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=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 23250 invoked from network); 6 Mar 2023 08:52:25 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 6 Mar 2023 08:52:25 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 2FEAC41243; Mon, 6 Mar 2023 18:52:20 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tuhs.org; s=dkim; t=1678092740; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-owner:list-unsubscribe:list-subscribe:list-post; bh=pXIOto9s4eqIth/kQAr6I+DA1zesplTnVNMo4mbV3BU=; b=btouEt6WBsuf799z8V5bCyK5DkisI7wKrl6UNAAhrvsqfXZaNd07EUPZHp58Lc3kRHYYBR JuSEJlmW9B9tDOecLrkYdOm1+MANGBdr5agQU07DtAgwY7ap8ZHTOtNjrmhnB6mgkZciVM A3e/N2mPDpnZjyKzWBStx0112dgSAks= Received: from ewsoutbound.kpnmail.nl (unknown [195.121.94.170]) by minnie.tuhs.org (Postfix) with ESMTPS id C8A7241243 for ; Mon, 6 Mar 2023 18:52:03 +1000 (AEST) X-KPN-MessageId: 1a82bf27-bbfc-11ed-a286-005056ab378f Received: from smtp.kpnmail.nl (unknown [10.31.155.40]) by ewsoutbound.so.kpn.org (Halon) with ESMTPS id 1a82bf27-bbfc-11ed-a286-005056ab378f; Mon, 06 Mar 2023 09:51:36 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=planet.nl; s=planet01; h=message-id:to:date:subject:mime-version:content-type:from; bh=pXIOto9s4eqIth/kQAr6I+DA1zesplTnVNMo4mbV3BU=; b=eQVAcZteJSEKUlgJHQBd7cZtPH0K9cg6djSR8EZ+gow+Kb9zZ7Fwfe15hdnwzT2f1dVEcqy8oAAdu Et0hFYTBnwQUZFv2L2wKrhap2P3nUwM8KqqXMNRj5+P84hAFZ4crI8G0b5qVkJkPromCo442Fl8FmV /ZR8eOqQ8u0B/DRc= X-KPN-MID: 33|OE13YJxM/l71rZUJNkrDJe4BqmnJDj0XYKWUo2vdr9DO2xvxqkaVUH+w16hF4kR Y3IZVDFBLvkkV8cQd4aIpKm+0hgt8JqgqKtiYxQXh1BM= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|24eadtHw/VjGfF2sFJHXQjwkIghUf0P3A7Rn0aOo+b2qmCl11X/Ipwezk9bagIl zm2t2FG5xop0H3tzEFlACwQ== X-Originating-IP: 77.172.38.96 Received: from smtpclient.apple (77-172-38-96.fixed.kpn.net [77.172.38.96]) by smtp.kpnmail.nl (Halon) with ESMTPSA id 230e25ad-bbfc-11ed-927e-005056ab7584; Mon, 06 Mar 2023 09:51:51 +0100 (CET) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.120.0.1.13\)) Date: Mon, 6 Mar 2023 09:51:50 +0100 References: To: "tuhs@tuhs.org" In-Reply-To: Message-Id: <1297BE06-BE03-477A-AC60-40A269090295@planet.nl> X-Mailer: Apple Mail (2.3654.120.0.1.13) Message-ID-Hash: BXWEJOYAYLY63V7XJRG6W5HC65MZFWOB X-Message-ID-Hash: BXWEJOYAYLY63V7XJRG6W5HC65MZFWOB X-MailFrom: pnr@planet.nl 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 X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Origins of the frame buffer device List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: Paul Ruizendaal via TUHS Reply-To: Paul Ruizendaal Thanks for this. My question was unclear: I wasn't thinking of the hardware, but of the = software abstraction, i.e. the device files living in /dev I=E2=80=99ve now read through SunOS man pages and it would seem that the = /dev/fb file was indeed similar to /dev/fbdev on Linux 15 years later. = Not quite the same though, as initially it seems to have been tied to = the kernel part of the SunWindows software. My understanding of the = latter is still limited though. The later Linux usage is designed around = mmap() and I am not sure when that arrived in SunOS (the mmap call = exists in the manpages of 4.2BSD, but was not implemented at that time). = Maybe at the time of the Sun-1 and Sun-2 it worked differently. The frame buffer hardware is exposed differently in Plan9. Here there = are device files (initially /dev/bit/screen and /dev/bit/bitblt) but = these are not designed around mmap(), which does not exist on Plan9 by = design. It later develops into the /dev/draw/... files. However, my = understanding of graphics in Plan9 is also still limited. All in all, finding a conceptually clean but still performant way to = expose the frame buffer (and acceleration) hardware seems to have been a = hard problem. Arguably it still is. > On 5 Mar 2023, at 19:25, Kenneth Goodwin = wrote: >=20 > The first frame buffers from Evans and Sutherland were at University = of Utah, DOD SITES and NYIT CGL as I recall. >=20 > Circa 1974 to 1978. >=20 > They were 19 inch RETMA racks. > Took three to get decent RGB. >=20 > 8 bits per pixel per FB. >=20 > On Sun, Mar 5, 2023, 10:02 AM Paul Ruizendaal via TUHS = wrote: > I am confused on the history of the frame buffer device. >=20 > On Linux, it seems that /dev/fbdev originated in 1999 from work done = by Martin Schaller and Geert Uytterhoeven (and some input from Fabrice = Bellard?). >=20 > However, it would seem at first glance that early SunOS also had a = frame buffer device (/dev/cgoneX. /dev/bwoneX, etc.) which was similar = in nature (a character device that could be mmap=E2=80=99ed to give = access to the hardware frame buffer, and ioctl=E2=80=99s to probe and = configure the hardware). Is that correct, or were these entirely = different in nature? >=20 > Paul >=20