Byte, diciembre del 85

Toca cerrar el año con nuestra relectura habitual de la revista Byte… de hace cuarenta años. Esta vez, temas de moda… de 2020.

Portada de la revista Byte de diciembre de 1985. El tema es "computer confeerencing", con una ilustración de un conector tipo D con un cable plano... pero en el que los pines del conector son personas sentadas a una mesa.

(Me vais a reconocer que aprovechar un conector tipo D así es, cuando menos, creativo :-).)

Y comenzamos con publicidad, más que por el producto… porque en 1985 ya hacía unos años (pocos, eso sí) que Bill Gates había dicho (o no) que 640 Ks deberían ser suficiente… y ya sabíamos que no.

Anuncio de una ampliación de memoria de dos megabytes, con el eslogan "para aquellas ocasiones en que 640 ks no parecen ser suficientes"

Por cierto. Cuarenta años más tarde, tu ordenador tiene… ¿cuatro mil veces más memoria? ¿Ocho mil?

En la sección «cosas que no son nuevas»…

And Now, Adware

In response to the letter by Mr. Tate ("Don't Sell Software. Sell Ad Space," August, page 26) regarding the selling of advertising space in entertainment software: Wow! What a great idea. Adware (that's my term for it) could resurrect the failing home computer industry

Let's face it, most home computers are used for entertainment; however, the general public is not usually willing to spend S30 to SI 00 for a game. In general I feel that this attitude applies to all types of home entertainment. Look at how successful television has become simply because you don't have to pay for it to enjoy it (unless you want cable or pay TV, but even that is relatively inexpensive). With Adware you would still have to incur the cost of downloading from the telephone. This same reason also accounts for the to-date unsuccessful home videotex systems.

Mr. Tate mentions the advantages of Adware but fails to mention the virtues of the Freeware concept and what Adware could bring to it. I personally do not agree with the idea of selling copy-protected entertainment software commercially. Computers are very good at copying software, and so this fact should be put to good use. Freeware (the free distribution of software by encouraging copying) offers the users a better and more dynamic product. For example. I have a Freeware product that I continue to update as improvements and additions are implemented. When a new release is ready I simply make it available on the Freeware market. You cannot do this economically with a similar commercial product without covering your expenses by raising the retail price. With Adware you could make it a policy to release a new version every few months to insure a dynamic advertising medium.

At present the Freeware distribution network is not firmly established, but if the amount of Freeware and the demand for it grew large enough I am sure that regular channels would establish themselves quickly so that everyone could have almost immediate access to the updates. Another benefit of this concept would be...

…y es que el debate sobre los modelos de financiación del software vendría a ser tan viejo como el propio software.

No nos vamos a saltar nunca las tecnologías para mejorar la accesibilidad de los ordenadores:

The Audiodata/IBM PC Keyboard from Frank Audiodata GmbH of West Germany uses tone and speech capabilities to make the IBM PC accessible to blind and visually impaired users. The system generates different tones depending on the type of data at the cursor's screen location. To position the cursor, you use sliding switches that correspond to the horizontal and vertical axes.

The vertical switch is on the left-hand side of the Audiodata keyboard, next to the function keys. Moving it from top to bottom yields a series of tones that tells you whether lines are blank or full of text. The horizontal switch is below the space bar. Moving it left and right yields tones that indicate letters, spaces, numbers, and punctuation marks in a line. By moving the switches and listening to the resulting tones, you can tell how many characters of what type are at what position on the screen.

The keyboard contains a Votrax SC-01 speech processor, so you can literally have the system read a portion of text out loud. Pressing a button on the vertical switch tells the system to read the line of text that corresponds to its position. Using the vertical and the horizontal switches together, you can have the system read or spell particular words.

The Audiodata keyboard works with standard or large-print monitors or with no monitor at all. It comes with a 6-inch add-in card and the system software for S3450.

