I ran your test on some machines here. DECsystem 5400, Ultrix 3.1C: VAX8600, 4.3 BSD: Your brk routine is broken! SparcServer: Sequent: MIPS: Your brk routine works correctly. -- -IAN! (Ian! D. Allen) idallen at watcgl.uwaterloo.ca idallen at watcgl.waterloo.edu [129.97.128.64] Computer Graphics Lab/University of Waterloo/Ontario/Canada