Whether you're planning to build your own computer or you simply would like to know more about how computers of old and new work then this page is for you. First let me start by pointing out a strange occurrence that has risen with regards to the term 'PC' which means 'Personal Computer.' Actually, thanks to Microsoft, when most people use the term PC they don't just mean a personal computer but also, a computer that uses a version of Microsoft's Windows operating system (Windows 98, Windows XP, and so on).
I have used computers most of my life from back in the day of the microcomputers (for further information please see the Microcomputers section) that had just a built-in BASIC interpreter for programming to the more modern desktops and laptops running Windows 10, Linux and Mac OS X. So, like many others, I have seen computers progress from 8-bit, 1MHz, 1K RAM machines that could load programs from cassette tape right up to the present computers that are 32-bit (or 64-bit) running in the GHz's with multiple cores and with GB's of RAM, as well as hard drives able to store TB's of data. All of that may have made not much sense to you but the aim of this page is to teach how computers typically work, how to fix them and how to make your own simple computer.
The information on this page, I must mention, can also be applied to parts of a video game console, especially with regards to the first Xbox and more recent consoles (PS4 and Xbox One) having a very PC-like architecture internally.
New: Luckfox Development Boards (4/11/24)
Pine64 (26/9/24)
OKdo ROCK Computers (23/7/24)
BeagleBone Computers (19/3/24)
Tips and Tricks (22/01/2020)
NVIDIA Jetson Nano (13/10/19)
Intel Galileo (29/04/2018)
The Asus Tinker Board (13/06/2017)
Updated: Repairs (11/02/2015)
Updated: Computer Basics (28/03/2013)
Intel L1A4729 Memory Board
The Raspberry Pi (04/08/2012)
Create Your Own Computer
Repairs.
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You can email me at james.boshikoopa@gmail.com
You may wonder what is the most important part of a computer; the answer is debatable. The CPU (Central Processing Unit, such as a Pentium) is the brains of the computer as it executes instructions so without it the computer wouldn't start because there would be nothing to tell the other components what to do. Below is shown a wide range of CPUs:
From left to right:
Top row: 6x86MX PR233, Intel Celeron, AM486 DX2-66, Intel i486 SX.
Middle row: AMD Sempron, Intel Pentium (pin side up so that you can see the huge number of connections), Intel Pentium (top side), Intel Pentium (a different version).
Bottom row: Intel Pentium III, AMD Athlon 64 X2, Intel Pentium 4
Don't worry if any of the above doesn't mean anything to you. These CPU's were used in computers from about late 80's to 2000. The older CPUs (such as the Intel i486) were larger and heavier than the newer CPUs (such as the Intel Pentium 4). So, even as the CPUs got smaller and lighter they still got more powerful and faster. An important thing to remember is that actual chip that contains the circuit (as seen at the top of the CPU) is much smaller than the package but because there are so many connections the package has to be much bigger than the actual chip for all the pins to fit on.
Because these CPUs contain millions of tiny transistor switches that turn on and off at high speed a considerable amount of heat is generated when the CPU is in use. This heat can have a bad effect on the CPU and even cause it harm. To help safely remove the heat, a large piece of metal know as a heatsink is attached to the top of the CPU using heat conductive paste (the white stuff seen on one of the CPUs in the photo above). Especially with the newer CPUs, however, a fan is used in addition to the heatsink (usually fixed on the heatsink) to remove the heat quickly and better than the heatsink alone could.
To further help with reducing the amount of heat generated by a CPU, the voltage that a CPU runs at is now much lower than an older CPU. For example, most versions of the Intel i486 ran on 5V but the Intel Pentium 4 ran on 1.7V. The lower voltage means there is less current and heat is a product of voltage and current.
Another change over the years as CPUs have got more powerful is that newer CPUs contain multiple cores which can be thought of as a chip that contains multiple CPUs. This allows one core to carry out additional tasks while another core does something else. Software, however, has to be written to take advantage of these extra cores, such as the operating system which will divide up the tasks to give to each core. An example of a multi-core CPU in the photo above is the AMD Athlon 64 X2 CPU which contains two cores.
Before even CPUs came about with multi-cores, a big change that improved their performance was increasing the amount of data they could handle. The first CPUs were 4-bit meaning they could handle 4 bits of data, that is, 16 different values, which are transferred on the CPU's data bus. CPUs that came after were 8-bit and could deal with 256 different values. It should not be a surprise then that later CPUs were 16-bit, followed by 32-bit CPUs (such as the Intel i486) and more recently, 64-bit CPUs (for e.g., the AMD Athlon 64 X2 CPU).
Even with a CPU installed, without the PSU (Power Supply Unit) connected or working then nothing would happen if you tried to turn the computer on. Another very important part of a computer is the RAM (Random Access Memory), although the CPU has its own, tiny amount of internal RAM only a small amount of data can be stored there at one time so without the external RAM (external to the CPU) the computer wouldn't be able to do much.
