- Oberon - mailman3.inf.ethz.ch

Impartial observation? (Or silly blather from left field?); was: ALU 2015 and 2018.
by peter＠easthope.ca 14 May '22

14 May '22

In first year computer science, two rules were easily prosecuted by a teaching assistant. (1) Use meaningful names. Eg. upperLimit means more than y. (2) Avoid magic numbers. Eg. AperyConstant is preferable to 1.2020569. From: "Skulski, Wojciech" <skulski(a)pas.rochester.edu> Date: Thu, 12 May 2022 20:29:00 +0000 > ... 1... Violates (2)? And "One = 1" would violate (1). Of course, someone with an established comprehensive understanding sees a non-issue. The entire stanza containing 1 is understood immediately. It's the person lacking comprehensive understanding who has difficulty. TTFN, ... P.L. -- mobile: +1 778 951 5147 VoIP: +1 604 670 0140 48.7693 N 123.3053 W

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ALU 2015 and 2018
by Andreas Pirklbauer 13 May '22

13 May '22

fd > > Writing correct code is already demanding enough, but writing publishable (!) > > code is exacting! > > > Publishable? RISC5 has been published. Are you arguing that this code > is "publishable" because it was published? Or are you saying this code > stands by itself as being publishable because of its > clarity? > Should this code be presented and taught as is? Actually, I was making a general comment on comments and how I (like to) write Oberon - not RISC5 - code. It was not specifically about RISC5. Whether the RISC5 code as published today is actually “publishable”, is .. apparently .. a topic of this thread..

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ALU 2015 and 2018
by Andreas Pirklbauer 13 May '22

13 May '22

> And of course, comments are never to be trusted. As Prof. Wirth says, the programs > themselves "alone contain the ultimate explanations." > > Cheers, > Paul Very true. And more: A misplaced comment can do more harm than good. Which is why I too tend to stick to the “minimalistic comment, but thorough documentation” philosophy. It has an additional benefit that is often overlooked: The act of writing sharpens the thinking and forces one to think much more thoroughly about the code. Writing correct code is already demanding enough, but writing publishable (!) code is exacting!

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Compiler Construction on projectoberon.net
by John Stout 10 May '22

10 May '22

Hello everyone I'm working on a compiler and emulation of the RISC processor detailed in the latest (?) edition of Compiler Construction by Professor Wirth from CompilerConstruction1.pdf (projectoberon.net) <http://www.projectoberon.net/wirth/CompilerConstruction/CompilerConstructio…> . I can't follow the Oberon code for the emulator in section 9.5 in the section handling memory instructions, which differs from Peter De Wachter's Oberon RISC emulator at https://github.com/pdewacht/oberon-risc-emu.git In Compiler Construction, once an instruction has been decoded as a memory instruction the address is calculated using adr := (R[b] + IR MOD 100000H) DIV 4; which (apart from the DIV 4) agrees with the code in oberon-risc-emu (which also sign extends the offset before adding it). If adr >= 0 then a load is carried out, and the N and Z flags set depending on the value loaded. However (and this is the bit I don't understand) if adr < 0 then a store is carried out, whereas in oberon-risc-emu u bit of the instruction is checked and if 0 a load is carried out and if 1 a store is carried out. Since I know oberon-risc-emu works, and that agrees with the settings for the u and v bits in Compiler Construction then I assume that must be the correct implementation, but is there an error in Compiler Construction or am I missing something very simple? All the best. John Stout

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.aoshome and Work Directory on an SD card in UnixAos.
by peter＠easthope.ca 12 Apr '22

