: Details the "contention" that occurs when both the CPU and ULA attempt to access the lower 16K of RAM simultaneously. I/O Handling
Why? Because one engineer, armed with a logic analyzer and a Ferranti databook, looked at the problem of building a color computer for the working class and said: "I don't need a million transistors. I need 1,000 gates, configured perfectly." : Details the "contention" that occurs when both
They hooked up an oscilloscope. The jagged line of a signal danced across the screen. They realized the ULA was struggling to keep up. When the Z80 tried to access the memory at the exact moment the ULA was reading the screen, a collision occurred—a "contention" error. I need 1,000 gates, configured perfectly
Because the ULA is too dumb to multiply. When the Z80 tried to access the memory
To the naive observer, slowing the CPU down 30% to draw the screen is a flaw. To the systems engineer, it is genius.