From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, HTML_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 17036 invoked from network); 1 Sep 2021 18:44:01 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 1 Sep 2021 18:44:01 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id BD7249D55E; Thu, 2 Sep 2021 04:43:58 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 9FC5D9BA1D; Thu, 2 Sep 2021 04:43:25 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=ccil-org.20150623.gappssmtp.com header.i=@ccil-org.20150623.gappssmtp.com header.b="sWLNKXUV"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 213909BA1D; Thu, 2 Sep 2021 04:43:20 +1000 (AEST) Received: from mail-qv1-f45.google.com (mail-qv1-f45.google.com [209.85.219.45]) by minnie.tuhs.org (Postfix) with ESMTPS id A935E9B9F9 for ; Thu, 2 Sep 2021 04:43:18 +1000 (AEST) Received: by mail-qv1-f45.google.com with SMTP id eh1so366655qvb.11 for ; Wed, 01 Sep 2021 11:43:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ccil-org.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=m8VbQone7tLcsV4i/zkdjB+0q444i4FEiiQIWfYPFj4=; b=sWLNKXUVfNJPSD950f3L7gXLapLr414/aFwpxXp+0e3sJwwNkPYlfuO89ldbQ24VQ1 5UWAftGMoIj3uYfL1+sN5+MnKx6M4IvfwPRWMXYfOAl2fJtW/N9Ui7cWSS+Q6f/bqPPV RWTvzy0fhsSXQwHy5dIYbmbnFoar4niXfkRiRqqZpo4eMcAxsitOqBCfIRSJv0v01JVa MtZsPbBp/rlYt8yED2rfBE+IQTv3DaU2xPjHn/y/w+aUwNUG7mm1d2v8HVCi4d9FSENy qhD5STpl2N7FNytQXi4xBnLtgd0odQjLkJcaCB/YRPu/e9LzDb6MvUiM894sszAVZT+c wSdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=m8VbQone7tLcsV4i/zkdjB+0q444i4FEiiQIWfYPFj4=; b=HeBby2DrbQyi3BF+Qxeun/PhZKo5ZbzxEqxKUZ4rFUcBMe08AJO93RoTRe4UbztGzO PZvl91WMeQoLl1SyhWxHJVl7uy2Ul0Oxq4NaYEwmshkm7DZcH1J9uYQ+YKk2g05/kAUC O0LdIt2hs4xdoguIXINvYe62bPJBfk3rAmz2DEf/n/hmJQHLFNj1lmfz87o67oivpzOz 7NCWaLGLDwLwKXdIRtmZg0uLoIhpVcdAUl1N/O6KJW+w+tGrCLUT4Os0Jfjd/gIz8ZEC tRAYEK4F117WKQ3dDTXX5Nntc329jASN3Y3g49aGHlIYsi/uNFjzEpmtSxGGBkw2HF1j wwGA== X-Gm-Message-State: AOAM530OPkphFGzWusfaWi4wuO8RfwNeb8E2TYGd5rmIK23mwnNYlsGe h0b6I4qZiIKBmixhfCAkp5JG9pWaJOmisaa5Fc4H0OQ7sJyHX8/5 X-Google-Smtp-Source: ABdhPJwVjXJnsehC7kOuZVXD4hzcRI1AgtOqLQxlaTjAwyLDmjYV7JvvmGrHBlSCHmgvS9CrPZDrfU52QGQwUFxK5/k= X-Received: by 2002:a0c:d6cd:: with SMTP id l13mr1258844qvi.24.1630521797765; Wed, 01 Sep 2021 11:43:17 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: John Cowan Date: Wed, 1 Sep 2021 14:43:06 -0400 Message-ID: To: Ron Natalie Content-Type: multipart/alternative; boundary="0000000000008dfb0e05caf3702e" Subject: Re: [TUHS] A language question 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: TUHS main list Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --0000000000008dfb0e05caf3702e Content-Type: text/plain; charset="UTF-8" On Wed, Sep 1, 2021 at 12:07 PM Ron Natalie wrote: > I disagree. TRAP according to the processor handbook was intended to be > used for what UNIX calls system calls. EMT was the emulator trap used to > simulate other operating systems on the same hardware. > The 1969 PDP-11 Handbook < http://gordonbell.azurewebsites.net/digital/pdp%2011%20handbook%201969.pdf> says on p. 41 (PDF page 49): "[Trap] instructions provide for calls to emulators, I/O monitors, debugging packages, and user-defined interpreters", but it does not define "emulators". (The OED has several citations for this sense of "emulator", but before about 1985 the context seems to be hardware emulation only.) Nevertheless, DOS/BATCH-11 (1970-71) already uses EMT as the system call instruction, and it is clear that TRAP was for user use. At that point, the only other operating system that could be emulated would be the Paper Tape Software that I mentioned, which used IOT. (BTW, RSTS/E's hypervisor would reflect any EMT instruction to the RTS (the actual or emulated supervisor running in any given process, such as Basic-Plus, RT-11, RSX-11, or Teco), with the exception of an EMT 377, EMT 377 sequence, which was a syscall to the hypervisor itself.) --0000000000008dfb0e05caf3702e Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Wed, Sep 1, 20= 21 at 12:07 PM Ron Natalie <ron@ro= nnatalie.com> wrote:
=C2=A0
I disagree.=C2=A0 TRAP according to = the processor handbook was intended to be used for what UNIX calls system c= alls.=C2=A0 =C2=A0 EMT was the emulator trap used to simulate other operati= ng systems on the same hardware.

The 1969 PDP-11 Handbook <http://gord= onbell.azurewebsites.net/digital/pdp%2011%20handbook%201969.pdf> say= s on p. 41 (PDF page 49): "[Trap] instructions provide for calls to em= ulators, I/O monitors, debugging packages, and user-defined interpreters&qu= ot;, but it does not define "emulators".=C2=A0 (The OED has sever= al citations for this sense of "emulator", but before about 1985 = the context seems to be hardware emulation only.)

Nevertheless, DOS/BATCH-11 (1970-= 71) already uses EMT as the system call instruction, and it is clear that T= RAP was for user use.=C2=A0 At that point, the only other operating system = that could be emulated would be the Paper Tape Software that I mentioned, w= hich used IOT.

(BTW, RSTS/E's hypervisor would reflect any EMT instruction to t= he RTS (the actual or emulated supervisor running in any given process, suc= h as Basic-Plus, RT-11, RSX-11, or Teco), with the exception of an EMT 377,= EMT 377 sequence, which was a syscall to the hypervisor itself.)
--0000000000008dfb0e05caf3702e--