uname -a = xxx xxx 5.7 Generic_106541-12 sun4u sparc SUNW,Ultra-5_10 i'm core dumping on a sparc-solaris system while executing mySem.set_value(0,64) changing the call to mySem.set_all( [64] ) works fine as long as you are USING ONE SEMAPHORE. an otherwise fine interface to the more tricky than you think sysvipc c lib -ara ahoward / fsl.noaa.gov > see > http://www.ruby-lang.org/en/raa-list.rhtml?name=sysvipc > > Jakub Travnik > jabber://jtra / jabber.com