From: Dave Arnett I try not to establish too serious a tone, but the gist of my post was factual. I did put the jumpers on the board for this very reason. There are other jumpers on the board, as well. Why did I do it? 1. We were not certain whether there would be a demand for the 48SX after the G and GX were introducd. I have jumpers on the board which would allow you to build an HP48SX on this circuit board. That task requires rerouting the card detect and select lines and (optionally) running the CPU at 1X speed rather than 2X speed. 2. There were problems with the yield of Yorke ICs from NEC which would run at 2X speed at all temperatures. We had a contingency plan that would have made all HP48G units run at 1X speed until the problem was resolved. The jumpers allowed us this option, had it been necessary. Thankfully, the yield improved and we didn't have to exercice the option. 3. The old RAMBOX development systems used by the software team would only support 1X operation. The ability to select 1X speed when runnig code from the RAMBOXes, and then switch to 2X speed when running from the EPROM was a design requirement. I saw no reason to delete this feature on the production board. My EPROM unit and Charlie Patton's unit had a gearshift for switching speed on the fly without a slodering iron. Good Day! Dave. ------ I don't speak for HP when I post here.