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Re: [Oberon] Reconciling branches in the git repository.
by Michael Schierl 24 Jun '24

24 Jun '24

Hello, Am 16.06.2024 um 20:36 schrieb peter(a)easthope.ca: > Currently the A2 repository has branches main, bohdan and override. > > main seems a reasonable choice for me. Therefore, to update the local > copy of the repository, did this, > root@imager:/home/root/A2# git pull origin main > with this result. > > hint: Pulling without specifying how to reconcile divergent branches is > hint: discouraged. You can squelch this message by running one of the following > hint: commands sometime before your next pull: > hint: > hint: git config pull.rebase false # merge (the default strategy) > hint: git config pull.rebase true # rebase > hint: git config pull.ff only # fast-forward only > hint: > hint: You can replace "git config" with "git config --global" to set a default > hint: preference for all repositories. You can also pass --rebase, --no-rebase, > hint: or --ff-only on the command line to override the configured default per > hint: invocation. > > If a specific branch is pulled, why is reconciliation necessary? "git pull" will pull changes from a branch and integrate them to your current working copy. If your working copy currently is not at a state that is a previous state of the branch you are pulling (e.g. has local modifications, or was on a different branch altogether), this may result in a merge or rebase. If you do not want that, you can choose the third option. If, on the other hand, your working copy is at a previous state of the working copy you are pulling, the option does not matter and git will always perform a fast forward. In case you want to just switch your working copy to match a branch (discarding the your current working copy commit), you can use "git checkout" instead. "SVN update" is similar to "git pull" with using rebase strategy (second option). Which is (if I recall correctly) the reason why they added this hint message, as git's default action is the first one and it confused people with a SVN background. Regards, Michael

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Reconciling branches in the git repository.
by peter＠easthope.ca 16 Jun '24

16 Jun '24

Currently the A2 repository has branches main, bohdan and override. main seems a reasonable choice for me. Therefore, to update the local copy of the repository, did this, root@imager:/home/root/A2# git pull origin main with this result. hint: Pulling without specifying how to reconcile divergent branches is hint: discouraged. You can squelch this message by running one of the following hint: commands sometime before your next pull: hint: hint: git config pull.rebase false # merge (the default strategy) hint: git config pull.rebase true # rebase hint: git config pull.ff only # fast-forward only hint: hint: You can replace "git config" with "git config --global" to set a default hint: preference for all repositories. You can also pass --rebase, --no-rebase, hint: or --ff-only on the command line to override the configured default per hint: invocation. If a specific branch is pulled, why is reconciliation necessary? Thanks, ... P.L. -- VoIP: +1 604 670 0140 work: https://en.wikibooks.org/wiki/User:PeterEasthope

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An alternative for the present inaccurate Math.ln(x)
by Hans Klaver 03 Jun '24

03 Jun '24

Hi all, Did anyone notice that the Project Oberon 2013 Math.ln(x) function gives very sloppy results, only the first decimal or first few decimals being correct? While trying to produce a fractal on letter H (a nice programming task when your name is Hans ;-) and getting the result in figure 1, I first blamed my home grown graphics routines, but it soon became clear that Math.ln was the culprit. I use that function in my implementation of Math.power() which I need to calculate a contraction factor for the fractal. To see the inaccuracy just calculate ln(5.0) with a calculator or on www.wolframalpha.com and compare it with the result of Math.ln(5.0): the correct result to 6 decimal places should be 1.609438E+00 but Math.ln gives 1.621313E+00. First I hoped that a typo was the cause: in the PO book (Applications, p. 83) constant q1 = 6.176106560E1, whereas in the source q1 = 6.76106560E1. But changing that value gave little improvement. With the help of two older Oberon implementations I was able to figure out a correct version of Math.ln(x) which also uses the UNPK(x, e) standard procedure, and doesn't need to import SYSTEM. The new correct version turns out to be even simpler than the present one. PROCEDURE ln* (x: REAL): REAL; (* hk 18 May 2024 *) CONST c1 = 0.70710678; (* 1/ sqrt(2) *) c2 = 0.69314718; (* ln(2) *) c3 = 0.89554059; c4 = 1.82984424; c5 = 1.65677798; VAR e: INTEGER; y: REAL; BEGIN ASSERT(x > 0.0); UNPK(x, e); y := x * 0.5; INC(e); IF y < c1 THEN y := 2.0*y; DEC(e) END; y := (y-1.0)/(y+1.0); y := c2*FLT(e) + y*(c3 + c4/(c5 - y*y)) RETURN y END ln; PROCEDURE ln*(x: REAL): REAL; (* INCORRECT version *) CONST c1 = 0.70710680; (* 1/sqrt(2) *) c2 = 0.69314720; (* ln(2) *) p0 = -9.01746917E1; p1 = 9.34639006E1; p2 = -1.83278704E1; q0 = -4.50873458E1; q1 = 6.76106560E1; q2 = -2.07334879E1; VAR e: INTEGER; xx, y: REAL; BEGIN ASSERT(x > 0.0); UNPK(x, e); IF x < c1 THEN x := x*2.0; e := e-1 END ; x := (x-1.0)/(x+1.0); xx := x; y := c2*FLT(e) + x*((p2*xx + p1)*xx + p0) / (((xx + q2)*xx + q1)*xx + q0); RETURN y END ln; The two older versions (one from 1995 by Michael Griebling and another by an unknown author from the 1999 ETH Oberon System 3 release 2.3) give the exact same correct results, but could not use UNPK and therefore are much more and somewhat more convoluted. The procedures UNPK and PACK prove very useful to implement these mathematical functions. In Griebling's version the functionality of UNPK is given by two functions fraction() and exponent() and that of PACK by a function scale(); they need SYSTEM.VAL() and SET. Also in the 1999 ETH version SYSTEM.VAL() and SET is used. You can find them on my GitHub pages, along with a TestMath module. (https://github.com/hansklav/Oberon-07-Math.ln/tree/main) There you can also find the (imho) missing arctan() function. (https://github.com/hansklav/Oberon-07) As far as I could test them the other functions in module Math (sqrt, exp, sin, cos, arctan) are accurate enough. For those who are puzzled by procedures UNPK and PACK it may be informative to know that in most other languages their functionality is given by functions named frexp() and ldexp() or scalbn(). These routines are used to extract the binary fraction and exponent of 2 from a floating-point value, and to synthesize a float from these components. They provide a way to get at the internal representation of a float without doing direct bit manipulation. Wirth only used them in module Math. With the new Math.ln() function the H fractal looks much prettier ;-) Regards, Hans Klaver

