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=-0.8 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 549d05c1 for ; Wed, 18 Dec 2019 12:20:06 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id 2B95E9BC1B; Wed, 18 Dec 2019 22:20:05 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 2B4449BBF9; Wed, 18 Dec 2019 22:19:39 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (1024-bit key; unprotected) header.d=planet.nl header.i=@planet.nl header.b="chqVczWg"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 16B339BBF9; Wed, 18 Dec 2019 22:19:37 +1000 (AEST) Received: from cpsmtpb-ews02.kpnxchange.com (cpsmtpb-ews02.kpnxchange.com [213.75.39.5]) by minnie.tuhs.org (Postfix) with ESMTP id 416619B92E for ; Wed, 18 Dec 2019 22:19:35 +1000 (AEST) Received: from cpsps-ews26.kpnxchange.com ([10.94.84.192]) by cpsmtpb-ews02.kpnxchange.com with Microsoft SMTPSVC(7.5.7601.17514); Wed, 18 Dec 2019 13:19:33 +0100 X-Brand: 7abm2Q== X-KPN-SpamVerdict: e1=0;e2=0;e3=0;e4=(e1=10;e3=10;e2=11;e4=10);EVW:Whi te;BM:NotScanned;FinalVerdict:Clean X-CMAE-Analysis: v=2.3 cv=YbfDGDZf c=1 sm=1 tr=0 cx=a_idp_e a=ShNidqeCEQB33TAKUUzslw==:117 a=soxbC+bCkqwFbqeW/W/r+Q==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=x1i13A_MHe4A:10 a=IkcTkHD0fZMA:10 a=pxVhFHJ0LMsA:10 a=H6K-XWfdAAAA:8 a=m2ghwhEdAAAA:20 a=PQ_BvlDsAAAA:8 a=AoeSMSUmAAAA:8 a=cggplEk1AAAA:8 a=8zvtdvGnAAAA:8 a=RVFwQE6tAAAA:8 a=eeQHxzKcwiykWc5UUoQA:9 a=QEXdDO2ut3YA:10 a=--F_B-xtZd8A:10 a=I_eCv5egaXwI4U5zcS65:22 a=9N92cZ7GawaNicRbk1ai:22 a=2UY7SMgi64q-0UtCmZ5F:22 a=TyGOKPG1VZVQ-HZz1HdS:22 a=Q-xCa1abX5qBlSYUmlcr:22 a=Yj5hsy5CUz1hT_6v1iaJ:22 X-CM-AcctID: kpn@feedback.cloudmark.com Received: from smtp.kpnmail.nl ([195.121.84.11]) by cpsps-ews26.kpnxchange.com over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Wed, 18 Dec 2019 13:19:33 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=planet.nl; s=planet01; h=to:message-id:date:from:subject:mime-version:content-type; bh=ahy3vSJgkWeS+Wa3LZf6pl+Jz66VSYOjYUijgWJk1lY=; b=chqVczWgvJzuCUEim/5TK7yeee4tVWmmsU9l/RpxAQWQwl7sFcXRonPQaYB+3Y5FLLIiEpKD2eIsg rNLBwjBv+pApXvIYT9Q0osfOy0h1/Jx5scb1A278jPB0W2AWWV33lDwyzf1WfbuK/SpxZ2bu4YGP85 lNT9FtuW0zMc1tqk= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|USZ9ZiJlwh8uBi48n7gq47yC7MZyGN0pklRqJEfXjDkpRi3lm0rEYRXCjcHdNH2 vXvSACdePh8fxbSyCyoCczw== X-Originating-IP: 80.101.112.122 Received: from mba1.fritz.box (unknown [80.101.112.122]) by smtp.kpnmail.nl (Halon) with ESMTPSA id a62b7d37-2190-11ea-a62b-00505699b758; Wed, 18 Dec 2019 13:19:33 +0100 (CET) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) From: Paul Ruizendaal In-Reply-To: Date: Wed, 18 Dec 2019 13:19:33 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: References: <6be1d013-2323-9850-03fd-c4014c4a69e7@e-bbes.com> <766B1E87-501A-4675-91A5-DCDA35FFEB98@planet.nl> To: Julius Schmidt X-Mailer: Apple Mail (2.3445.9.1) X-OriginalArrivalTime: 18 Dec 2019 12:19:33.0988 (UTC) FILETIME=[6831BA40:01D5B59D] X-RcptDomain: minnie.tuhs.org Subject: Re: [TUHS] Blit source 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" The =E2=80=9Chardware / software tradeoffs=E2=80=9D paper I linked = yesterday has an interesting discussion about the mouse, including many = details of how it worked. It says that the Blit originally used a tablet = but was later redesigned to use a mouse. You may be seeing a few remains = of the the tablet interface. I noticed that the rom images are dated Dec 1982. The build process' = output file =E2=80=9Cromterm=E2=80=9D is dated Nov 1983. Some of the = libraries have source files with dates into 1984. It would seem that the = surviving rom images are for a fairly early iteration of the system. > On Dec 18, 2019, at 11:43 AM, Julius Schmidt wrote: >=20 > I also noticed that the ROM binaries differed from the source code, = when I was writing the Blit emulator, by comparing disassembled binaries = with the source. In particular, the compiled code makes reference to I/O = registers 025 and 027 that are not referenced in the source any more. (I = think there were some more differences I didn't bother to write down) >=20 > Julius Schmidt (aiju) >=20 > On Wed, 18 Dec 2019, Paul Ruizendaal wrote: >=20 >> Further to the below, I=E2=80=99ve now tried to build the Blit = toolchain (on a contemporary OS). Other than the usual little issues, it = does not take too much effort to get running. >>=20 >> Rebuilding the rom contents using the pre-existing libraries builds = the exact same bits, however here is also where the good stuff ends: = this only assembles two files, compiles vitty.c and the rest is library; = rebuilding the libraries is different. >>=20 >> The roms rely on four libaries (libsys, libj, liblayer and libc) and = none of the four rebuild to the exact same bytes or size. In several = cases the archives do not even have the exact same files in them. In = general, the regenerated object files often appear to be a little = smaller (even when compiled with optimization off). So far I cannot tell = whether this is because the compiler is different, or because the = underlying source code is different. Probably a bit of both. >>=20 >> So, it would seem that an adapted rom can be compiled, but how = functional it would be remains to be seen. >>=20 >> The note about the missing compiler remains intriguing. First a = correction: I associate =E2=80=9Cccom=E2=80=9D with the DMR compiler, as = it lives in a directory by that name; I had not realized that pcc also = names its main binary ccom. Beyond that it would seem that two different = versions of this 68K compiler were floating around and maybe the = surviving one puts different debug info in the symbol table. >>=20 >>=20 >>=20 >>>> Date: Sun, 15 Dec 2019 22:17:53 +0100 >>>> From: Angelo Papenhoff >>>>=20 >>>> On 15/12/19, Paul Ruizendaal wrote: >>>>> I=E2=80=99m aware of this emulator: >>>>> https://github.com/aap/blit >>>>=20 >>>> This is only a port to unix I did. The original one was written by = aiju. >>>> The upstream version (which is in fact more up to date) is part of = the 9front repo: >>>> = https://code.9front.org/hg/plan9front/file/5003ea45cc4d/sys/src/games/blit= >>>> Aiju reverse engineered the hardware from the source code on the = second tape: >>>> = https://www.tuhs.org/Archive/Distributions/Research/Dan_Cross_v8/v8jerq.ta= r.bz2 >>>=20 >>> Thanks! The =E2=80=9Cblit=E2=80=9D directory in that archive indeed = appears to be what I=E2=80=99m looking for. Hopefully it has enough to = enable rebuilding from source. >>>>=20 >>>> I don't know how complete it is and I think the compiler is also = not >>>> included, but I'm not too sure how it all worked. >>>=20 >>> =46rom a quick inspection there appears to be a subdirectory =E2=80=9C= m=E2=80=9D with motorola tools. It appears to have a M68K pcc-based = compiler. It also has this README file: >>>=20 >>> =3D=3D=3D >>> the source for /usr/blit/lib/ccom has been lost. >>> the source here (Mip and Mcc) is for a compiler that does not = generate >>> the correct symbol tables for joff and pi. >>> we wish we had the source, but we don't, so the binary is precious. >>> please handle it with care. >>>=20 >>> if you decide you need to recompile ccom, contact us. >>> we may have found a solution by then... >>> =3D=3D=3D >>>=20 >>> The =E2=80=9Cbin=E2=80=9D directory has that ccom binary. It = suggests that there once was a M68K compiler that derived from the = Ritchie PDP11 compiler. I assume that the source for that has stayed = missing ever since 1985. >>>=20 >>>> On 16 Dec 2019, at 07:25, emanuel stiebler wrote: >>>>=20 >>>> On 2019-12-15 21:45, Paul Ruizendaal wrote: >>>>> I=E2=80=99m looking for source code of the original Blit as = described here: >>>>> http://doc.cat-v.org/bell_labs/blit/blit.pdf >>>>=20 >>>> Thanks for trying again. It pops up on this list every few years, = but >>>> still no schematics (2002, 2012) =E2=80=A6 >>>=20 >>> It would seem that the circuit was intentionally simple and = straightforward: a M68K cpu, ram, rom, two 6850 UARTS and the circuit to = drive the display. The key aspects of the video circuitry (and mouse = circuitry) are discussed in this paper: >>> https://9p.io/cm/cs/doc/87/archtr.ps.gz ("Hardware/Software = Tradeoffs for Bitmap Graphics on the Blit=E2=80=9D). >>>=20 >>> It would seem to me that doing a version of the Blit that runs on a = FPGA board and generates 720p HDMI output would not be impossible to do, = if the software can be configured to deal with a different geometry = (e.g. 1024x720 instead of 800x1024). Whether that would be much = different from running the emulator on a PC remains unclear, of course. >>=20 >>=20 >>=20 >>=20