The information on this site is presented for EDUCATIONAL Use only. To promote education of the electronics commumity based on the concept to develop the electronics of the future one must also know the past. People in the past were not stupid. They did what they did with far less information and built the industry infrastructure from nothing. They actually did a lot of pretty amazing stuff with what they had. The Web site creator has found many ways of doing things that are quire simple where these days there would be microcontrollers and firmware involved. The site creator are not saying thise ways are bad as they have used those themselves in creating some of the things they developed over the years. SAFETY WARNING This site is only for those who already have training in electrical or electronic safety when dealing in voltagess over 30V. The circuits in this site may operate at high voltages and currents. IF ONE IS NOT 100% COMFORTABLE, EXPERIENCED AND SKILLED WORKING SAFELY WITH OFTEN LETHAL VOLTAGES AS WELL AS HIGH CRRENTS THAT CAN START FIRES THEN ONE MUST LEAVE THIS SITE IMMEDIATELY AND NOT ATTEMPT CONSTRUCTION OF THEM. No responsibility is taken by this web site or its creators for any issues concerning any of the information on this site. Nor for effects for subsequent damages caused from use of this information in any manner for form for any reason whatsoever. Amateur users whi decide to try constructing these should only use circuits that operate on 40 VDC or 30 VAC or less. In each section there are basically two areas: Circuits - Where information is mainly oriented towards the design and building of electronic circuits. Products - Where the interest is mainly in product repair or operation. If the letters "OM" are in the title then this is only an Owner's Manual and there is no schematic. Much of the material presented here is old and especialy the computer related and video stuff is quite obsolete. However it is not possible, when moving into the future, to avoid the mistakes of the past without having knowledge of the past. Through some of the material here you can see the evolution of the technology. In other cases, the material may be old but the fundamentals are still the same. I know full no one is going to build a project like a Picture Phone from 1982 or the like. But often it is easier to understand the basics from looking at an old design using discrete components or small scale integration ICs rather just having a VLSI chip and having no knowledge on how it works. These magazine articles are what taught me a lot of my trade that made me into a successful engineer. It is a sign of excessive pride to think you cannot learn from what has been done before. I have used things from articles dating back to 1946 in some of my work. As well, if you do want to build a project these older circuits often have parts that are readily available while a newer design may have application specific chips that are no longer available. ESPECIALLY MICOCONTROLLERS THAT HAVE FIRMWARE IN THEM. Microntrollers that are offered pre-programmed for projects are rarely available for over 2 years from publication date. You MUST VERIFY that all parts, especially ICs are still available before starting. Especially programmed parts like microcontrollers, sensors and FPGA chips. The goal here is education. Even reading how a circuit works, even though you cannot get the parts to buildit can teach you a lot if you want to design new things later. This has served me well over a long career of over 50 years. On any build it yourself project use a site like one of these below to verify the parts are still available. Especially ICs: digi-key.com mouser.com octopart.com In my long design career it is amazing how often I have been able to save a great amount of time just using a section of one of these files rather than doing it from scratch. After all, what has already been published is known to usually work. Other good sources for building blocks to incorporate into new designs are manufacturer's spec sheets application notes and the documentation for the demonstratin boards from the manufacturers. Often these are called Product Development Kits. While having those kits (PDKs) is great just the documentation can be very handy as they give you examples of what is known to work already. You just have to emiminate the parts you do not need and add on what extras you do require. Do note all of the material on this site is in the following categories Service Manuals for out of production equipment Complete text books Articles extracted from older magazines that were available for free download on the Internet The text books were all found on free sites all over the internet which implies the copyright holder has abandoned them. Some are from known defunct publishers and it is unknown by this site administrator if anyone now owns the current rights to them. As it is not the intention of this site to deprive anyone of revenue from any sites requiring payment for material, none of the material on this site was acquired from any site that charges anything for downloading. If I can find something for free download on the internet, that is obviously not a pirate site, especially at a site like archive.org, I consider it fair game unless the publisher tells me to remove it. If you are a copyright holder for any of these files and object to them being here, please indicate such in an email to me at chuckles951@yahoo.com and they will be removed as soon as possible. But you should also be nagging the people who originally posted them. Most of these were downloaded from the free downloads available at archive.org then gathered together in one convenient place for the electronics community. Magazine articles were either scanned from magazines no longer being published and were the site manager's own purchased copies or they were extracted from older editions of magazines that were downloaded from free web sites such as archive.org then the relevant articles sorted for the convenience of the electronics community. There should not be anything here which was published less than 5 years ago as there is no intention of depriving anyone of revenue. Because without revenue, new content will not be created. As an electronics engineer in 2018 when I write this, I never thought I would be working for a company that was developing new vacuum tube power amplifiers and pre-amplifiers. Though through the 2000s when I was in California I was developing hardware for PWM power amplifiers and 32 to 64 channel digital audio distribution for large venue professional audio systems. From working on the bleeding edge of technology that was not even science fiction when I was learning this profession and then called upon to use what I learned in the late 1960s in high school. I was among the very last to get their basic electronics education on vacuum tubes. I have even done neat things with technologies from even before my time that are virtually unknown now like using a magnetic amplifier to control the brightness of flourescent tubes. A home made magnetic amplifier using standard 6.3V transformers and a pot to create a magnetic amplifier. Now, having been in this business since age 15 and retiring in 2018 with 51 years direct experience in electronics I am hoping to be able to find the time to update the file names where many are confusing and to incorporate a lot of the remaining material I have so it will at least be archived. However for various reasons time is still not as abundant as I expected. Between online groups and other things (though my TV watchinng is limited to only a few specific shows) and that 10 AM has become the crack of dawn for me, I am getting updates done a lot more often. Once there was about an 8 year hiatus. Now I hope to have one every couple months. What is new for this update and the last 3 or 4 updates are listed in the root directory below the home page. Maybe someone will write a script that can extract just the new files listed in one of these txt files so people will not have to doenload the entire web site regularly. If you do write such a script, I would like a copy. Send it to me in a zip file to chuckles951@yahoo.com. Please enjoy looking at the past of the electronics world as there is still a lot of proven stuff here that is likely to work very well if you build it or use bits of in new designs. After all, we build stuff to learn more so we can design new products. Yes you can buy almost anything you want but I believe it is only by building things that you truely learn design. There is nothing like making the first prototype of a new product design work to really make you understand exactly how the design works. The electronics world has been kind to me, allowing me at age 49 and nearly broke after a divorce, to supply me with the capital to invest well for a very comfortable retirement. Other than at school, I learned much of what became my career from what came in the magazines every month. The old magazine articles that are all over this web site. Yes, I have lots of newer material but I will not put up material from sources I know are still in business as that would violate not only the letter of copyright but also the spirit of it. Besides, these sources generally have their older material already available online and I see no point to duplicate their efforts. Updated September 2023 Chuckles British Columbia, Canada