[Oberon] Hobby FPGA boards

[Liam Proven]

On Tue, 11 Feb 2020 at 18:55, Skulski, Wojciech
<skulski at pas.rochester.edu> wrote:
>
> Which one? I do not know the RPi processor, but I know the BeagleBone one which is a bit simpler than the recent Rpi. Its TRM is over six thousand pages. Are you sure it is a realistic battle to fight for an small army consisting of one soldier?

I am not at all sure, no!

But there are already Oberon compilers for ARM.

My thought was, Oberon itself for Raspberry Pi Zero / Zero W:

https://www.raspberrypi.org/products/raspberry-pi-zero/

That's ARMv6

If that was successful,  to target A2 to the RasPi 3/3+ -- they have
quad-core ARMv8 chips and very similar hardware. The 3B+ is clocked a
little faster, that's about all.

But as they are multi-core, Native Oberon can't handle all the cores. A2 could.

I do not expect full support for the VideoCore GPU -- the drivers are
only available as a proprietary Linux BLOB.

A bootloader is not necessary as the GPU does that for you.

The core needs are USB and networking support.

Some of this exists already inside ETH but I think they are too busy
to release it. :-(

There are already multiple FOSS OSes for this OS, so there is code out
there to study. The boards already run:
* Linux (obviously)
* FreeBSD
* NetBSD
* Plan 9
* Acorn RISC OS
* Ultibo (an Object Pascal compiled environment)

Ultibo does not yet support the RasPi 4 so I was hoping to ignore that for now.

>> • MiST -- https://amigastore.eu/en/358-mist-midi-fpga-computer-with-midi-add-on.html
> It has SDRAM, whose firmware is complicated. You will need caching. A simple CPU w/a cache will be marginal with SDRAM.

OK, but this has already been solved for its Atari ST, Amiga and so on
cores, and the code could be re-used. It's FOSS.

> • Its successor, MiSTer -- https://github.com/MiSTer-devel/Main_MiSTer/wiki
> It is based on a Zynq-like SoC, which has those ARM chips in silicon whose description takes thousands of pages. This board is meant to run Linux. It is not a simple hobby at all.

Would an Oberon machine need the ARM?

I must point out that these _are_ hobbyist machines.

> • ZX-Uno -- http://zxuno.speccy.org/maquina_e.shtml
> Not enough RAM.

OK, but then there may be comparable devices. The TBBlue, basis of the
commercial ZX Spectrum Next, is also FPGA-based.

The hobbyist community are emulating lots of things on these.
 - IBM S/360: https://www.vaxbarn.com/index.php/collection/22-360
 - DEC PDP-11: https://opencores.org/projects/w11
 - DEC PDP-10: http://fpgaretrocomputing.org/pdp10x/
 - DEC PDP-8: https://jeelabs.org/2016/10/pdp-8/l--df32-disk-on-fpga/

There is a lot of activity on this front.



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