From: utzoo!decvax!cca!fred.umcp-cs@Udel-Relay@sri-unix Newsgroups: net.unix-wizards Title: compat (v7run) Article-I.D.: sri-unix.3253 Posted: Mon Sep 13 14:36:07 1982 Received: Tue Sep 14 05:23:00 1982 From: Fred BlonderDate: 9 Sep 82 18:25:32-EDT (Thu) From: Charles F. Von Rospach Does anyone have any documenation on 'compat'? All I can find out about it is that it emulates PDP11 V7 Unix so you can run Zork. Is this correct? Is it robust enough to handle something like a CBASIC interpreter for PDP11, or are we in for trouble? Where can I get detailed info on compat? In our experience ``compat'' is pretty reliable, but there's a minor bug in it: It places TWO null pointers on the stack after the arguments instead of one. This means that when the PDP-11 program looks for the pointer to the first environment variable, it sees the second null pointer, and can't find the environment at all, even though it's really there on the stack, offset by one. The fix is to delete line 76 from unixstart.c 76d76 < *(--ssp) = 0; --- as distributed with 4.1BSD.