sueño:

Captura de pantalla de la aplicación. Indica 6 horas 48 de sueño, 7 horas 2 de tiempo en la cama, que me he despertado una vez y una eficiencia del 97 por ciento. También muestra las fases del sueño. Y se ve que hay dos pestañas más, sobre ronquidos y movimiento durante el sueño.
Para mi sorpresa, la app dice que no he roncado esta noche. En cuanto a movimiento durante el sueño… creo que tengo vocación de pollo al ast 😶.

No puedo asegurar la precisión de los datos, pero verosímiles lo son… Y la aplicación también monitoriza el ruido a tu alrededor (ronquidos ajenos incluidos) y sugiere sonidos de su catálogo especialmente adecuados para enmascararlo.

PS 20250904 Comenta David aquí abajo, y tiene toda la razon, que (i) los Sleepbuds son bastante optimistas interpretando los datos de sueño y (ii) que no registran la fase REM. Ambos aspectos son importantes, si te importa la funcionalidad de monitorizado.

¿Y el problema?

El problema, me temo, es inherente a unos auriculares «true wireless» especialmente pequeños y que usas en tiradas de seis horas o más, con lo que cada noche que los uses los vas a dejar prácticamente «sin pilas». Y, así, al ritmo de un uso un ciclo de carga de las baterías… la vida de esas baterías, inevitablemente, va a ser más corta de lo que uno querría. Espero que Anker se haya preocupado de que la caja, que es la responsable de cargar los auriculares (tiene batería para cargar los auriculares para tres noches), lo haga con mimo (confío en ello, de hecho). Y no es que el problema vaya a ser peor que con cualesquiera otros auriculares de este tipo. Pero con estas cosas no hay milagros. (A veces pienso que estaría bien que estas empresas sacaran diademas, que serán mucho más cutres, pero que necesitan una radio, y no dos, y en las que cabe una batería más grande y que necesite menos ciclos de carga….)

El veredicto

Los A30 son un juguete caro (digo yo que dentro de unos meses comenzarán a bajar de precio), pero hacen lo que dicen hacer con bastante efectividad, y la limitación que les encuentro, insisto, es inherente a su categoría de producto. Personalmente, opino que son muy recomendables. Si os apetece comprar en Amazon, aquí un enlace de afiliado.

PS 20250922 Actualizo con enlace a la review de The Verge, que coincide con David en afirmar que las estadísticas de sueño son muy optimistas, pero además incluye pruebas prácticas del enmascaramiento de ronquidos con resultados bastante positivos, entre otras cosas.

Byte, agosto del 85 (y el lanzamiento del Amiga)

Decíamos «ayer» que el número de agosto de la revista Byte (de 1985, porque en esta casa siempre hemos ido con un cierto retraso 😬, especialmente en este miniproyecto nuestro de repasar la «actualidad» de la informática a través de la revista) venía interesante. Y no mentíamos:

Portada de la revista Byte de agosto de 1985. Se ve el cuadro Jeune fille dessinant dans un interieur, de Picasso, y una reproducción del mismo en la pantalla de un ordenador Amiga 1000. El otro tema de portada son los lenguajes declarativos, de entre los que se destacan Prolog, Hope y FP
Sí, es un Picasso. De la colección del MoMA. Si queréis el título, siempre podéis hacer una búsqueda de imágenes… o acceder al texto alternativo de esta captura.

El Amiga 1000. Probablemente, mi ordenador favorito. En la portada de la revista Byte.

Debe decirse, primero, que en aquella época no era exactamente habitual tener un ordenador en la portada. Antes del Amiga, el PC de IBM en el número de enero del 82 y el Lisa (acompañado del Apple IIe) en el de febrero del 83, y muy, muy pocos otros: un par de Compaqs justo antes del Lisa, en enero del 83, el HP-150, un fallido intento de ordenador personal MS-DOS de Hewlett Packard (¡con pantalla táctil!), en octubre del 83, el Mac en febrero del 84, y el Data General/One en noviembre del 84. Y después del Amiga, llegarían el PC UNIX de AT&T en mayo del 85, el Atari ST en marzo del 86, el Macintosh II en abril del 87 y el Personal System/2 de IBM en junio del mismo 87. Vamos, que tres al año como mucho.

