[Oberon] Hennessy.Mod 64kB limit

Jörg joerg.straube at iaeth.ch
Wed Feb 19 08:43:00 CET 2020


SETs are indeed valuable. I use them a lot, when I have manipulate bits (eg graphics driver). But be aware: In Oberon-07 SETs are 32 bits. If you have a byte, SET can’t be used.
Jörg

> Am 18.02.2020 um 20:11 schrieb Frans-Pieter Vonck <fp at vonck.nl>:
> 
> Here an example of setting registers by set operations in Oberon07
> https://youtu.be/zlnj6FCY1tY?t=374
> (Ivan Denisov Oberon07 compiler in BlackBox)
> Greets,
> F.P.
> 
> Frans-Pieter Vonck schreef op 2020-02-18 19:34:
>> A few days ago I posted a comment on an item on Andreas Spiess youtube
>> channel, "What we should NOT do in 2020"
>> Spiess is an 'influencer' for programming ESP32 chips in arduino, "The
>> guy with the Swiss accent".
>> https://youtu.be/zFVM9xZR8KI
>> Me.
>> Quote from Edsger Dijkstra:
>> " [..]before really embarking on a sizable project, in particular
>> before starting the large investment of coding, try to kill the
>> project first, and
>> (ii) start with the most difficult, most risky parts first."
>> https://www.cs.utexas.edu/users/EWD/transcriptions/EWD13xx/EWD1308.html
>> Andreas Spiess
>> 2 dagen geleden
>> Killing the projet means say "no" ;-)  To start with the most
>> difficult part is no more in fashion these days with "agile" and "low
>> hanging fruits". But I tend to agree with Dijkstra.
>> 1
>> Oberoid Droidus
>> 2 dagen geleden (bewerkt)
>> @Andreas Spiess Unfortunately trial and error tinkering with IOT is
>> impossible while following Dijkstra's adagia. I feel more comfortable
>> with the ideas of Niklaus Wirth, a electronic engineer, not a
>> mathematician. He has developped an elegant language called Oberon07.
>> Oberon7  has an interesting approach to setting bits by using SET
>> operations. There is a commercial implementation of Oberon07
>> https://www.astrobe.com/  .  At ETHZ the development of Oberon for
>> micro-controllers is undertaken by Paul Reed.
>> Andreas Spiess
>> 2 dagen geleden
>> Nicklaus Wirth was one of my professors at ETH ;-)
>> 1
>> Oberoid Droidus
>> 2 dagen geleden
>> @Andreas Spiess The best! Hope there will be an Oberon Day at ETHZ
>> soon. A reason to visit Zwitserland and to check on my VM that is
>> hosted somewhere in the Alps. https://datacenterlight.ch/
>> I had this document in mind when I wrote the comment.
>> SET: A neglected data type, and its compilation for the ARM
>> https://people.inf.ethz.ch/wirth/Oberon/SETs.pdf
>> I think that bitwise manipulations by set operations is elegant.
>> Greets,
>> F.P. Vonck
>> Pablo Cayuela schreef op 2020-02-18 19:09:
>>> I'm on your side Wojtek, as a professor and a former student, I'm
>>> always praising Wirth's School but struggle with code, despite being
>>> Oberon, LoLa or Verilog in ETHZ repositories and followers.
>>> Too many parts of the codes are full of idioms known to an already
>>> involved developer of the tools, but hard for outsiders and newbies.
>>> I hope for they will follow the preached way.
>>> Prof. Pablo Cayuela
>>> On Tue, Feb 18, 2020 at 1:26 PM Skulski, Wojciech
>>> <skulski at pas.rochester.edu> wrote:
>>>> Joerg:
>>>> I am not questioning the code. I am questioning the coding
>>>> practice: avoiding any comments and writing bit masks explicitly in
>>>> hex.
>>>> I have learned how to clearly code bit masks from Cypress EZ-SB
>>>> Frameworks originally written by Anchor Chips. Translated to Oberon
>>>> it would look like this:
>>>> CONST Bit0 = 1; Bit1 = 2; Bit3 = 4; (* and so on, the same can be
>>>> written in hex *)
>>>> mno := inst DIV Bit20 MOD Bit4; (*  inst DIV 100000H MOD 10H; *)
>>>> So now we at least see which bit is being used without parsing hex
>>>> in mind. The intent of DIV and MOD can be explained in a comment.
>>>> All your explanations can be written in a comment. As a minimum, a
>>>> reference to NW papers could be given, with the paper title and
>>>> page.
>>>> I have written references to NW papers in my SysDef.Mod. I am
>>>> asking, why I could do in Rochester what has not been done in
>>>> Zurich, where this whole School of NW supposedly originated?
>>>> I do not want to present public speeches on the merits of NW
>>>> programming. I only want to see it done, in order for the code to
>>>> become clear rather than confusing.
>>>> W
>>>> --
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>>>> systems
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