Why is the speed of the CPU on board Pathfinder limited to 2.5, 5, 10, and 20 MegaHertz?
The speed of the Pathfinder computer is limited by the clock oscillator speed. The clock is divided down by 2s to get the next lower increment, hence the speeds of 2.5, 5, 10, and 20. We can’t run slower than 2.5 MHz because we can’t service the refresh rate on the 128 MBytes of DRAM and still have enough CPU to do useful work. During tests (with an external oscillator that can be minutely adjusted) we have tested the CPU at 2.5 to over 25 MHz in increments of less than 0.1 MHz. –Lloyd Keith, MFC Chief Engineer Back to the top of the page.