(También podríamos destacar la puntería de la revista en seleccionar ordenadores de poco recorrido comercial, pero no vamos a hacernos daño…)

The AMIGA Personal Compuer Its speed and colorful graphics come from a 68000 and sophisticated custom chips There are two ways to get works done inside a computer: do it in software or do it in hardware. The first way gives you unlimited flexibility; the other, speed. The Apple Macintosh does almost everything in sofware—and...

Si seguimos leyendo, nos encontramos con cosas como

Por 1295 dólares, el Amiga promete gráficos de metáfora de escritorio a color y rápidos como un relámpago, con el doble de memoria y disco que el Macintosh por cientos de dólares menos.

También destaca el artículo la arquitectura del Amiga, con sus tres chips especializados (Paula, Denise y Agnes, diseñados por el legendario Jay Miner), conectados por buses de una velocidad inaudita en la época, el copper y el blitter de Agnes y sus capacidades gráficas (que alguien se haya tomado la molestia de replicar la documentación del sistema operativo en su versión de 1993 es un indicativo más del amor que despertaba y sigue despertando el Amiga), hasta 4096 colores en pantalla de una paleta de 24 bits (el primer Mac en color, el Mac II, salió en el 87, por algo más de 3700 dólares), y el multiproceso real con el que el resto de ordenadores personales de la época no podían ni soñar en 1985 (tanto es así, que el artículo dedica algún párrafo a explicar qué es la multitarea). Y también se fijan, claro, en que el sistema operativo ofrecía a las aplicaciones el uso de bibliotecas de funciones, otro aspecto tremendamente innovador por aquel entonces. Un sistema operativo elegante para un hardware igualmente distinguido.

(Merece también especial mención el nivel de detalle técnico al que entraban las revistas de la época, como ya hemos comentado alguna vez por aquí. En serio, haced clic en la captura del artículo para acceder a la revista y echadle una ojeada.)

Como es el Amiga, no puedo irme sin dejar un par de vídeos de «contenido complementario». Por un lado, este repaso a la máquina…

Y por esto, aprovechando que, obviamente, el Amiga acaba de cumplir cuarenta años, este vídeo de la celebración del cumpleaños.

En el vídeo encontraréis todo tipo de historias y batallitas del desarrollo, incluyendo el primer anuncio en el CES de enero del 84 (hay un universo paralelo en que la escena del CES de Halt and Catch Fire está protagonizada por esta gente… y seguramente el mundo de la tecnología es un poco menos tóxico que en nuestro universo).

El segundo vídeo, por cierto, sale de una noticia en Tom’s Hardware sobre el tema y el avistamiento del prototipo que se mostró en el CES (quién fuese rico para ofrecer una pasta por él).

Volviendo a la revista, unas páginas más adelante nos encontramos con un anuncio del otro ordenador nuevo de Commodore, el 128:

Anuncio del Commodore 128. Vemos una foto del Commodore 128, con un monitor, una disquetera de 5¼ y un teléfono. El texto habla de la capacidad del 128 de ejecutar software del Commodore 64 y CP/M

El 128 había sido anunciado en el número de febrero, y uno diría que la duplicidad 128 / Amiga era señal de la mala gestión de la cartera de productos de Commodore… pero Apple hacía lo mismo con el Apple II y el Mac.

Un poco más adelante nos encontramos con lo que eran los PCs de la época. Las comparaciones, efectivamente, son odiosas…. pero seguimos en un mundo Wintel (y cada vez más Mac, ciertamente). Mil dólares por el ordenador con 128 kBs de RAM y una disquetera (de discos de 360 kBs)…

