[Oberon] FPGA Oberon some news and a reply to F.P.

Jan Verhoeven jan at verhoeven272.nl
Tue Mar 4 10:34:40 CET 2014

eas lab wrote:

> PASCAL / Modula / Oberon were never intended to directly access bytes in
> absolute-addressed memory

Modula-2 was. It can address hardware addresses, eg video RAM using

VAR    screen [0B000H:0] : ARRAY .. , .. OF RECORD ch, at : CHAR END;

To mention just one. It also has low level functions that come close to 

 From the trio Pascal / Modula / Oberon, Modula-2 is the one best suited 
for operating system design. It has all the potential and the functions. 
It also has the dreaded LOOP/END construct that is the heart of all 
operating system inner loops.

> compared to which a minimal assembler..etc. would be trivial.

FST Modula for DOS had the assembler built-in. It was very convenient. 
One of the better Modula-2 variants.

> I used: #N->A , directly as the syntax.

Why not " A := N " ? That would have been readable and understandable by 

> Why write "seven" when "7" is more direct?

But you still wrote VAL ("7") ....

> The value of being able to 'extend' one OS/language with others, is well
> demonstrated by eg: Linux supports ETHO, which can call *nix utilties, and for really difficult problems that need 6 frames open on 1 screen, and ability to colour related text/concepts, only ETHO can do,the combination is powerful.

That's why I am still in doubt: why shell out an extra 200 eucks on FPGA 
gear, no matter how useful it may be for my education and ego? With the 
risk that an FPGA board maker halts production of the one board that the 
project is based on.

Or try to port Ceres / Oberon (or Lilith / Modula-2) to a small 
(possibly outdated) Linux kernel that takes care of all the nitty gritty 
like booting, multi tasking, network, printers, USB.
Perhaps even FreeDOS might be a very good alternative. I tried freedos 
recently and was impressed by what it offers. It's the best DOS money 
can buy. For free.
Or Kolibri OS. It's a kind of DOS but then 100% assembly and using flat 
real mode.

The FPGA project is very neat: it enables the student to create the 
hypothetical CPU that has been starring in Compiler Construction for 
over two decades now. But it also means that Oberon remains an island in 
an ocean of PC hardware, no matter how ridiculous that PC hardware may be.

-- Groetjes

Jan Verhoeven

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