12 Apr '22

Hi, For years I've kept the "Work Directory" in UnixAos on an SD card reformatted to ext2. Usage notes for flash storage commonly recommend against reformatting. Eg. https://wiki.laptop.org/go/Secure_Digital_card#Formatting So I've reviewed the possibility of the Work Directory containing a FAT file system. Access speed might be a concern for some requirements; not for me. An obvious small snag is the .aoshome link which the aos start script attempts to create. The FAT file system doesn't support links. The link appears in Configuration.XML allowing File Manager to access "Module Sources" and "Fonts". If aos fails to create .aoshome, File Manager doesn't show Module Sources and Fonts. A simple alternative to .aoshome is to hard code the location in two places in Configuration.XML. (The default location is /usr/aos.) I haven't noticed any other difficulty with a factory formatted SD card. Anything to add to notes to help a novice? Thx! ... P.L. -- mobile: +1 778 951 5147 VoIP: +1 604 670 0140 48.7693 N 123.3053 W

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Re: [Oberon] Compiler Construction PDF error
by John Stout 28 Mar '22

28 Mar '22

Ah, I didn't think to look at the source code on the site which would have been the last word. Many thanks. All the best. John On Mon, 28 Mar 2022 at 11:00, <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. Compiler Construction on projectoberon.net (John Stout) > 2. Re: Compiler Construction on projectoberon.net (Chris Burrows) > 3. Re: Compiler Construction on projectoberon.net (Joerg) > 4. Re: Compiler Construction on projectoberon.net (Chris Burrows) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 27 Mar 2022 11:07:43 +0000 > From: John Stout <cuspcomputers(a)gmail.com> > To: oberon(a)lists.inf.ethz.ch > Subject: [Oberon] Compiler Construction on projectoberon.net > Message-ID: > < > CAE7M_X1Z_QJpjVft+pGexpLpaq7FggUYgJNA4YfWtv4zHwLanA(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hello everyone > > I'm working on a compiler and emulation of the RISC processor detailed in > the latest (?) edition of Compiler Construction by Professor Wirth > from CompilerConstruction1.pdf > (projectoberon.net) > < > http://www.projectoberon.net/wirth/CompilerConstruction/CompilerConstructio… > > > . > > I can't follow the Oberon code for the emulator in section 9.5 in the > section handling memory instructions, which differs from Peter De Wachter's > Oberon RISC emulator at https://github.com/pdewacht/oberon-risc-emu.git > > In Compiler Construction, once an instruction has been decoded as a memory > instruction the address is calculated using > > adr := (R[b] + IR MOD 100000H) DIV 4; > > which (apart from the DIV 4) agrees with the code in oberon-risc-emu (which > also sign extends the offset before adding it). > > If adr >= 0 then a load is carried out, and the N and Z flags set depending > on the value loaded. > However (and this is the bit I don't understand) if adr < 0 then a store is > carried out, whereas in oberon-risc-emu u bit of the instruction is checked > and if 0 a load is carried out and if 1 a store is carried out. > > Since I know oberon-risc-emu works, and that agrees with the settings for > the u and v bits in Compiler Construction then I assume that must be the > correct implementation, but is there an error in Compiler Construction or > am I missing something very simple? > > All the best. > > John Stout >

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Re: [Oberon] Is anyone here a moderator or admin of comp.lang.oberon?
by Treutwein Bernhard 25 Mar '22

25 Mar '22

I tried to file a complaint, but nothing happened ... Sent from Nine<http://www.9folders.com/> ________________________________ Von: Chris Burrows <cfbsoftware(a)gmail.com> Gesendet: Donnerstag, 24. März 2022 19:43 An: ETH Oberon and related systems Betreff: Re: [Oberon] Is anyone here a moderator or admin of comp.lang.oberon? On Fri, Mar 25, 2022 at 12:03 AM Liam Proven <lproven(a)gmail.com<mailto:lproven@gmail.com>> wrote: I just tried to look at a post via Google Groups and got a warning: « Banned content warning Refer to the previous discussion here: [Oberon] Usenet group comp.lang.oberon is no longer accessible https://lists.inf.ethz.ch/pipermail/oberon/2021/015669.html Chris Burrows CFB Software https://www.astrobe.com/RISC5

