Saturday, May 19, 2018

The MOS 6502 CPU microprocessor

In the early '70s, a group of engineers from Motorola was convinced that it was possible to obtain a cheap microprocessor if a simple design and an improved manufacturing process were raised with respect to the standards of the time. Without the support of the company, this group would create one of the families of chips that would be the catalyst for the revolution of home computing, it is the 6502 and its successors, the main engine of the first Atari and Apple machines, between others.

Chuck Peddle was one of the leading engineers in the development of the Motorola 6800 processor, in his meetings with important industrial clients, he realized that the technology was appreciated, but too expensive to be used in a massive way. In conversations with his clients, he concluded that the cost of the processor had to go down from USD $ 300, which cost 6800 to only USD $ 25 at the time, a conclusion that did not make Motorola managers who had no motivation at all happy. to look to reduce the price of a technology that already had good sales.

Chuck Peddle and his work

For Chuck and other engineers it was an interesting technical challenge and without the support of Motorola they began to work on the necessary changes to improve their processor. On the one hand, the team was unhappy with Motorola's lack of support, and on the other hand the company was annoyed by Chuck's and his team's stubbornness, and finally the straw that broke the camel's back was Motorola's formal request to halt the project. that made Chuck and his team decide to leave the company, to continue working on their microprocessor on their own.

6502 CPU chip (C) commodore.ca

MOS

The group joined a low profile company called MOS, where they reached an agreement to participate in the profits that could be obtained with the new microprocessor, an agreement that from the MOS point of view was convenient due to the low profitability that meant in that time the production of these chips. This agreement, together with the mass resignation of Motorola was a demonstration of the confidence that the team of engineers had in the product they were developing.

The first processor of the 6500 series was 6501. An unprecedented fact that surrounded the development of this chip was that Chuck designed it completely by hand and it worked on the first attempt, when the normal thing in those years was to go through a process of over 10 failed attempts This processor was quite scarce since it was not made in order to be sold, but as a way to show Motorola how wrong they were, and that a useful and inexpensive microprocessor could be built.

One of the factors that influenced the reduction of production costs was an innovation of these engineers regarding the manufacturing process. In those times, the failure rate in production was 70%, that is, only 7 of every 10 processors manufactured went straight to the trash. This happened mainly because the process consisted of creating a large mold of the processor and applying reductions until reaching the real size, in these reductions errors always occurred and the engineers in MOS found a way to apply corrections to the mold in each reduction, achieving with this change a success rate of 70%, that is, 7 out of 10 processors were perfect.

The 6501, a Motorola clone?

The 6501 was fully compatible with the Motorola 6800 boards and could be used as a direct replacement at hardware level, which motivated a Motorola claim for alleged patent infringement of its former engineers. Supposed because in fact what was at stake was the intellectual property, since it was applying the knowledge of technologies that in fact were not patented. Even so an agreement was reached with Motorola and a sum of about USD $200,000 was paid to end the lawsuit.

The problem with Motorola caused the creation of the 6502, it was a 6501 but incompatible with the hardware designed for the Motorola 6800. The 6502 debuted at WestCon 1975 at the exact price of USD $ 25 that had been proposed. At first the attendees thought that it was some kind of scam, since it was not conceived to create such a cheap processor, but on the same day Motorola and Intel lowered the price of their 6800 and 8080 processors from USD $ 179 to only USD $ 69, validating the 6502 that was sold by the hundreds.

In the coming years Commodore, who was still in the calculator business, was going through financial difficulties as the business was going down and the competition was getting stronger. As a strategy to change the direction of the business, they bought from MOS, which was also struggling but had the technology they needed.

For Chuck Peddle the microprocessor business was geared to the industrial world, but while visiting different companies to try to sell the 6502 they told him that a couple of guys were trying to use their processor to build a personal computer. The fact seemed nice and agreed to go to help them to his garage, it was nothing more and nothing less than Steve Jobs and Steve Wozniak who worked on his first Apple computer. Chuck thought about introducing the 6502 into the industries and he did not suspect that a big market was in personal computers. Not in a million years! In his own words.

