I received today another set of simms, and took out my collection of boards to test them. I own a 386/40 board, which is very small , and whose main disadvantage is that it has only four simm sockets. The CPU is soldered on it, and the chipset is MX. So, while playing with it, I noticed two jumpers, JP1 and JP2. It says that if you short just JP1 it works @40MHz, and if you short just JP2 it's @33MHz. I tried to leave both jumpers open, and I measured the speed, which was 25MHz. Then I though to leave both open, and it was running @16MHZ! I'm using the landmark speed test, which in addition to the actual cpu speed, it has also an AT speed, which means that you need an AT running at this speed to match your machine's speed. When running @40MHz, and with cache memory enabled it says it's like an 69MHz AT. The results may vary a lot according to the actual cpu speed turbo and cache setting, and @16MHz and with cache and turbo off, it is like an 7MHz AT... I like also the fact, that you can change the cpu speed while running, without having to turn of the machine. As a matter of fact, it turns on only while running at 33/40MHz, otherwise it hangs. I'm thinking that if I can make something with two switches that are accessible from outside of the pc, it might be the ideal board for very old dos games.