! >>Sounds like a 486SX/25 system upgraded to a DX2/50 with an ! OverDrive chip. ! > ! >Or somebody stuck in a DX-50 and its just running at 25 MHz. I ran an Evergreen test program on it last night. It said it was running at 50MHz, internally? ! If the chip inserted into the other socket is a plain DX-50 ! then it would be just running at 25mhz. The insertion of the DX-50 ! or a 487 'coprocessor' would've disabled the SX-25 as well, if it was ! left installed. Too bad the DX-50 got such a bad rap for heat ! problems early on. ! ! BTW, does anyone know how the mainboard tells the difference ! between the 486SX and a 486DX/487? Just looking at them, there ! aren't any pin differences externally, at least between the 486DX-33 ! and 486SX-25 I have sitting here. IIRC, it's how you set the jumpers for the clock multiplier, for the speed; and it does some sort of detection test for the numeric processor. I think... These clock speed jumpers are what I'd like to identify first. I have a DX4/100 just sitting here. Then, I want to identify the purpose of the other 20+ jumpers on this board... --- David A Woyciesjes --- C & IS Support Specialist --- Yale University Press --- mailto:david.woyciesjes@yale.edu --- (203) 432-0953 --- ICQ # - 905818