April 2021 - Oberon - mailman3.inf.ethz.ch

Re (2): Streams.
by peter＠easthope.ca 24 Apr '21

24 Apr '21

From: Charles Perkins <chuck(a)kuracali.com> Date: Thu, 22 Apr 2021 12:34:35 -0700 > I was just wishing for streams in Project Oberon so this is timely for me. Charles, can you elaborate on the motivation for Streams please. Why not just use Files directly? Can your requirements help to illustrate? Thx, ... P. -- VoIP: +1 604 670 0140 Bcc: peter at easthope. ca

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Streams.
by peter＠easthope.ca 22 Apr '21

22 Apr '21

Hi, Background Studying Oberon.Mail.Mod in ETH Oberon and use of Streams therein. I wondered about the purpose and necessity of the Streams module. Didn't find an explanation in Oberon. The comment in A2 is helpful. MODULE Streams; (** AUTHOR "pjm/be"; PURPOSE "I/O buffering and formatted writing and reading"; *) In Oberon.Mail.Mod ... PROCEDURE AddMsgHead(pos: SIGNED32); ... S := Streams.OpenFileReader(msgsF, pos); That opens the messages file, msgsF. Appears that the file is not closed before "END AddMsgHead". Is that good practice? Shouldn't msgsF be closed by the end of the procedure? Opening the msgsF at each reading of the head of a message seems inefficient. Why not open the file when the module is loaded? Then set the rider when necessary. Ref. https://svn.inf.ethz.ch/svn/lecturers/a2/trunk/source/ userid infsvnh.anonymous password anonymous TIA, ... P. -- VoIP: +1 604 670 0140 Bcc: peter at easthope. ca

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obnc can't find obnc-compile
by Duke Normandin 14 Apr '21

14 Apr '21

Could not figure out how to output real numbers in human-readable format using the vishaps compiler. So I installed obnc. From the CLI, I can run obnc, obnc-compile, etc without a problem, so there doesn't seem to be $PATH issue. However, when I try to compile my code: --> obnc tempConvert.obn sh: 1: /usr/local/bin/obnc-compile: not found obnc: build process failed It may be that I'm jinxed when it comes to using Oberon - in any flavour. :( -- Duke Normandin <dukeofpurl(a)gmx.com>

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Re: [Oberon] Simple REAL output (was: can't find obnc-compile)
by Chris Burrows 11 Apr '21

11 Apr '21

> -----Original Message----- > From: Oberon [mailto:oberon-bounces@lists.inf.ethz.ch] On Behalf Of Duke > Normandin > Sent: Saturday, 10 April 2021 11:54 PM > To: Oberon > Subject: [Oberon] obnc can't find obnc-compile > > Could not figure out how to output real numbers in human-readable format > using the vishaps compiler. So I installed obnc. > If the Oberon library you are using doesn't include a procedure to output real numbers exactly the way you want them to appear in your example it is quite feasible to do this yourself using library procedures that do exist. This would be an ideal introductory exercise for you to try. For example, follow these steps if you want to output a real number with 1 decimal place e.g. 98.6 1. Use the Oberon ENTIER function to get the whole part of the real number as an integer (= 98). 2. Subtract the result you got in (1) from the real number to get the fractional part (= 0.6). 3. Get the first digit of the fractional part by multiplying it by 10.0 (= 6.0) and use ENTIER to discard any other digits (= 6). Output the result you got in (1) using Out.Int: "98" Output the decimal point using Out.Char: "98." Output the result you got in (3) using Out.Int: "98.6" Regards, Chris Chris Burrows CFB Software https://www.astrobe.com/RISC5

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Oberon board, 2021
by Aubrey McIntosh 10 Apr '21

10 Apr '21

I have a windfall that will allow me to buy a hardware system that will support the Oberon / FPGA environment. I don't know the current status of board recommendation and such, and anyway it is a moving target. My last reasonably current status was in the Spartan board era. I would like to build some custom peripherals that are deeply coupled with my software. A representative example would be a 32-bit adder. An even more aggressive example would be a sha-256 stamper. I was somewhat active with Bitcoin long ago when a FPGA board was powerful enough for Bitcoin. I have also previously built a board with various A/D converters, with a view of using them in an undergraduate chemistry curriculum. The one restriction I can think of, I want to be able to program the hardware with homebrew and/or freeware. Previously, I have produced a board that could "in circuit program" a clone of itself. So, while not a professional, I am able to work at a level that pleases me. I think a group buy always makes sense. -- Aubrey McIntosh, PhD

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Re: [Oberon] obnc can't find obnc-compile
by Hans Klaver 10 Apr '21

