CompuServe Messages

Bill, It's difficult to know how GVP approached the design of the board. If they spec'd all the "common" chips to run at the fastest clock speed they might install on the board, then changing the oscillator and CPU/FPU to run faster might just work fine. On the other hand if that's not the case, then you could have problems with either some chip failing (worst case) or erratic performance. Most chips can be run somewhat faster than their design frequency, but I think the "rule of thumb" is about 10%. Going from 40 Mhz to 50 Mhz is a 25% increase and it's likely that any clock sensitive chip will not run reliabably that much faster than it was designed to run. My advice is don't make that change unless GVP tech people explicitly tell you it's OK and will work. If the board is still in warranty, such changes will certainly void the warranty. On the other hand, replacing the 40 Mhz 030 and 882 chips with 50 Mhz chips should present no problem because they will be running well below their design frequency at 40 Mhz. If you later find that using a faster oscillator is possible, it wouldn't be much problem to make that additional modification.