Hello DOSEMU team, I could not find where to report bugs, so I hope this is a valid way. It seems that DOSEMU does not support newer CPU's. Maybe simply, because it was not updated since they arrived. I've checked the SVN version at http://dosemu.svn.sourceforge.net/viewvc/dosemu/trunk/src/base/init/ My /proc/cpuinfo says: vendor_id : AuthenticAMD cpu family : 16 model : 2 model name : AMD Phenom(tm) 9550 Quad-Core Processor The switch (get_proc_intvalue_by_key( kernel_version_code > 0x20100+74 ? "cpu family" : "cpu" )) { in src/base/init/config.c tests for values 5, 6, 586, 686, 15. The result is that config.cpu_spd is zero, which causes a "Division by zero" on booting dos. If you run dosemu with options -h0 -O it dumps the configuration to stderr. It dumps (among a lot else): CPUclock infMHz That is a (poorly formatted) "infinity" result of the division: (((double)LLF_US)/config.cpu_spd) in src/base/init/config.c Adding a case 16 to the switch statement solves this. It reports the CPU speed as 2210.17 MHz It also makes my DOSEMU boot. I'm not sure whether it's completely OK, yet. See the attached patch to the 1.4.0 version. There are more newer processors around. Here's number 17 in this Ubuntu bug report: https://lists.ubuntu.com/archives/universe-bugs/2009-January/036704.html Hans
151c151 < (*print)("CPUclock %gMHz\ncpu_spd 0x%lx\ncpu_tick_spd 0x%lx\n", --- > (*print)("CPUclock %g MHz\ncpu_spd 0x%lx\ncpu_tick_spd 0x%lx\n", 482a483,484 > case 16: > case 17: