Received: (from major@localhost) by minnie.cs.adfa.oz.au (8.8.5/8.8.5) id NAA02452 for pups-liszt; Wed, 15 Apr 1998 13:09:43 +1000 (EST) X-Authentication-Warning: minnie.cs.adfa.oz.au: major set sender to owner-pups@minnie.cs.adfa.oz.au using -f Received: from renoir.op.net (root@renoir.op.net [209.152.193.4]) by minnie.cs.adfa.oz.au (8.8.5/8.8.5) with ESMTP id NAA02444 for ; Wed, 15 Apr 1998 13:09:37 +1000 (EST) Received: from goppelt.op.net (d-phlarc1-00.ppp.op.net [209.152.199.64]) by renoir.op.net (o1/$Revision: 1.16 $) with SMTP id XAA00267 for ; Tue, 14 Apr 1998 23:09:25 -0400 (EDT) Message-Id: <199804150309.XAA00267@renoir.op.net> Comments: Authenticated sender is From: "Ed G." To: pups@minnie.cs.adfa.oz.au Date: Tue, 14 Apr 1998 23:09:26 -0400 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: PDP-11 Addressing Modes Reply-to: edgee@cyberpass.net X-mailer: Pegasus Mail for Win32 (v2.54) Sender: owner-pups@minnie.cs.adfa.oz.au Precedence: bulk The first line of chapter on addressing modes in the *processor handbook* states: "In the PDP-11 family, all operand addressing is accomplished through the eight general purpose registers." If I understand correctly, even things like immediate operands and addresses are represented as an addressing mode of a register, namely the PC. I think this is quite cool. What do people here on the list think of the flexibility and generality of the PDP-11's addressing modes? Is this a well thought out architecture in your view? How are the PDP-11's addressing modes better or worse than those of other processors, past and present?