From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id 6f7eac20 for ; Thu, 30 Jan 2020 06:41:43 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 1E0AA9CB1C; Thu, 30 Jan 2020 16:41:42 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 7CDB19CB07; Thu, 30 Jan 2020 16:41:16 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=papnet.eu header.i=@papnet.eu header.b="QQE5bSzT"; dkim=pass (2048-bit key; unprotected) header.d=messagingengine.com header.i=@messagingengine.com header.b="dml8EJ45"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id ED5309CB07; Thu, 30 Jan 2020 16:41:11 +1000 (AEST) X-Greylist: delayed 540 seconds by postgrey-1.36 at minnie.tuhs.org; Thu, 30 Jan 2020 16:41:10 AEST Received: from out3-smtp.messagingengine.com (out3-smtp.messagingengine.com [66.111.4.27]) by minnie.tuhs.org (Postfix) with ESMTPS id 3ACFB9CB06 for ; Thu, 30 Jan 2020 16:41:10 +1000 (AEST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 956D021B2A; Thu, 30 Jan 2020 01:32:09 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Thu, 30 Jan 2020 01:32:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=papnet.eu; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm3; bh=Cv4mLCa1Q5kEZmOFG4Ly7ujaXkU IWtkU5lT8PJsk2k8=; b=QQE5bSzTgfpwLAmB1rwux5R6D1QoPuhxhaBBO1g1zFo xWgDU/3um9Mg/+LdGuFGljDXA62DjBouU/WLecWHFBPWOvHZGUcaCnq4X53IMQsG br9TSAG7Ey8+wvPctzrvE5UySbqZnGpz+77/KXVLUfr8Qw8XOs09657tr5D48IMs KdwnPMk34pYLxs7Y4z/AUJ9u53rDb0FVlYjU/lCvTeSVK0x/eXRtiXZfR+qkprcR gFLQfDH5MQK6zNy3YQWlp0E2dUu5JZThVhIB0cEPqZLEIQHgUOeP/su5fOU5L7ys W7otx+txB01s8w8WHFXC2Gm82+hk1UlyJ3G2tUsNXPA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=Cv4mLC a1Q5kEZmOFG4Ly7ujaXkUIWtkU5lT8PJsk2k8=; b=dml8EJ45KY0j7JfUdRkGGb bKfC05WGTKHHDWwiSU1xZJxw58FnADwtIpJUSHauTtaXs/n7o/whZ4Jq+jl2miQ8 jwkCCpFyxmp0Nf/R7V5OLxKRIGRZ7tk6lSVeMdzGF1ECWzpgfum5q06sCNsF9McF xRMhzsE+8h+1AuX3nGxVksLSTLJ8Uy64pGwzPjxCPiXd7TBgbK12PkknGyVTwwIi TfiSUFrBjxsPE7bvKNK4dohoBHOCL1MwBOL+4NX3Xz1DI6XXr1SAmyMk1RRzT3Fh COTnzNDGwTBnRDQQUbmSkWWdqnWPzXLNakxrwKPU/e25bxVAW+YBkcq4cPVxYjaw == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrfeejgdelfecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpeffhffvuffkfhggtggujggfsehttdertddtredvnecuhfhrohhmpeetnhhgvghl ohcurfgrphgvnhhhohhffhcuoegrrghpsehprghpnhgvthdrvghuqeenucfkphepjeekrd ehhedruddugedrgeefnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghi lhhfrhhomheprggrphesphgrphhnvghtrdgvuh X-ME-Proxy: Received: from indra.papnet.eu (x4e37722b.dyn.telefonica.de [78.55.114.43]) by mail.messagingengine.com (Postfix) with ESMTPA id B13C8328005A; Thu, 30 Jan 2020 01:32:08 -0500 (EST) Date: Thu, 30 Jan 2020 07:32:06 +0100 From: Angelo Papenhoff To: Dave Horsfall Message-ID: <20200130063206.GA28074@indra.papnet.eu> References: <20200122184244.14CBB18C083@mercury.lcs.mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.0 (2016-04-01) Subject: Re: [TUHS] Unix quix X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: The Eunuchs Hysterical Society Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" On 30/01/20, Dave Horsfall wrote: > On Wed, 22 Jan 2020, Noel Chiappa wrote: > > [ Whirlwind ] > > > Pretty interesting machine, if you study its instruction set, BTW; with > > no stack, subroutines are 'interesting'. > > Not much worse than the PDP-8 :-) Plant return address in first word and > jump to the second word; to return, do an indirect jump to the first word. > > Recursion was possible. but I think you had to emulate the stack. On the whirlwind the sp (subprogram) instruction puts the return address in the A register. with ta (transfer A) you can put it into the address part of an instruction, so a function call is as simple as ... sp foo ... foo: ta foo0 ... foo0: sp . So it's pretty nice you can use sp for calls and jumps. cp (conditional sp) works the same but only jumps if AC is negative. The big difference between the WW and later machines is that there is no indirection on the WW! You end up writing lots of addresses into instructions. It's even weirder on the TX-0 with its (original) limited instruction set where you don't even have instructions to just store an address, only the full word. aap