Hello Allen, >I have been messing with computers since TRS-40, TRS-80 and Coleco. >Being old but not too "smort", I have not been able to follow the operations >inside a computer. Most explanations seem to start off with too much >detail. Are there any "black box" explanations for, say, what happens in >a boot operation, modems operations, midi etc. The boot process is called that from the saying "pulling yourself up by your bootstraps". Boots used to have straps that you pulled on to get them on. The boot process is pretty complicated, so I'm probably going to miss something along the way, but here goes. When you first turn the power on, the computer first verifies that the power is good, meaning that all of the voltages coming from the PC power supply are within the operating range of the system. After that check happens, the CPU begins processing. The first thing it does is to look at a specific memory address, which is normally at the end of the ROM space. Normally, this address contains a command to jump to another specific memory location, which varies from system to system, which is the start of the BIOS program. BIOS stands for "Basic Input/Output System", and is a program that is hard wired into a special chip on your motherboard. This checking a specific memory location, and then jumping to another memory location based on the information stored there, is technically the entire bootstrap operation. However there are more steps that the computer takes that everyone normally considers part of the process as well. When the CPU starts running the BIOS program, several things are done. The first thing that usually happens is the POST, or "Power On Self Test". The POST consists of a number of checks of core system components, including checks of the CPU itself, the math co-processor (if present), and other major chips. You usually will see a visual indicator on the screen when the BIOS is testing the memory. The BIOS then queries the system to see if there are any other device-specific BIOS chips, such as drive controller BIOS chips and so on, in the loop. If so, it methodically runs through any startup routines found in those chips. Next the BIOS looks through a specific memory area for a video ROM. This memory range is set aside for this purpose, and nearly all systems will have a video ROM in that address range. If a video ROM is found, control is transferred to it so it can initialize the video adapter. Up until this point, your screen has been blank. If the video subsystem initializes correctly, you'll start to see the boot screen at this point. This is where various information is displayed, such as the maker and version of the BIOS and possibly a company logo and so on. Control is then transferred back to the BIOS and the memory test begins. You normally will see this memory check displayed as rolling numbers on the screen. After the memory check is finished, the BIOS looks for an operating system to load. There is a specific place on properly formatted hard disks, called the MBR, or Master Boot Record. The BIOS looks at the MBR to determine where to start loading the operating system from. It then loads the operating system, and transfers control to it and the boot process is complete. Modem stands for "Modulator/Demodulator". The normal phone lines, also called POTS for "plain old telephone service", and traditional telephone equipment is analog in nature. Analog equipment operates on continuous electronic signals. Analog signals change in voltage smoothly up and down, and information is contained in the speed and frequency of the changes. Computers are digital, which operates in discrete chunks of information, either "on" or "off", with no changing middle ground. What a modem does is, it takes a digital signal and converts it to analog and vice versa in order to allow the digital device of your computer communicate with the analog device of the POTS lines and equipment. Midi I know little about, except that it stands for Musical Instrument Digital Interface, and that is a standard that is designed to facilitate recording of music played by live musicians on traditional instruments on digital recording equipment on digital media. HTH, Ron - Users can unsubscribe from this list by sending email to 24hoursupport-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field OR by logging into the Web interface.