6502.org

Hi Garth,

I understand that in a life or death situation, you may want to bring the clock speed down for reliability. But the board has been tested for quite some time, with both 6Mhz and 2Mhz crystals with flawless operation. The board comes in a kit form, and if the user is concerned, he or she can use a smaller crystal, or simply use the jumper to select between the 2 or 6 mhz settings. This is an experimental board meant for education. It is NOT intended for use in harsh environments of any kind. But if you were to use it in a harsh environment application, the clock speed is selectable via jumper.

FYI, the board also has a voltage regulator, so varying voltage levels from a power supply shouldn't affect it. As well, we ship the board with a powersupply that has been tested with the board.

Well, again, you are depending on actual times being better than the specified times. It's nice to know however that they are that much better; but it does mean that at any time the suppliers could give you slower parts that are still within spec and they won't work at your speed and it won't be any fault of theirs.

That is usually the case with most parts. They always publish the worst case scenario.

Professional Test Engineers work towards 100% reliability for their company's devices, and willingly test such parts to destruction for non-functionality. Sounds like you may be riding the 90% wave or so, optimistically speaking, no offense...

Good luck!

Like I said. The board is a kit that you solder together. If you do not want to use the 6Mhz crystal, you can choose from all kinds that are available. 1,2, 3, 4, 5 or anything in-between. You are not forced to use th 6Mhz. There is nothing on the board that expects a 6Mhz clock. You are given full schematics with the board.

If you would like to experiment with other logic setup, different ROM's, you can create your own on a breadboard and connect to J1. It is an educational experimental board.

We are in the process of designing the NCS-VM256 which will be a simple video and memory board to be plugged into the NCS-EB50. Again, it is designed to teach. It won't be the biggest baddest video board ever built, but it will be fun to play with, and very educational.

Got one, nother side project. Will relate as I go on with it. Still working the pinball as well...