A CPU must have instructions, the start up code, ready for it as soon as the power is turned on; these startup instructions are stored in the BIOS (Basic Input/Output System) which is stored in a ROM (Read Only Memory) chip. The BIOS of modern computers can be changed, such as to update it to provide new features or to fix bugs, however, this opens up the possibility of a corrupted BIOS which would stop the computer from starting.
The BIOS will check the system is running as it should and will display a limited amount of information about the hardware on screen, like how much RAM there is and if there are any errors. There will also be a setup configuration utility, usually accessed by pressing a certain button after power up, that allows the user to adjust settings such as the date and time, and what integrated devices should be enabled.
When the BIOS is checking the hardware it runs what is known as its POST (Power-On Self Test) and will test the RAM and look for connected peripherals, namely floppy drive, harddrive, CD-ROM and the like. As soon as it has done that and there aren't any serious problems, the BIOS will load the operating system (e.g., Windows) from the harddrive (or other device). The operating system can't be loaded first since, even if there were no need for tests, code either in ROM or RAM has to be available as startup code to load data from a peripheral like a harddrive.
Anyone who has had keyboard troubles or pressed a key on the keyboard when a computer starts up will be faced with the puzzling error message that reports a keyboard error and asks the user to press any key to continue despite the keyboard not working. The keyboard always has been for most computers the one input device you need more than any other but still that's no excuse for that stupid error message.
Please go to Microcomputers.
Please go to BeagleBone Computers.
Please go to Luckfox Development Boards.
Please go to NVIDIA Jetson Nano.
Please go to OKdo ROCK Computers.
Please go to Pine64.
Please go to The Asus Tinker Board.
Please go to The Intel Galileo.
Please go to The Raspberry Pi.
Please go to Create Your Own Computer
Please go to Repairs
Some programs, such as OBS, don't record useful information for a file such as its frame width and height, which should be accessible when you right-click the file in Windows' File Explorer and select Properties, then Details tab. You can, however, use a program to give you the information, and such a utility is Media info, downloadable from:
https://mediaarea.net/en/MediaInfo
After installing the program, right-click a media file and select Mediainfo; Mediainfo will launch with information about the video file. Alternatively, you could launch Mediainfo and then open a file (File->Open->File). For more detailed information about the file than what is shown in the default view select View->Tree.
I needed to convert an audio track from mono to stereo, in previous versions of PowerDirector it had the facility to call up the Wave editor to make changes to audio and was more featured than the Audio Editor built-in to PD 18, probably to encourage people to buy the (expensive) Audio Director. This means if you have, for example., a video with mono audio in it that you want to convert to stereo that can not be done in PD 18. However, if can be done in an external program, such as Audacity..
Start Audacity (I used V2.3.3) and open your video clip with mono audio: File->Open... Select the video clip and click the Open button. You will likely see two tracks but one of them is blank. To the left of the Audacity window you should see to the side of the two tracks the name of the video file and a small black arrow; click it and select Split stereo track. Delete the blank track by clicking the arrow to the left of the track (to the side of the video name).
You will have one track remaining; clean up the audio or do whatever else you need to do. Then Ctrl + A to select the whole track and go to Edit-Duplicate. You will have 2 tracks but you need to make sure that one is for the left channel and the other is for the right channel. To do this check that the L.....R slider to the left of each track is set to L for one channel and R for the other by sliding the control all the way (doesn't matter which is set to left or right). Next, go to File->Export->Export Audio... Give the file a name and click the Save button.
In PD, after inserting the video clip with the mono track right-click on the track and select Mute Clip. Import the audio track from Audacity and drag it under you video clip so that the start of the audio track lines up exactly with the start of the video clip. You should now have you video clip with stereo sound.
I was working on quite a large project and whenever I imported audio files the waveforms wouldn't show. I created a new project and found that any audio I imported the waveforms showed. Reopening the previously mentioned project, the waveforms now showed. Also, on a related note, the waveforms won't show if the track isn't vertically big enough, drag it higher to see the waveform.
While computers of today have plenty of RAM, with values in the GB the norm, back in the earlier days of computers the size of the RAM was more in the MB. I had acquired this Intel memory expansion board (as seen below) and thought I would share it with you as it's a good example of how vastly technology has advanced since it was made.
Unfortunately I can find very little information about this board. What I do know is that it uses a 16-bit ISA interface and was used in a pre-Pentium computer possibly from the early 90's. The large square chip in the middle, a L1A4729, is likely to be some form of memory controller. As for the RAM, there are X18 TMS4256-10NL DRAM (256K x 1 bit) IC's and X54 MT 1259-12 DRAM (256K x 1 bit) IC's. I don't know how the RAM chips are connected but if all of them are added up, those 72 chips would total just 1MB of RAM! To think you can now buy a small memory stick of 1GB or more yet the board above is the size of a modern graphics card which may have 12GB of its own memory.
All content of this and related pages is copyright (c) James S. 2007-2025