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Re: [Oberon] Re (2): [EXT] Re: Univ. Linz Oberon collection
by Ruben Schuller 21 May '24

21 May '24

Hi Peter, 2024-05-21 peter(a)easthope.ca: > > ... would really be a shame if the work that has been done is lost. > > > > Exactly my thinking years ago and it motivated me to start the > wikibook. I don't have very much spare time to explore Oberon, but the wikibook is a great resource. > > License permitting, things should be archived at archive.org or > > maybe on wikimedia, as the book is also hosted there. > > A source as HTML is readily available to a novice. Wiki editing > allows correction of a bug. Indeed! I was thinking of the software, things linked to in the book. Most is found on Sourceforge or GitHub, so it's not a pressing matter. I do wonder how many things are living on FTP servers (or something alike) though. > I regret not having more time for the wikibook. I'm grateful that people work on things like you do on the wikibook at all! :) Kind Regards Ruben

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Re (2): [EXT] Re: Univ. Linz Oberon collection
by peter＠easthope.ca 21 May '24

21 May '24

Hello Ruben, From: Ruben Schuller <mail(a)rbn.im> Date: Tue, 21 May 2024 22:55:35 +0200 > ... would really be a shame if the work that has been done is lost. Exactly my thinking years ago and it motivated me to start the wikibook. > License permitting, things should be archived at archive.org or > maybe on wikimedia, as the book is also hosted there. A source as HTML is readily available to a novice. Wiki editing allows correction of a bug. I regret not having more time for the wikibook. Regards, ... P. -- VoIP: +1 604 670 0140 work: https://en.wikibooks.org/wiki/User:PeterEasthope

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[EXT] Re: Univ. Linz Oberon collection
by Andreas Pirklbauer 21 May '24

21 May '24

> There is always email address behind particular source code. > > For example moessenboeck at ssw.uni-linz.ac.at > > Did you ask for confirmation oberon programming is really dead at jku? The University of Linz has stopped using Oberon as a primary teaching languages years ago and has switched to other languages. In particular Java, where they did some work in collaboration with Sun Microsystems, now Oracle. And since Prof. Mössenböck is about to retire, someone else would need to bring Oberon back to live in Linz.. which appears a bit unlikely. It’s similar to ETH Zurichm where most people who have carried Oberon forward throughout the years have retired or are retiring soon.

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Re: [Oberon] Grammar & language convention.
by Hans Klaver 21 May '24

21 May '24

Hi Peter, I think in German one would say: 'studieren an der ETH Zürich', but I suppose even a German speaking person would say in English (both British and North American E.) 'Studying at ETHZ'. > peter(a)easthope.ca wrote: > > Hi, > > https://en.wikibooks.org/wiki/Oberon/Introduction#Educational_Workstation > has this sentence. > Oberon is used as a workstation OS in the course in System Construction at the ETHZ. > > In North American English the article would be omitted. > Oberon is used as a workstation OS in the course in System Construction at ETHZ. > > A question of grammar may be involved but I'm not a grammarian. Which > form is preferable in Zurich? > > Thanks, ... P. > > > > > > -- > VoIP: +1 604 670 0140 > work: https://en.wikibooks.org/wiki/User:PeterEasthope > > -- > Oberon(a)lists.inf.ethz.ch mailing list for ETH Oberon and related systems > https://lists.inf.ethz.ch/mailman/listinfo/oberon

