7/25/91 KC, The file qsim.in contains the command file which I use to run qsim. The command I use is as follows: vlsishell temp.log You might want to check this file to see if there is anything blatantly stupid. The hierarchical name of the modules which I'm having trouble with are u8.u1.u87$1 through u8.u1.u87$16, u8.u1.u98$1 through u8.u1.u98$8, and u8.u1.u99$1 through u8.u1.u99$8. Thanks for any help you can give. Doug Faust