chymes@zug.csmil.umich.edu (Charles Hymes) (03/11/91)
---------------------- The PD I/O expantion board I just built dosent work, and the current thing to try is to replace the chips. The board uses a R65C22p1 CMOS VIA, a R65c52p1 CMOS DCIA and a MC4F139 IC. I've gotton ahold of a number of R6522p nMOS chips, and I'm going to replace the CMOS R65C22p1 with it. The only difference I can see is the power disipation. The CMOS chip is rated at 7-10 mW/Mhz and the nMOS chip is rated at 450-700 mW. Does this make them incompatable? Also, I'm going to try and replace the MC74F139 with chips lables 74LS139. The difference being LS vs F. I think LS means low poew Shottsky, but what does F mean, and can I interchange the chips? Thanks for the info, Charles