Vamos a escandalizarnos, eso sí, de los 3450 dólares de la época que costaba el cacharro. Mucho más barato era este prototouchpad (que más que touchpad era un teclado para macros):

Touchpad Accessory for the IBM PC

Polytel Computer Products has introduced the Keyport 60. a small rectangular touchpad that fits along the top of the IBM PC keyboard. It has 60 touchsensitive regions that can be programmed as function keys and defined in regular and shift modes, so the Keyport 60 will accommodate a maximum of 120 macro commands.

To record a macro, you press the Alt key on your regular keyboard and a touchpad key simultaneously. Any keystrokes that follow are recorded until you press the Alt and touchpad keys a second time.

The touchpad package comes with KPEDIT. a fullscreen editor that allows you to edit key definitions.

Keyport 60 works with the IBM PC, XT, AT, and compatible personal computers, using the joystick adapter to allow concurrent operation with your regular keyboard It costs 399.

Aquí una cosa que no deja de sorprenderme que no hubiesen añadido antes en la revista. Uno se pasó una parte no negligible de los ochenta tecleando código que venía en diferentes revistas. Con mis nulos ingresos en la época, tiempo bien empleado. Pero el comprador de una revista como Byte muy probablemente tenía recursos económicos como para no verlo así:

Página anunciando un nuevo servicio de la revista: la venta de disquetes con el código incluido en la revista. Puedes optar entre disquetes de cinco y cuatro para IBM PC, Apple II en dos tipos de formato, Commodore 64, Hewlett Packard 125, Kaypro 2 CP/M. dps modelos de TRS-80, Texas Instruments Professional, Zaith Z-100 y Atari. En tres pulgadas y media, los formatos son Apple Macintosh, Atari ST, Commodore Amiga, Hewlett Packard 150 y Data General/One.

Los precios van de los cinco dólares de un disco de cinco y cuarto en Estados Unidos a los 8 para discos de tres y medio u ocho pulgadas enviados a Asia, África y Australia.

También se anuncia Bytecom, "conferencias informáticas entre los lectores de Byte en Europa, unas cuantas BBS fuera de los Estados Unidos.

Y, de regalo, nos dan el ránquin de los ordenadores más populares entre los lectores de la revista en la época. Nótese también, primero, que ahí están los discos de 8″ en formato estándar CP/M, y que los precios, teniendo en cuenta que la operación tenía que ser bastante manual, me parecen bastante razonables.

No pongo captura porque el escaneado de las páginas correspondientes en el Archive no está bien (podéis navegar a la página correspondiente de Byte – a visual archive), pero está bien la sección de libros del número. Comienza con la crítica de Back to BASIC: The History, Corruption, and Future of the Language (se puede conseguir en Amazon, curiosamente), en que los diseñadores de BASIC, al parecer, se quejan amargamente de la cosa en que se ha convertido su lenguaje, veinte años después de su creación, y explican por qué lanzaban en 1985 True BASIC (que exista el dominio y se puedan comprar en él versiones del lenguaje actuales y vintage, y manuales, me ha reventado la cabeza). Explican los autores que BASIC no fue diseñado para ser un lenguaje interpretado, sino compilado, y que esto, sumado a las estrecheces de la RAM de los ordenadores en que se estaba usando en los 80, se habían cargado su diseño. Qué cosas.

Más adelante se critica Ethical Issues in the Use of Computers. De nuevo, la digitalización del Archive está mal, pero se puede acceder al visual archive, para recordarnos que este no es un tema de nuestro siglo XXI, precisamente, y que hace cuarenta años ya nos preocupaban los riesgos de las grandes bases de datos para nuestra privacidad, la brecha digital o la toma de decisiones algorítmicas sobre nuestra salud.

Volviendo al servicio de venta de disquetes con el código de la revista, y en nuestra habitual sección «cosas que no se incluirían hoy en una revista ni por casualidad»…

A SIMPL COMPILER PART 1 : THE BASICS

by Jonathan Amsterdam

An implementation of a compiler for a simple structured language

In this article— the first of a three-part series on the construction of a compiler for a high-level language— 1 will discuss the basics of the compiler. Next month 1 will talk about procedures and functions, and in the third part of the series 1 will describe some of the compiler's extensions.

