Chapter 79 Fire

In history, the first APPLE_II computer was launched on June 5, 1977. It is equipped with a 1MHz 6502 microprocessor of MOS Technology, with 4KB memory and a tape interface for reading programs and data.

4K memory? Recording tape data storage?

There is no doubt that the memory at that time was indeed only 4K, which was much larger than the first generation of APPLE.

The principle of using tapes as a storage device is similar to that of music tapes, but music tapes store analog signals, while data tapes store digital signals.

However, the machine in Lin Hong's current hand stores data instead of a recording tape, but a 5.25-inch floppy disk. This is an improved model in 1978. The external 5.25-inch floppy drive DISK_II has replaced the tape. This is a genius design, and the reason why its manufacturer Steve Woznik designed such a thing by himself was entirely to save money and cost, because they were When I started a business, I was so poor that I didn't even have enough money to buy a product made by myself.

"Save money" is an important design concept of APPLE_II. Woznik uses many whimsical and ** engineering techniques to achieve the whole purpose. The components used in this machine are the least, cheapest and the most common on the market.

For example, the machine's text and image system used an outdated connection method at that time. It is said that Woznick believes that this can save a chip, and it will be cheaper to address with software or scan lines than to add hardware control. Similarly, in the high-resolution image mode, the color is determined by the pixel position, so it can be controlled by software, which saves the cost of converting the chip.

However, after the computer was launched, it quickly became popular all over the world and became the first personal computer to achieve great commercial success, which was sought after and improved by many computer enthusiasts.

The "Red Book" is about 70 pages not thick, but Lin Hong read it slowly and carefully.

Although he has installed a primary English-Chinese dictionary in his mind at this moment, there are still some words that he does not recognize, which are basically some new professional words and abbreviations that have emerged in the past decade.

However, this does not affect his reading. He has some abbreviations of professional words, and he can even guess the general meaning of other words according to the context.

This manual is divided into four parts.

The first part is naturally a basic introduction to this computer, which is the content for the vast majority of users.

The second part introduces the INTEGER_BASIC programming language that comes with APPLE_II. This language is optimized and redesigned by Woznik on the basis of a language called TINY_BASIC. Although the syntax is similar, the operation speed and function have been greatly improved. When Woznik was designing, he burned the program of this language directly into the ROM (read-only memory) of the machine, so that even if the system is reinstalled, the BASIC language is still in it and will not be lost.

The language content of this part is very detailed, with not only basic grammar and rules, but also some program examples, so that beginners can enter them according to the code.

Many programs in this period require beginners to type in letter by letter to see the effect. This is the fun of computer enthusiasts, but this is obviously just a niche hobby. Most people don't matter at all. They have to sit in front of the computer for half an hour to enter such a large piece of code, and then the final result is just drawing a few circles on the display, which will make them crazy.

Parts III and IV detail the firmware and hardware of APPLE_II respectively.

Firmware is a program written into EROM (programmable read-only memory), and the popular understanding is "cured software". To put it more simply, firmware is the software of BIOS, but it is completely different from ordinary software. It is the program code solidified inside the integrated circuit and is responsible for controlling and coordinating the functions of the integrated circuit. For example, there is such a solidified system software in the display controller, which can be programmed to operate the display, change the color, and draw lines on it.

I have to say that the content covered in this book is so detailed that Lin Hong is completely trapped in it.

The radio technology he came into contact with before is completely a circuit entity at the physical level. Even if the radio wave cannot be seen with the naked eye, it is also a real thing that can be monitored by equipment.

However, the software he came into contact with today is an invisible thing.

Software, like language and writing, was invented by human beings.

What makes him feel most wonderful is that the operation of software is based on hardware.

Software has become a bridge between people and machines. If there is any problem with the machine, you can "tell" the operator through the software, and if you want to operate the machine, just "tell" the software directly.

Lin Hong thought about the difference between humans and animals in his spare time in the evening.

When he was a child, under hearsay, he thought that the soul really existed, but when he mastered more and more knowledge, he read more messy miscellaneous books and gradually understood that the soul did not seem to exist, at least no one has ever confirmed it.

Although he has never systematically learned about biology, he is also vaguely aware that language and wisdom are important factors that distinguish human beings from other animals. And gradually formed a relatively vague cognition. He felt that language and wisdom were equivalent to the human soul.

Today, when he learned the basic principles of software, a similar idea suddenly came to his mind - isn't software the soul of the machine?

This idea is still very vague, but there is a flash of inspiration in his mind, and there is no theoretical support at all. It's just his feeling.

However, this is a small kind of fire. From now on, it has been deeply stationed in the bottom of his heart. Since then, it has grown with his growth, and finally formed the momentum of igniting the prai... Of course, this is the last word.

There are a lot of circuit diagrams and basic principles in the firmware and hardware part. Lin Hong didn't have a clue for a while and couldn't fully understand it, so he just scanned it briefly. He is not in a hurry now. After he has familiarizes everything in front of him, he will go back and study it carefully.

While he was reading this book, Sun Wu called halfway. The two chatted for a while on the phone. When Sun Wu heard that Lin Hong might follow his mother to visit Beijing in the next few days, he immediately urged to go together. His father didn't have time to accompany him to Beijing. After the two agreed on the time, they hung up the phone.

Although Lin Hongcai used the phone for the first time, he did not have any psychological obstacles. You know, he used to make free "international calls" every day. In his eyes, the phone was simply too simple.

He looked at the time and it was almost five o'clock, and his mother had not come back from shopping.

He had been hungry for a long time, so he had to go to the hall and eat the apples he had put on the table before, and put his stomach on first.

Now everything is ready, only the east wind.

He came to the desk and started APPLE_II again. After the sound of "beep--" sounded, the previous picture of green words on a black background soon appeared.

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It's time to rush to the list again. Xiaoqiang's new book list was on the list after only ten days, which is very sad. I want to try to click on the list tonight. There will be another chapter after twelve o'clock in the evening. Please hold it up, click + vote ~ rush up and add updates

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