“You have probably heard of computer memory, and now we are going to see exactly what that is. Since the only thing inside of computers is bits, and the only thing that happens to bits is that they either turn on or turn off, then it follows that the only thing a computer can ‘remember’ is whether a bit was on or off.””
“Each pixel on the screen has a unique address consisting of two numbers, the first being the left-right or horizontal position, and the other being the up-down or vertical position. The address of the top left pixel is 0,0 and the bottom right pixel is 319,199””
“Everything you see a computer do is a long concatenation of these very simple operations, the ADDing, NOTting, Shifting, ANDing, ORing, XORing of bytes, Storing, Loading, Jumping and I/O operations, via the execution of the instruction code from RAM.””
“An Operating system also provides services to application programs. When an application program needs to read from, or write to the disk, or draw letters on the screen, it does not have to do all of the complicated I/O instructions necessary to accomplish the task. The OS has a number of small routines that it keeps in RAM at all times for such purposes. All an application needs to do to use one of these routines is to load up some information in the registers, and then jump to the address of the proper OS routine.””
“Then when one piece of metal moved to touch the other, the spider was in the way and they wouldn’t touch. So the electricity wouldn’t get to where it needed to go, and the machine would not operate correctly anymore. The fixit guy would remove the bug, clean up the contacts, and report “There was a bug in the computer.” And he literally meant a bug.””
“A byte is a location that can be in one of 256 states.””