I have been trying with no success to gather data from the various manufacturers of 72 pin JEDEC simm modules. I need an approximate figure for the characteristic impedance of the control traces, (CAS0-3 in particular). If anyone out there can help on this I would be most grateful. I can calculate it if anyone even knows the makeup of the blank PCB with track widths etc. TIA, -- --------------------------------- Steve Boorman [log in to unmask] --------------------------------- ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################