System Review The Tandy 1000 When I first heard about the Tandy 1000, I was quite impressed. It seemed to have almost everything I would want in an IBM Personal Computer clone. Plus, it had some of the better features of the PCjr. For those who haven't seen this machine yet, the Tandy 1000's features include one 360K-byte disk drive (expandable to two, plus one 15-megabyte hard-disk drive), 128K bytes of memory (expandable to 640K bytes), a parallel printer port, interfaces for composite monochrome and RGB (red-green-blue) monitors and a light pen, graphics and sound similar to those of the PCjr, joystick ports, three IBM-compatible expansion slots, a general-purpose collection of software (DeskMate), and a fairly good price ($999). Even a full BYTE configuration (two floppy drives, 256K bytes of memory, monochrome monitor, and serial port) has a reasonable cost ($1746), considering that you get some free software bundled with it. Description Since BYTE has published a product description of the Tandy 1000 (see "The Tandy 1000" by G. Michael Vose, December 1984, page 98), I will skip most of the details. Suffice it to say that the system Tandy sent me (two drives, 256K bytes of memory. RGB monitor) fits nicely on my desk and has attracted quite a bit of attention (see photo 1). The system's fan is quieter than that in my IBM PC. and I doubt it will be a disturbance in the office or the home. I have left it on for long periods without noticing it. The disk drives follow the Tandy tradition of putting the primary A drive below the optional B drive. And while the disk drive latches do not have that feel of quality I have noticed on other machines, the disk drives themselves are fairly quiet and seem to work well. The machine's general design is logical. The on/off switch is on the far end of the right side of the machine (just like IBM), but many other items are on the front where they are accessible. These include the keyboard and joystick connectors and a red reset button. You access the expansion-board slots through the front as well. Keyboard Tandy seems to know how to design keyboards. Apparently recognizing a good thing when they see it, Tandy's designers reissued the Tandy 2000 keyboard with hardly a key label changed. The Tandy 1000 keyboard (see photo 2) has the same layout, the same superior feel, and the same welcome relief from the standard clone keyboards that keep appearing on the market. Some of its better features are a separate inverted-T cursor-key layout, a left Shift key and carriage return in the places where you would expect them, indicator lights for the Caps and Num Lock keys, 12 function keys arranged horizontally, and a Hold key. In short, it is one of the better keyboards on the market. The only aspect of it I don't like is that the function keys are too close to the numeric keys. For example, I sometimes hit the 5 key when I mean to hit F5. Also, if you are accustomed to IBM's vertical function keys, the horizontal arrangement can be confusing. And since some of the keys have different key codes than those on the IBM PC. you might find that in a small number of programs these keys do not work as they should. For example, the XyWrite II Plus word processor does not recognize the Tandy's cursor keys. It looks to the numeric keypad, as on the IBM PC. Fortunately, XyWrite II Plus lets you reconfigure the keyboard as you wish.

Y nos vamos con tres breves. Primero… no, lo de volvernos locos por los editores de texto, tampoco es nuevo. Dentro de la sección Kernel de Jerry Pournelle nos encontramos con EMACS (y Richard Stallman):

Yet Another EMACS Another minibooth featured EM-it, an EMACS imitator. EMACS is the macro editor written at MIT by Richard M. Stallman (otherwise known as RMS). EMACS was one of the very first full-screen editors in existence. I recall several long-distance debates (I have an account on one of MIT's large computers) with RMS over the virtues of EMACS versus Electric Pencil, which was the editor I was using at the time. The debates were futile, of course: Pencil and WRITE (derived from Pencil) were much better editors for creative writing, but EMACS was far and away better for programming, and indeed it became a bit of a legend among hackers. Stallman, who believes software ought to be available to everyone, put EMACS in the public domain instead of getting rich from it. The chaps at Sayansi have implemented it for PCompatibles and sell their version for $49.95, a reasonable price. Needless to say, it's not copy-protected. It's also not full EMACS. One of the main features of EMACS is its extensibility: you can add nearly any feature you might want from right inside the editor. EM-it can't do that, but it does...

Si seguimos avanzando, nos encontramos con el mítico Amstrad CPC6128 y sus discos (que ya no recordaba yo)… ¡de 3 pulgadas! Otra colección de máquinas, la de Amstrad, que merecía mucho más éxito comercial del que tuvo.

The Amstrad CPC6128 PC Amstrad's CPC6128 is a 128K-byte microcomputer based on Zilog's 4-MHz Z80A microprocessor. It has 48K bytes of read-only memory for BASIC and the operating system. An AY-3-8912 sound-generator chip provides three-voice, eight-octave capability. The system's standard equipment includes the CP/M and AMSDOS operating systems, the BASIC and Logo languages, a built-in 3-inch disk drive, a color or monochrome monitor, and software. Its 76-key QWERTY-style keyboard has a separate numeric keypad and enlarged enter, shift, caps lock, tab, delete, clear, control, and escape keys. Built-in ports let you add peripherals such as a printer, speech synthesizer, modem, second disk drive, stereo amplifier, joystick, and tape saver. The system comes with three blank 3-inch floppy disks. The CPC6128 comes in two configurations. The first has a 640- by 200-pixel RGB monitor, one 3-inch floppy disk drive, and a word processor; it has a suggested retail price of $799. The other model has the same single disk drive, a green monochrome monitor, and WordStar: it costs $699. The manufacturer offers more than 100 applications packages available in the 3-inchdisk format.

