Letting the list know that I have found a couple of defects with QUAD V4 which I did 2 years ago. Here's the defects I found.
1) I did not protect the bank switching function adequately. The M100 OS will periodically write to ports 80h, 82h and 83h wrt the DVI. This can cause V4 QUAD to change banks. 2) The power up/power down behaviour wasn't adequately protected, and there was a chance that RAM could be corrupted and/or banks switched on power transients. 3) I was using the wrong timing to provision banks. Not too good. In fact I believe this is the source of the frustrations I was having integrating QUAD with REX Manager. The good news is that I have prototyped a QUAD V5 which addresses these defects. The changes: * I have added a MOSFET based "activity switch" that allows RAM and bank switch protection on power transients * I have improved the bank selection circuitry to be robust on power transients. * I have changed the bank switching commands to make the mechanism more robust. * bank switch state is now preserved during power transients. I'll report back on how well these changes work out when I get boards back and have them tested. In the meantime, I've taken QUAD V4 off of OSHPARK. cheers Steve