Three of my earlier Programming Projects are prerequisites for this one. "Context-Free Parsing of Arithmetic Expressions" (August, page 138) explains the parsing technique I will be using. "Building a Computer in Software" (October, page 112) describes VM2. the virtual machine for which my compiler is targeted. And "A VM2 Assembler" (November, page 112) details the assembly-language code that the compiler will generate.

The SIMPL Programming Language

I will be describing a compiler for a language of my own design, called SIMPL. SIMPL, which stands for "SIMPL Isn't Much of a Programming Language," isn't much of a programming language. SIMPLs grammar is given in figure 1. There are a few points that are not described by the grammar. An identifier is any string of letters and numbers beginning with a letter. Unlike most implementations of Pascal, SIMPL is case-sensitive, so the identifiers READ and Read mean different things. SIMPL keywords, like PROGRAM and BEGIN, are capitalized. Comments in SIMPL are delimited by braces ({ }). As in Pascal, character constants are delimited by single quotes, but SIMPL also allows the backslash character ( \ ) to act as an escape. When followed by an n or a t, the backslash denotes a new line (carriage return) or tab; when followed by any other character, it denotes that character. For example, the character constant for the single quote looks like ' \ '.

SIMPLs WHILE and IF statements, like those of Modula-2, are explicitly terminated by an END. The AND operator has the same precedence as OR, and both have weaker precedences than those of all other operators, so it is unnecessary to put parentheses around expressions connected by AND and OR. Furthermore, expressions surrounding an AND or OR will be evaluated from left to right, and no more than necessary will be evaluated. For example, in the expression TRUE AND FALSE AND TRUE, the first TRUE will be evaluated and then the FALSE will be...

Y no podemos cerrar la sección sin incluir las interfaces por voz. Si alguien es capaz de viajar al pasado, por favor, tened la delicadeza de no comentarle al autor que a la cosa aún le faltaban unas cuantas décadas.

English Recognition

The ultimate in user-friendliness

Plain English is hardly ever used to communicate with a computer. This is unfortunate because it can be very effective, and programs that recognize and use relatively complex English sentences have been written for microcomputers. English gives you a variety of ways to express complex actions with a minimum of training and program interaction. Menus, on the other hand, are often highly complex and cumbersome— both for the user and the programmer. Special languages are difficult to learn and to design and implement correctly.

Some applications seem to demand a natural-language controlling mechanism (for example, database programs and games). When you design these kinds of programs, it is hard to predict the questions or commands a user might enter. Even in the largest and most expensive custom database systems, there always seem to be questions outside the scope of the programming.

However. English has been used successfully to control database programs. The first public success was LUNAR (Lunar Sciences Natural-Language Information System), which allowed scientists to query a large file

of physical and chemical data on the lunar rock samples brought back by the Apollo 17 mission in December 1972. More recently. Larry Harris of Artificial Intelligence Corporation has been successfully selling a database retrieval system called ROBOT (now INTELLECT) that uses natural English. It runs on IBM machines and licenses for tens of thousands of dollars. R:base CLOUT by MicroRIM. another English-based database-retrieval system, runs on microcomputers, but it's not cheap either. Several game designers have recognized the benefits of using English to communicate with computers and have tried to use it as their controlling mechanism. However, the approach they take seems a bit limited. The games often have trouble recognizing what should be valid directions or questions by the players.

Nos vamos ahora al tema de portada:

AN OVERVIEW OF CONFERENCING 
SYSTEMS

by Brock N. Meeks

A guided tour through COM, EIES, PARTI, NOTEPAD, and other systems

NUOSO LIVES on the African continent. Exactly where he lives and the name of his tribe is not important; Nuoso is a nonperson. Convicted of a crime against his tribal society, he is forbidden to communicate with his family, his friends, in short, with anyone. His communication cut off, Nuoso quickly withdraws from the village. Eventually he will cease to exist even in his own mind, and he will literally die from lack of communication.