10 Apr '21

Sorry, I meant to write: On 4/10/21 4:23 PM, Duke Normandin wrote: > (...) So I installed obnc. > > From the CLI, I can run obnc, obnc-compile, etc without a problem, so there doesn't seem to be $PATH issue. > > However, when I try to compile my code: > > --> obnc tempConvert.obn > sh: 1: /usr/local/bin/obnc-compile: not found > obnc: build process failed Possibly you have two separate installations of obnc. Try: $ which obnc-compile and: $ echo $PATH and notice if the path to obnc-compile is in $PATH -- Hans Klaver

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Re: [Oberon] In.Real not working
by Duke Normandin 09 Apr '21

09 Apr '21

@Dave Brown @David Lightfoot In.Open solved the problem! My petty program works a treat! [code] (* for voc compiler: voc filename.ob2 -M for obnc compiler: *) MODULE tempConvert; IMPORT In, Out; (* global variables declared here *) VAR choice:INTEGER; VAR temp:REAL; PROCEDURE fahr2cels(fahr:REAL):REAL; BEGIN RETURN 0.5556*(fahr - 32) END fahr2cels; PROCEDURE cels2fahr( cels:REAL):REAL; BEGIN RETURN cels * 1.8 + 32 END cels2fahr; BEGIN (* main program body*) choice := 0; temp := 0.0; Out.String("Temperature Conversion Utility");Out.Ln; Out.String("------------------------------");Out.Ln; Out.String("1 - Fahrenheit TO Celsius");Out.Ln; Out.String("2 - Celsius TO Fahrenheit");Out.Ln; Out.String(" - Enter your Choice");Out.Ln; In.Int(choice); CASE choice OF 1 : Out.String('Enter a number/temperature TO convert: '); In.Open; In.Real(temp); Out.Ln;Out.String("Your input was ");Out.Real(temp,3);Out.String(" Fahrenheit!");Out.Ln; Out.String("That's "); Out.Real( fahr2cels(temp),3);Out.String(" In Celsius!"); | 2 : Out.String("Enter a number/temperature TO convert: "); In.Open; In.Real(temp); Out.Ln;Out.String("Your input was ");Out.Real(temp,3);Out.String(" Celsius!");Out.Ln; Out.String("That's "); Out.Real(cels2fahr(temp),3);Out.String(" In Fahrenheit!"); ELSE Out.String("Sorry! Invalid Choice"); END; (*CASE*) Out.Ln; END tempConvert. [/code] Now I need to go and read up on how to output the temperatures in non-scientific notation. I'll find it!! Thx a bunch!! -- Duke Normandin <dukeofpurl(a)gmx.com>

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In.Real not working
by Duke Normandin 09 Apr '21

09 Apr '21

[code] In.Int(choice); CASE choice OF 1 : Out.String('Enter a number/temperature TO convert: '); In.Real(temp); Out.Ln;Out.String("Your input was ");Out.Real(temp,3);Out.String(" Fahrenheit!");Out.Ln; Out.String("That's "); Out.Real( fahr2cels(temp),3);Out.String(" In Celsius!"); | 2 : Out.String("Enter a number/temperature TO convert: "); In.Real(temp); Out.Ln;Out.String("Your input was ");Out.Real(temp,3);Out.String(" Celsius!");Out.Ln; Out.String("That's "); Out.Real(cels2fahr(temp),3);Out.String(" In Fahrenheit!"); ELSE Out.String("Sorry! Invalid Choice"); END; Out.Ln; [/code] My program compiles w/o errors. However, In.Real(temp) in each CASE alternative never seems to wait for user input. The entire block of code for the selected "choice" gets output with garbage (of course) values. I'm stuck! Again!! :) Thx for any clues! -- Duke Normandin <dukeofpurl(a)gmx.com>

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CASE statement
by Duke Normandin 09 Apr '21

09 Apr '21

Is it possible to have execute a block of code - BEGIN .... END for one or more CASE alternatives? I'm trying to simulate the following C code: switch (c){ case '1': printf("Enter a number/temperature to convert: "); scanf("%f", &temp); printf("Your input was %.1lf Fahrenheit\n", temp); printf("That's %.1lf in Celsius\n", fahr2cels(temp)); break; -- Duke Normandin <dukeofpurl(a)gmx.com>

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Oberon Learning Resource
by Duke Normandin 09 Apr '21

09 Apr '21

I'm enjoying reading the following: http://www.waltzballs.org/other/prog.html It's presented in a non-academic format, which appears to be more digestible for me. Good for newbies/old goats like me! :-D -- Duke Normandin <dukeofpurl(a)gmx.com>

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