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=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HTML_MESSAGE,MAILING_LIST_MULTI,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 29671 invoked from network); 18 Dec 2023 17:19:02 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 18 Dec 2023 17:19:02 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 6325643DD5; Mon, 18 Dec 2023 05:00:09 +1000 (AEST) Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) by minnie.tuhs.org (Postfix) with ESMTPS id 55B8E43DD4 for ; Mon, 18 Dec 2023 05:00:05 +1000 (AEST) Received: by mail-ej1-x62e.google.com with SMTP id a640c23a62f3a-a2339939573so78893766b.3 for ; Sun, 17 Dec 2023 11:00:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20230601.gappssmtp.com; s=20230601; t=1702839604; x=1703444404; darn=tuhs.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=tZeIgcNt9eX3iDn4KjMY13oc2qHFxgZVMQ4/uTlvNzw=; b=NpcXPI6Ss4uZ40POaGJw0ICJkY/Pfpnn9xYabu9ddKvIQUf3+qtdafttSx8qycKRhN Gl4/IswI5PJHh0WRVUy0+mcYQ2Zqcd7Za9/Rcs/UqN0vMoOupagQep53tepL0OHlzqWu UmMXYLcQNMylZD3ZVL8eRiGPuIMtCPhcTr5yEsm8rvQ/Gn1jMRQFByPYYBbNjzH2BgTZ k2NQjNtNvVIPmd9XjWfxXw02qmMBiZJFYJS63H2uOvS7FPzWB7xv79FaPjaC85cyrdxO GVQMkSCWOguc5iFJuSu6T4xD77f5G7fFxN6l+uPuBhbnRMphQlAZg9s1veaoUEjphNIB qf8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702839604; x=1703444404; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=tZeIgcNt9eX3iDn4KjMY13oc2qHFxgZVMQ4/uTlvNzw=; b=tSdoN7JERV1jDyCXC5y0siws4+s1G+zG9pvAYwMRmCiiK/wifyGOkTPKXhpupHmNpk psB+ZkFjHnYI2UUziSQCt2r/V3wPhS1OXLTpVDm5byVpNW2XkWMIgtnTCkcYeyYfOikH gvJHVqqqsRS+MtQi5X6+v3F4t8c4D5uq21WOAxyMdAH70nhBPqe33u0sAmz0bajf13wC TO6n/YHWHmXUeIy5pgL8Hn7qRab4IfzFNqh2IraMv8ZlOnvKUDFXX2/olXJ8iPT9RxLD y5DwuvVc/Gb3hjX634GZCCffg909LNqxDFDIVYzyMcvpWWVg45jSLbqqbXLKNr1bSZyj b5mw== X-Gm-Message-State: AOJu0Yy/JtIcySPEBpPBGWK+QQdElIF9tk29S28IfgBrlAw1pQgcSHAo pTKwaGQQuHhX7Lzh+JVPRaWLbZkrX7AVqhAF8AnE2hWdcK0/s6EfZzU= X-Google-Smtp-Source: AGHT+IF3OzxuUu6KH0eS6wWSYFidHtVey0oTT6RYria7YTUw7YcvN1MUiR+t1K0EGlKT7f4Snkb6Y4WRB9JUSoEe028= X-Received: by 2002:a17:906:30ca:b0:a02:9c3d:6de7 with SMTP id b10-20020a17090630ca00b00a029c3d6de7mr7577974ejb.13.1702839603438; Sun, 17 Dec 2023 11:00:03 -0800 (PST) MIME-Version: 1.0 References: <7AD36632-2B2F-43E2-999D-4F6373C3C64C@pobox.com> <17d9946c-6f41-4c56-9cb0-3218a2550299@ucsb.edu> In-Reply-To: From: Warner Losh Date: Sun, 17 Dec 2023 11:59:52 -0700 Message-ID: To: Paul Winalski Content-Type: multipart/alternative; boundary="000000000000ac39a6060cb93d72" Message-ID-Hash: 56Z6KCU74CE6YBEB2CWNVBDGVXSVTT5W X-Message-ID-Hash: 56Z6KCU74CE6YBEB2CWNVBDGVXSVTT5W X-MailFrom: wlosh@bsdimp.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: tuhs@tuhs.org X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Compatibility question List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --000000000000ac39a6060cb93d72 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, Dec 17, 2023 at 11:48=E2=80=AFAM Paul Winalski wrote: > One problem that the VT100 emulators may have is that they behave > according to the published VT100 specifications rather than the actual > hardware behavior. > They behave like the author of the emulator thinks the documentation describes. But often, ambiguity in descriptions lead to bad decisions here, especially when you go to the far right of the screen, the bottom right corner, etc. There's several quirks of VT100 behavior that just aren't clearly documented. They aren't bugs, per se, but people depend on that behavior. > The VT100 had notoriously buggy firmware. Alan Kotok, one of DEC's > early engineers, encountered some of these and was annoyed enough > about it that he wrote a program to generate a complete list of escape > sequences--legal and illegal--which he fed to his VT100 terminal. The > results were highly entertaining. Some perfectly valid escape > sequences were mishandled by the firmware and had behavior that didn't > match the documentation. Even worse, some illegal escape sequences > caused catastrophic behavior, such as the terminal freezing with the > alarm continuously on--the only way out was to power-cycle the > terminal. One particularly nasty escape sequence caused corruption of > the EPROM such that the terminal crashed on power-up or restart, > resulting in an infinite crash-and-restart loop that could only be > fixed by sending the terminal in for a factory reset. > > Kotok published his results within DEC engineering and shortly > thereafter "email bombs" containing escape sequences that triggered > some of the milder of the bugs started circulating. The VAX/VMS mail > utility had to be changed to filter out escape sequences by default. > Yea... Those are fun... I wonder how many got fixed in later versions? I'd also read somewhere that VT220 development was slowed by having to behave exactly the same way as the VT100s (the above example was one given)... But at least they had the benefit of being able to look at the old firmware code... At least I'd suppose that was a benefit... Warner --000000000000ac39a6060cb93d72 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