Y más adelante aún, como es natural, este paquete de IA y Forth… ¡para el Commodore 64!

Programming Environment with AI Module Superforth 64 + AI, an integrated package for the Commodore 64, is a programming environment that includes an artificial intelligence module and advanced math capabilities. The package is designed to help you develop expert systems. At Superforth's core is a programming language that lets you define your own English-like "word" functions. These words are stacked to create rules; an interpreter then applies the rules to make decisions. Antecedent and consequent reasoning are possible. The program incorporates the utilities needed to write applications, including full control of color graphics; sound, music, and sprite editors; trace and decompiler facilities; and virtual memory. Superforth 64 + AI sells for $99.

Y el último, considerad que este anuncio de la propia revista pretendía dar una imagen atractiva y moderna del informático de la época:

En el anuncio de Byte, el informático es un señor de americana y corbata con una prominentísima calva.

En fin. Lo dejamos aquí. En otra ocasión le habría dedicado un tiempo a los artículos sobre Prolog, la programación lógica (firmado por Robert Kowalski), o los lenguajes declarativos (cofirmado por Susan Eisenbach, manía tienen los autores de Byte de la época de acabar en la Wikipedia), entre otros, que componían el otro tema de portada de la revista, pero me temo que este mes gana el Amiga…

Si no pasa nada, volvemos el mes que viene. Si tenéis curiosidad por seguir leyendo, aquí tenéis el número de agosto del 85, y también el archivo completo de la revista en Archive, por si queréis avanzar tarea. ¡Hasta la próxima!

Byte, julio del 85

Seguimos con nuestro proyecto de hojear, con un delay de cuarenta años, la revista Byte. Este mes el tema de portada es el espacio y la informática y no vamos a encontrar joyas especialmente interesantes… (El número de agosto será mucho más interesante, puedo prometerlo.)

La portada de la revista Byte de julio de 1985. La imagen de portada en un enorme disquete de cinco pulgada y cuarto. El tema de la revista es Ordenadores y espacio

En las noticias tenemos que comienzan a llegar los sistemas con procesadores 286 (en el número de mayo habían comentado la llegada del IBM PC AT):

New 80286 Systems Flood COMDEX Late spring saw the introduction of many new IBM PC AT-compatible computers. By mid-May, new 80286-based systems had been announced by Kaypro, ITT, Compaq, TeleVideo, Corona, Texas Instruments, Zenith, NCR, Tomcat, and Basic Time. Another multiuser AT compatible computer, available from MAD Computer in both floor and desktop models, will be sold only to other manufacturers. Wang also disclosed that it is developing an AT-compatible system. Intertec, West Columbia, SC, has redesigned its HeadStart computer, replacing its 8086 processor with an 80286 and eliminating its 3½ inch disk drive. The HeadStart ATS's standard 256K bytes of RAM can be expanded to 3 megabytes; the computer also includes serial, parallel, and network interfaces. The basic HeadStart ATS is priced at $1895 without disk drives. A dual 5 '/4-inch disk-drive add-on unit is $495 extra. Intertec also announced several 80186-based file servers for its MultiLAN proprietary polling network; a $695 interface card also allows IBM PCs to be attached to the network.

Mientras quede «contenido Commodore», lo seguiremos recogiendo por aquí, esto es un hecho:

Anuncio a doble página del Commodore 128 en el que explica todas las cosas que habría que añdir a un Apple IIc para conseguir la potencia de un Commodore 128, como las capacidades de sonido.

¿No os recuerda un poco al dichoso anuncio de hace unos meses de Apple en que aplastaban todo tipo de herramientas creativas? Igual es que Apple estaba recuperando el trauma de este anuncio anti-Apple de hace apenas cuatro décadas…

En la sección de libros nos encontramos otro tema recurrente: la accesibilidad.

