gemini@homxb.UUCP (Rick Richardson) (11/23/85)
This may have been said before, but I might have missed it. I just installed an 80287 into my AT, and discovered that the socket for the 80287 was installed *BACKWARDS* by IBM. That is, the cutout indicating pin 1 on the socket was placed at the back of the machine, instead of the front. If the chip is installed by looking at the cutout, the machine will (naturally) not operate. Reversing the chip and ignoring the cutout made things work. Apparently, the power/ground on this chip are not on pins 40/20. Thank goodness, I'd have hated to burn this baby up! The Guide to installation shows a correct picture of the way things should be, but I didn't look at it, thinking that I could just use the socket to get things right. Oh, the speedup? Running 16 Mhz crystal, last years taxes took this long to recalculate: NO 287 WITH 287 REAL 19.0 7.0 USER 4.5 4.8 SYSTEM 13.1 0.6 Considering that I got this chip from Intel as part of the MDK-286 design kit for $99.00, I'm happy. Rick Richardson PC Research, Inc. ..!ihnp4!houxm!castor!rer [don't reply directly to this article]