Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!security!genrad!decvax!harpo!seismo!hao!hplabs!sri-unix!hartwell@shasta From: hartwell%shasta@sri-unix.UUCP Newsgroups: net.unix-wizards Subject: Re: Putting two memory controllers on a 780? Message-ID: <13210@sri-arpa.UUCP> Date: Tue, 1-Nov-83 17:25:00 EST Article-I.D.: sri-arpa.13210 Posted: Tue Nov 1 17:25:00 1983 Date-Received: Sun, 6-Nov-83 09:58:16 EST Lines: 18 From: Steve Hartwell One advantage to having 2 memory controllers is that you can interleave memory, such that the 1st quadword comes from memory off of the 1st controller, the 2nd quadword comes from memory off of the 2nd controller, etc. This balances the controller load, though it is difficult [for me, anyway] to estimate the performance improvement in a paged environment, though I suspect that it is worth it in most cases. In order to interleave, you MUST have equal amounts of memory on both controllers; in your case, 3.25Mb off each controller. You must also diddle the controller registers just before loading unix off of the floppy, or autoconfig() will not "see" the 2nd bank of memory. This is done very easily by adding 2 DEPOSIT commands in the DEFBOO.CMD file on the boot floppy. I can send the magic numbers to anyone who would like to have them. Steve Hartwell, Stanford University