[Oberon] RISC.img format

[peter at easthope.ca]

>From chris at cfbsoftware.com  Sun Feb 14 21:28:09 2016
> Download the three PDF files that make up the Project Oberon book 
> ('Book Chapters x-x') from:
> 
> http://www.projectoberon.com/
> 
> The file system is described in Chapter 7. 

Right oh; ProjectOberon.System.pdf has been on my XO 1.5 
for over a year.  Read chapter 7 long ago.  As luck would 
have it, reread most of chapter 7 shortly before posting my 
question.

From: Paul Reed, paulreed at paddedcell.com, Sun, 14 Feb 2016 20:31:18 +0000
> What is a LONGINT in Oberon-88, is an INTEGER in Oberon-07 
> (which is 32-bit).
> ...
> What is an INTEGER in Oberon-88 ...

Thanks Paul.  I returned to the 2013 preface, page 5, 
and reread this sentence.
"1. The data types LONGINT, SHORTINT, and LONGREAL have been discarded, 
and with them the concept of type inclusion."

I deduce that implementation of the Native Oberon AosFS in 
Oberon 2013 is entirely possible but would require juggling 
to handle 16 bit integers (required in AosFS) in a language 
which provides 32 bit, but not 16 bit, integers.

>From chris at cfbsoftware.com  
> You do not have to decipher source code or try to read the minds 
> of the developers to find answers to questions like these. 

With absolute respect Chris, the answer to my question must be  
obvious to you.  Whereas I simply don't have adequate familiarity 
with the details to immediately recognize that representation of 
integers has constrained the implementation of the FS.  Even after 
reading Paul's reply, thinking was necessary.  Definitely I admire 
your agility in the subject.

Trivial observations from this discussion.

* Independent standards have benefits.  In this case, a specification 
of the 2013 FS, independent of the 2013 language or system, would 
facilitate implementation in another system.  In Native Oberon for 
example.

* Hypothetically, a solution to the "data transfer problem", 
mentioned by Wojtek, is an implementation of a FAT FS in Oberon 2013.  
Similar to FAT in Native Oberon.

Regards,                    ... Lyall E.






-- 
123456789 123456789 123456789 123456789 123456789 123456789 123456789 12
Tel +1 360 639 0202 
http://easthope.ca/Peter.html Bcc: peter at easthope. ca