Just as people need food, water, and shelter, so they need to communicate. From the earliest days of history, our ancestors sought better ways to communicate. Primitive maps scrawled in the dust gave way to cave paintings, where information retrieval entailed nothing more complicated than remembering the right wall in the right cave. But just as society became more complex, so did the communication needs of the population.

Early telegraph links, in Napoleon's time, had signal speeds of about two characters per second. In 1913 vacuum-tube repeaters were introduced to telephony, and a rapid succession of advancements in the world of electronics followed. In 1918 the first carrier system permitted several voice channels to occupy a single pair of wires. The early 1940s saw highcapacity coaxial cables beginning to replace twisted-pair cables. Microwave links emerged in 1946 with the capacity to carry more than 10,000 telephone channels. Today's phone system uses satellite links and will soon use fiber optics. In a hundred years our communication capability has risen from fifteen to a billion bits per second, from two to over a hundred million characters per second. And all for the sake of improving communication with each other.

The Birth of Computer Conferencing

Early in 1970, political and economic pressures set the stage for the creation of a revolutionary means of communication. In the fall of 1971 the entire economic structure of the United States fell under the control of President Nixon's wage-price freeze. Because of the tremendous need to handle the reporting and information dissemination of the price freeze, the Office of Emergency Preparedness (OEP) commissioned Murray Turoff to create a computerized version of the "conference call." Turoff responded by developing the Emergency Management Information System and Reference Index (EMISARI).

The EMISARI system operated as an electronic network linking the ten OEP regional offices. The new price controls created a nationwide demand for information, guidelines, rulings, official statements, and policy clarifications from businesses, labor unions, and administrators. Because EMISARI eliminated the constraints of time and geographic location, the OEP's regional administrators were able to secure time-critical information at their convenience. The instant access of EMISARI allowed Washington to update policy as it happened and gave all involved the opportunity to respond or ask questions— with both...

Sí, era obvio, querida lectora, que no podíamos estar hablando de los Zoom de los 80, sino de los Discords asíncronos (a todo estirar, que más bien son Reddits lo que se menciona) que podían soportar los ordenadores y redes de telecomunicación de la época.

A destacar: (i) no aparece la palabra «Internet» en la pieza y, (ii) os podéis ir a la página 174 para ver una separata sobre los efectos que iban a tener estos sistemas sobre personas y sociedades. Si no me equivoco, por cierto, el firmante estaba, en aquella época, fundando el mítico The Well.

Volvemos a los anuncios. ¿Cuántos años le echábais a Logitech y sus ratones?

Anuncio del ratón Logitech LogiMouse C7

Vale, unas cuantas le echábais al menos cuarenta. Pero… ¿cuántas sabías que Logitech se dedicaba a los compiladores?

Anuncio del Modula-2/86 de Logitech

(Según la Wikipedia, Logitech se fundó en Suiza en el 81 con el objetivo de crear un procesador de texto, y de ahí se pasaron a los «roedores». En 1984 ya los tenían inalámbricos (por infrarojos). El C7 que tenéis aquí arriba era su primer ratón de venta al público. Vosotros también habríais pagado más de doscientos euros (actualizando la inflación) por tener uno, ¿verdad? Lo de Modula-2, parece ser, fue solo una veleidad temporal.)

No me iré sin darle un repasillo a los ordenadores de la época, c

Dos portátiles de la época y sus especificaciones.

Ambos pesan 4,5 libras (unos dos kilos).

El Tandy 200 tiene procesador 80C85 de 8 bits a 2,4 megahercios, mientras que el NEC PC-8401A tiene un procesador compatible Z80 a cuatro megahercios. El Tandy tiene 24 Ks de RAM, ampliables 74, el NEC viene con 64, expandibles a 96.

Tienen pantallas LCD, de 10 por 16 caracteres el Tandy, 80 por 16 el NEC.

Ambos tienen módems de 300 baudios. Se destaca que ambos tienen baterías.

El Tandy tiene un sistema operativo propio, el NEC es CP/M 2/2. Ambos vienen con suites de software que incluyen procesador de textos y hojas de cálculo.