The 6502 is an 8-bit processor, which means that all its internal operations handle numbers between 0 and 255, on the other hand it has a 16-bit address bus that allows it to access up to 64KB of memory. The 6502 normally operated with a clock between 1 and 2 Mhz but given the same clock frequency it was capable of running much faster than the Motorola 6800, thanks to its clever design that reduced the number of clock cycles needed to execute an instruction .

Among the computers that were built around the 6502 are the Commodore PET, VIC-20, Apple I and II, BBC Micro and the entire line of Atari 8 bit computers such as the XL, XE, 400, 800, but also can be found in other types of devices, such as the Commodore 1541 disk drive for Commodore 8 bit computers. In the pioneering Atari 2600 console, an economical version of the 6502 known as 6507 was used, a version that had fewer pins and could only access 8KB of memory. The Commodore 64 also used a modified 6502, it was the 6510 where it added simple features that were usually implemented with additional circuitry.

Saturday, May 12, 2018

Fast weight loss with reduction diets?

Losing body weight with a reduction diet

Find your right diet plan

Origin of the term diet

The term diet comes from ancient Greek δίαιτα díaita and was originally used in the sense of lifestyle and the way of life itself. Dietetics is still scientifically concerned with the "right" diet and lifestyle. In the German-speaking world, the term refers to certain diets and diets that are intended either to weight loss or increase or to treat diseases. In the English-speaking world, diet is understood as the everyday diet of an obese person, regardless of weight-related or illness-related diets. Colloquially, the term in Germany is often equated with a reduction diet for weight loss. It is thus a synonym for slimming diet.

Types of diets

Lose weight - (C) GideonSince Hippocrates diet is a special diet of humans, in the longer term or permanently a special selection of food is consumed. The diet is either a short-term change in the diet for weight loss, for example to fight obesity or to remove belly fat, in some cases also to gain weight like anorexia or a longer-term to permanent dietary change to supportive treatment of a disease (like in celiac disease, lactose intolerance, fructose intolerance. Fasting, on the other hand, means the temporary abandonment of food from religious (in Ramadan Islam, pre-Easter Lent in the Christian church) or health motivation for fasting.

Any form of diet, whether for weight loss or supportive disease treatment, is based on a reduction or increase in the relative proportion of a nutritional component (carbohydrates, fats, proteins, vitamins, minerals and preservatives) over the others and / or a reduction or increase in the intake total energy and, if necessary, a balanced change in fluid intake.

A more holistic approach is cognitive behavioral therapy used by psychologists in clinics to treat obesity. In this method, dysfunctional behavioral routines and eating habits are identified and retrained. In case of severe obesity and eating disorders, it is the most sensible method of weight loss in the long term.

Fast weight loss with a reduction diet

A reduction diet aims at losing body weight. There are numerous reduction diets, some of which differ considerably in their methods. Only a few diets have been scientifically tested. The development and promotion of the reduction diets is not only subject to changes in scientific knowledge but also to fashions and worldviews. Some forms of diet are even considered harmful to health in medicine.

Reduction diets should be given only for a short time (and for extreme forms only under medical supervision). The general consensus is that a reduction diet can only be successful if it is followed by a permanent change in diet in which the energy balance of the body is balanced, d. H. in which no more energy is supplied via food than the body needs. A change of life towards a full-fledged diet and increased physical activity is recommended. When relapsing into old eating habits and habits, it usually comes back to a rise in body weight, the so-called yo-yo effect, because you fall into old eating habits that are not adapted to the new lower body weight.

There are numerous diets with different concepts. These are for example low-carb, low-fat, food combining or glyx diet. In a study of mice conducted by the Institute for Nutritional Research, there is a connection between the consumption of fructose and obesity, which is not based on the increased energy intake, but on the fact that fructose affects the metabolic activity and thus the accumulation favored by body fat. The selfish brain theory, which also includes an approach to explain obesity, does not question the short-term effects of reduction diets, but their long-term success in principle.

Does fast weight loss with a reduction diet work?

In short it pretty much depends if the person really wants it. There is no wonder pill. The person has to work on it. The own will needs to be strong enough to go through it. Otherwise there is no weight loss, only losing the fight.