=
On Sun, Dec 17, 2023 at 11:48=E2=80= =AFAM Paul Winalski <paul.win= alski@gmail.com> wrote:
One problem that the VT100 emulators may have is that they b= ehave
according to the published VT100 specifications rather than the actual
hardware behavior.

They behave like the= author of the emulator thinks the documentation describes.
But o= ften, ambiguity in descriptions lead to bad decisions here, especially=C2= =A0when
you go to the far right of the screen, the bottom right c= orner, etc. There's several
quirks of VT100 behavior that jus= t aren't clearly documented. They aren't bugs,
per se, bu= t people depend on that behavior.
=C2=A0
The VT100 had notoriously buggy firmware.=C2=A0 Alan Kotok, one of DEC'= s
early engineers, encountered some of these and was annoyed enough
about it that he wrote a program to generate a complete list of escape
sequences--legal and illegal--which he fed to his VT100 terminal.=C2=A0 The=
results were highly entertaining.=C2=A0 Some perfectly valid escape
sequences were mishandled by the firmware and had behavior that didn't<= br> match the documentation.=C2=A0 Even worse, some illegal escape sequences caused catastrophic behavior, such as the terminal freezing with the
alarm continuously on--the only way out was to power-cycle the
terminal.=C2=A0 One particularly nasty escape sequence caused corruption of=
the EPROM such that the terminal crashed on power-up or restart,
resulting in an infinite crash-and-restart loop that could only be
fixed by sending the terminal in for a factory reset.

Kotok published his results within DEC engineering and shortly
thereafter "email bombs" containing escape sequences that trigger= ed
some of the milder of the bugs started circulating.=C2=A0 The VAX/VMS mail<= br> utility had to be changed to filter out escape sequences by default.

Yea... Those are fun...=C2=A0 I wonder how ma= ny got fixed in later versions?

I'd also read = somewhere that VT220 development was slowed by
having to behave e= xactly the same way as the VT100s (the above
example was one give= n)...=C2=A0 But at least they had the benefit of being
able to lo= ok at the old firmware code... At least I'd suppose that was
= a benefit...

Warner=C2=A0
--000000000000ac39a6060cb93d72--