¿Os habéis fijado que mencionan que ambos pueden funcionar alimentados por su propia batería? (Comentan del NEC, que con cuatro pilas tipo C (¿quién dijo «batería recargable»?) aguantaba un par de horas.) ¿Y que no hablan de ningún tipo de almacenamiento interno? No me molesto en calcular cuánto serían hoy los mil dólares que costaban, pero sí que comentan que el NEC, funcional, se va más bien a más de dos mil… Y también comentaré que la pieza se cierra con un «para qué un laptop» que, dada la tecnología de la época, era una pregunta más que razonable. Oh, los maravillosos ochenta.

Y cerramos con un clásico del software:

The Norton Utilities

Tools for recovering data and 
directories

Peter Nortons data-recovery tool really recovers lost data. I've used it successfully dozens of times. Will it save every lost file? No. Unfortunately, there are some kinds of damage that the Norton Utilities can't repair. Can you tell managing before buying the program whether it will help you recover a particular file? The answer to this question has to be inconclusive. There are different kinds of lost data, and sometimes, even when you know  how the damage occurred, it is difficult to predict whether it can be repaired.

The simplest kind of loss occurs when you delete a file by using the ERASE or DEL commands in DOS. Even though your directory indicates that the file no longer exists, it hasn't really been erased. What's happened is that an instruction prohibiting DOS from writing in certain areas of the disk has been altered. Your data is retained until information is actually written into these sectors. If you change your mind and decide that you need the discarded data after all, the Norton Utilities will reverse the changes made by the ERASE command and your old file will be restored.

Certain types of equipment failures can produce more serious data losses. Every DOS-formatted disk contains hidden files called the boot record and the file allocation table; these, together with the directory, are used for managing the data stored on the rest of the disk. If garbled information is entered into these files— a common cause is a disk drive out of alignment— your data may become inaccessible. But sometimes the data files themselves may survive this damage; if so, you may be able to recover some or all of them.

Retrieving Lost Data

If you plan to use the Norton file-recovery procedure, you should be careful not to write on a disk with a lost file. You'll risk having new data entered in the sectors containing the file you hope to save. Once the old information has been overwritten in this way, it can't be recovered.

If you did write on the disk, there's still a chance that the sectors holding the erased file were not the ones that received the new data; this depends on factors like how much free space was on your disk and which version of DOS you're using. So until you actually begin the recovery procedure, you won't know for sure whether the lost file was destroyed. Still, it's best not to take chances. Make it a rule to never write on a disk containing damaged files.

Another good idea is to make a copy of your damaged file whenever possible. If you're working with floppy disks, you should use the DOS DISKCOPY command (as opposed to the COPY * . * command); DISKCOPY works by reproducing what's on the source disk exactly, byte by byte, so even deleted data is copied. Carrying out the recovery procedure on a copied version of the damaged file means that if you make a mistake, you'll have a chance to recopy the original and try again.

After taking these precautions, you can begin the file-recovery procedures. In general, for simple problems like unintentionally invoking an ERASE command, you can expect the Norton Utilities to retrieve lost files consistently. When a problem is caused by a current spike, static electricity, or a disk drive out of alignment, it's harder to predict how much of a file can be recovered; this is because so many different varieties of error can occur.

With many types of errors, the Norton Utilities can often help you salvage something. At times you may be able to recover only portions of a file. This is similar to what happens when the CHKDSK procedure in DOS restores only some of the lost clusters (groups of isolated sectors) in a file. In many cases you can save enough of a file to be able to reconstruct the missing portions with little trouble. But for some files, such as those created with spreadsheet programs, even a small amount of data loss can

Las Norton Utilities del celebérrimo (y actualmente octogenario) Peter Norton llevaban el mercado desde el 82 (y quizás más sorprendente, se lanzarían versiones nuevas hasta 2012).

Como de costumbre, tenéis los archivos de la revista Byte en archive.org, y si queréis, podéis ir avanzando trabajo con el número de enero ¡del 86! Hasta el año que viene :-).

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!

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.