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Is anyone here a moderator or admin of comp.lang.oberon?
by Liam Proven 24 Mar '22

24 Mar '22

I just tried to look at a post via Google Groups and got a warning: « Banned content warning comp.lang.oberon has been identified as containing spam, malware or other malicious content. For more information about content policies on Google Groups, see our Help Centre article on abuse and our Terms of Service. » -- Liam Proven ~ Profile: https://about.me/liamproven Email: lproven(a)cix.co.uk ~ gMail/gTalk/FB: lproven(a)gmail.com Twitter/LinkedIn: lproven ~ Skype: liamproven UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053

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Re: [Oberon] Re (2): Documentation for Gadgets;
by Treutwein Bernhard 24 Mar '22

24 Mar '22

Sent from Nine<http://www.9folders.com/> ________________________________ Von: peter(a)easthope.ca Gesendet: Mittwoch, 23. März 2022 16:25 An: oberon(a)lists.inf.ethz.ch Betreff: [Oberon] Re (2): Documentation for Gadgets; From: Dieter <d.gloetzel(a)web.de> Date: Wed, 23 Mar 2022 09:17:30 +0100 > I also recommend "The Oberon Companion" by Andre Fischer and Hannes Marais > ISBN 3-7281-2493-1 > vdf Hochschulverlag AG ETH Z??rich Thanks Dieter. At the top of each tutorial page is a green box [...] containing the sentence "Content is also available on paper." https://en.wikibooks.org/wiki/Oberon/ETH_Oberon/Tutorial [...] Currently abebooks.com lists 0 copies available. That can change any time. Obtaining the paper form is a matter of patience. just for clarification: André Fischers Tutorial is a precursor of the Oberon Companion by Fischer and Marais. The Companion is available in Oberon *.Text format in most versions of S3/ETH-Oberon and it is allowed to print one copy for personal use. Instructions how this maybe achieved are in the last paragraph of the Getting Started section [...] https://en.wikibooks.org/wiki/Oberon#Getting_Started

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Re (2): Documentation for Gadgets;
by peter＠easthope.ca 23 Mar '22

23 Mar '22

From: Dieter <d.gloetzel(a)web.de> Date: Wed, 23 Mar 2022 09:17:30 +0100 > I also recommend "The Oberon Companion" by Andre Fischer and Hannes Marais > ISBN 3-7281-2493-1 > vdf Hochschulverlag AG ETH Zürich Thanks Dieter. At the top of each tutorial page is a green box containing the sentence "Content is also available on paper." https://en.wikibooks.org/wiki/Oberon/ETH_Oberon/Tutorial "on paper" links to the paper book citation in the Oberon Bibliography. Currently abebooks.com lists 0 copies available. That can change any time. Obtaining the paper form is a matter of patience. From: Treutwein Bernhard <Bernhard.Treutwein(a)Verwaltung.Uni-Muenchen.DE> Date: Wed, 23 Mar 2022 11:50:59 +0000 > afaik the Oberon Companion is out of print, but an online version > should be available on every S3/ETH-Oberon. instructions how to create > a printed personal copy should be/were present in the Oberon wikibook. Bernhard, your section https://en.wikibooks.org/wiki/Oberon#Getting_Started remains in the title page. Your second papragraph refers to the three forms of the tutorial: the paper book, the electronic form in ETH Oberon and the pages in the wikibook. I've taken care to preserve Tutorial content as it was on the ETH Web server. Format or style is altered to the extent that Wikibooks creates the Contents list of a page according to heading markup. That can be suppressed but in my view the automated Contents is a benefit rather than detriment. MediaWiki allows an account to flag any page as watched. A convenient way to monitor changes. Vandalism hasn't been problematic. Criticisms and suggestions always welcome. Thanks, ... P.L. -- mobile: +1 778 951 5147 VoIP: +1 604 670 0140 48.7693 N 123.3053 W

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