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Re: [Oberon] Univ. Linz Oberon collection
by peter＠easthope.ca 10 May '24

10 May '24

Wojtek, From: "Skulski, Wojciech" <skulski(a)pas.rochester.edu> Date: Fri, 10 May 2024 03:25:23 +0000 > I suggest that everyone grabs the file and stores in some safe > place. Thanks for your message. Unfortunate that someone at Linz hasn't put V4 in a Git archive. The world has a big population. Might still happen. Ideally https://en.wikibooks.org/wiki/Oberon/Linz_Oberon,_V4 would be developed fully, including all sources. At present I simply don't have the required time. =8~( Also regret that I can't focus at putting an Oberon on one of your Risc machines. A network connection requires security and A2 is the only Oberon with TLS. Security is required in V5. Thanks! ... P. -- VoIP: +1 604 670 0140 work: https://en.wikibooks.org/wiki/User:PeterEasthope

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Grammar & language convention.
by peter＠easthope.ca 09 May '24

09 May '24

Hi, https://en.wikibooks.org/wiki/Oberon/Introduction#Educational_Workstation has this sentence. Oberon is used as a workstation OS in the course in System Construction at the ETHZ. In North American English the article would be omitted. Oberon is used as a workstation OS in the course in System Construction at ETHZ. A question of grammar may be involved but I'm not a grammarian. Which form is preferable in Zurich? Thanks, ... P. -- VoIP: +1 604 670 0140 work: https://en.wikibooks.org/wiki/User:PeterEasthope

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Re: [Oberon] Oberon Digest, Vol 238, Issue 6
by Daniel Schmid 06 May '24

06 May '24

Dear Elen Honestly speaking i don't understand what exactly you'r going to emulate and so if this information will help, but anyway let me say; i got an Evaluation Board from Digilent with an Artix-7 FPGA on it and then could - with the support of astrobe - program the NW RISC5 processor from the Verilog source. Oberon is running well on it. So this is no original but current hardware. Best regards from Switzerland Daniel On Sun, 2024-03-17 at 12:00 +0100, oberon-request(a)lists.inf.ethz.ch wrote: > Send Oberon mailing list submissions to > oberon(a)lists.inf.ethz.ch > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.inf.ethz.ch/mailman/listinfo/oberon > or, via email, send a message with subject or body 'help' to > oberon-request(a)lists.inf.ethz.ch > > You can reach the person managing the list at > oberon-owner(a)lists.inf.ethz.ch > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Oberon digest..." > > > Today's Topics: > > 1. Emulating Project Oberon's RISC5 Architecture using Icarus > Verilog (Elen Edain) > 2. Re: Emulating Project Oberon's RISC5 Architecture using > Icarus Verilog (Hellwig Geisse) > > > --------------------------------------------------------------------- > - > > Message: 1 > Date: Sat, 16 Mar 2024 10:15:05 +0000 > From: Elen Edain <elen.edain(a)protonmail.com> > To: oberon(a)lists.inf.ethz.ch > Subject: [Oberon] Emulating Project Oberon's RISC5 Architecture using > Icarus Verilog > Message-ID: > <jQ3PCiO9X0FdAiKZeNURSPbsnrvCMK4suFF9FnBwOsH5JKsA4_UGIumFYdAD > tMQ_AoBMO0PNVjKpb41k1n1v0yO8S1uOyBUQX62krC5ve5Q=(a)protonmail.com> > > Content-Type: text/plain; charset="utf-8" > > Hello and Greetings from Iceland, > > I am currently undertaking a project to simulate the Project Oberon > RISC5 system architecture using Icarus Verilog, aiming to replicate > the system?s environment in a manner similar to QEMU for educational > exploration. This endeavor is inspired by Niklaus Wirth's educational > vision, focusing on understanding system design comprehensively. > > Despite progress, I've encountered a challenge with emulating > specific FPGA modules (originally on a Digilent Spartan 3 board), > notably the DCM, RAM16X1D, and IOBUF modules, as a software > simulation. This aspect falls beyond my expertise as a software > engineer, primarily dealing with hardware emulation nuances. Thus I > am on a learning journey as well and it is early days. > > I am seeking the community's expertise and advice on simulating these > FPGA modules in Verilog, to further develop a detailed tutorial > aligned with Wirth's original documentation, thereby eliminating the > dependency on the original FPGA board. > > The ultimate aim is to produce a contemporary, step-by-step guide for > working through the Project Oberon ecosystem without the need for the > original FPGA board. Any advice, resources, or guidance on where to > start with these hardware component emulations would be greatly > appreciated. > > Best regards, > > Elen >

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