PERSONAL COMPUTERS AND SPECIAL NEEDS Reviewed by John Wilke In 1977, a group of activists with a variety of disabilities staged a symbolic sit-in at the Department of Health, Education, and Welfare to demonstrate support for a bill frequently called "the civil rights act for the disabled." Since that legislation became law, engineers and city planners must design public buildings that are accessible to all people. The young man who led the HEW demonstration and lobbied successfully for the new law has turned his attention to overcoming another set of barriers: software, computers, and communications equipment that, by design, shut out the disabled. Frank G. Bowe is quick to point out in Personal Computers and Special Needs that just as new technology is beginning to make it possible for disabled individuals to not only communicate more effectively but also pursue meaningful employment in the information industry, there is a lack of physically compatible and affordable computer interfaces. This paradox is an underlying theme in Bowe's book, a survey of personal computer peripherals and communications prostheses available to people whose hearing or vision is impaired or who are unable to manage normal movement. Bowe takes what might have been little more than a listing of the latest in speech synthesizers and keyboard emulators and peoples it with firsthand accounts of how the devices are making life more productive for disabled people. Unifying this effort is his concern that with the transition to an increasingly information-based economy— with its obvious promise of fuller participation for the disabled—the danger remains that a new set of barriers will prevent them from participating. The book, then, addresses both how-to and why. It was written first for the nearly 30 million Americans who might...

El comentario de siempre: hace más de cuarenta años que unos cuantos se interesan por el potencial de las tecnologías digitales para ponerlo todo al alcance de las personas con discapacidad… y el resto que no le presta ni la más mínima atención al tema. El libro, (Personal Computers and Special Needs) por cierto, está disponible en archive.org.

En el número de marzo habíamos hablado de pantallas planas que usaban paneles de plasma y pantallas electroluminiscentes, las tecnologías que hoy sabemos que no iban a tener éxito. Ahora llegamos a los LCDs:

Liquid-Crystal Displays for Portables Inside the display technology that has made portable computers portable Several months ago I got into a discussion with a computer enthusiast about which portable computer to buy. I quickly whipped out my portable and began preaching its merits and demonstrating how powerful it is. I could see the display perfectly, but the fellow standing next to me was having difficulty reading what I had typed. Poor display quality is a common limitation in portable computers. Most portables (not to be confused with transportables) have twisted-nematic liquid-crystal displays (TNLCDs), with restricted viewing angles and limited contrast. They must be operated under proper ambient lighting conditions. In mid-1982, there were only a few low-profile displays on the market. Of the available technologies, TN-LCD was the only one that had acceptable power requirements for battery operation. A typical 16-line LCD module dissipates approximately % watt (W). Other available flat-panel technologies...

(Por cierto, si os atrevéis a seguir el enlace (cada escaneado está enlazado a la página correspondiente de la revista en Archive), sabed que os vais a encontrar una discusión bastante técnica de la tecnología LCD.)

Y llegamos al tema de portada:

COMET LINES IN FORTRAN by David S. Dixon The program described calculates the positions of asteroids and comets THE PROGRAM DISCUSSED in this article is intended to allow amateur astronomers to calculate the positions of asteroids or comets with greater accuracy than the programs previously published in general literature. Written in FORTRAN IV, the program should be translatable to any BASIC that supports double-precision calculation. But be advised that this is a number-crunching program: it may run for hours if rewritten in interpreted BASIC Asteroids are a very challenging target for the observer: they appear as points of light just like the stars. Depending on the asteroid's position relative to earth, it may or may not demonstrate detectable motion against the background stars. Frequently, several nights of observation are required to see displacement and identify the asteroid. Successfully hunting a particular asteroid usually means having a good idea of the asteroid's position at the intended time of observation and having a good set of star charts. The problem is that accurate tables of locations for asteroids, known as ephemerides, are not easy to come by. The United States Naval Obser- vatory publishes ephemerides for the four major asteroids in The Astronomical Almanac each year, but there are thousands of named asteroids. (For a list of books and periodicals mentioned in this and other articles, see the 'Astronomy Sources" text box on page 244.) The Soviet Union's Institute of Theoretical Astronomy publishes the Ephemerides of Minor Planets, which gives ephemerides for thousands of asteroids, but only for a few weeks at opposition, and it is a difficult publication to obtain. Both the Russian and the Naval Observatory publications, however, also give the orbital elements for a large number of asteroids, and with the elements it is possible to calculate the ephemerides of an asteroid yourself. Many of the books and magazine articles that address calculating the position of a planet solve the problem by the model devised by Johannes Kepler in 1609. The method models the motion of a body in the solar system as involving only the sun and the body in question. This means that to find the relative positions of Earth and Mars in a common coordinate system you solve the two-body sun-Mars problem, solve the two-body sun- Earth problem, and, using spherical trigonometry, combine the two results to solve the Earth-Mars problem. The method can produce results satisfactory for use in finding planets, but the accuracy for use on asteroids is frequently inadequate. Kepler's model is a remarkable achievement since he derived it by geometry as an empirical solution based on position measurements made by lycho Brahe. Kepler's model is summarized in his first two laws: First law: The orbit of each planet is an ellipse, with the sun at one of the two foci. Second haw: The line joining the planet to the sun sweeps over equal areas of the ellipse in equal intervals of time. It was not until more than 50 years after Kepler's work was published that the work of Sir Isaac Newton explained the process that Kepler's model described and how the model was incomplete. Newton's law of gravi

Imagino que no sorprenderá a ningún lector habitual de obm encontrarse a un ingeniero de la NASA describiendo un programa en FORTRAN IV (yo hice mis pinitos con FORTRAN 77 unos pocos años más tarde) para trazar órbitas de asteroides y cometas. Lo mismito que ahora.

FORTRAN 77, por cierto, se lanzó en 1978, el IV es de 1961, y no me tiréis de la lengua con lo de la evolución del software y el uso de un lenguaje de más de veinte años de edad en el artículo. (Rascando un poco por la Wikipedia, compruebo que Fortran (perdió las mayúsculas en la versión 90 que, como adivinaréis, es de 1991) está ahora mismo el 12 en el TIOBE, un ranquin de uso de lenguajes de programación.)

Unas páginas más allá encontraréis un programa de seguimiento de satélites, y a continuación otro artículo sobre el control de telescopios. Y en la página 265, la crítica de una aplicación para seguir el cometa Halley, que pasaría por el sistema solar en 1986 (se le espera de nuevo a principios de 2061).

Y aprovecho que el número tenía poca «chicha» para detenerme en una de las columnas más míticas del periodismo sobre informática, el Computing at Chaos Manor de Jerry Pournelle.

Pournelle, fallecido en 2017, se dedicaba a la investigación operativa (con finalidades militares, parece ser), a escribir ciencia ficción (con un par de best sellers escritos a cuatro manos con Larry Niven), y a ser el power user de los power users con su columna, que apareció en la revista desde 1980 hasta 2006. Y en la columna narraba sus aventuras y desventuras con su extensa colección doméstica de ordenadores, que yo me leía (debía entender la cuarta parte, con suerte) con fascinación.

Quien dice «columna» dice «minirevista»: la de este número arrancaba en la página 309 y se iba hasta la 338 (con mucha publicidad de por medio, sí, pero vaya, que es un atracón), seguida de una página de correo de los lectores específica de la sección.

¿El contenido? Comenzamos con una visita a una feria informática que incluyó comer con Niklaus Wirth (ojo a la broma que se le atribuye sobre la pronunciación de su nombre que incluye la pieza). Seguimos con una discusión sobre si el futuro era de Intel y sus 286 y familia o de Motorola y sus 680×0, que se enlaza con una batallita sobre compiladores de Modula-2 (lenguaje creado por… Niklaus Wirth). Y si Wirth no fuese suficiente, luego tenemos una feria sobre el Mac en la que cenó con Frank Herbert. Sí. Ese Frank Herbert (que fallecería en 1986, por cierto). Pournelle iba a comprar un segundo Mac con la intención de ampliarlo a un mega de RAM (la mitad de la cual, dedicada a disco en memoria, que el Mac no podía direccionar más de 512 KBs), por apenas 1500 dólares.No descartamos que en el futuro se cuele alguna batallita «Chaos Manor» más.

En fin. Lo dejamos aquí (ya decía que no fue un número especialmente interesante, el de julio del 85) y recuperamos el mes que viene, mucho más interesante, al menos para mí.

Si alguien quiere entrar más a fondo, aquí está el número de julio entero, y aquí el archivo completo de la revista en Archive.