[Oberon] Hobby FPGA boards

[Skulski, Wojciech]

Liam Proven [lproven at gmail.com] wrote Tuesday, February 11, 2020 11:37 AM

> (I'd like to get it running natively on Raspberry Pi.)

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? 

Since we developed our boards using ARM AM3358, (see www.FemtoDAQ.com for an example), I have a bit of experience. These ARM boards can be a hobby if you run a prepackaged examples, or slight modifications thereof. The progress is quick if you run simple Python for doing simple things, mostly following existing examples. If you want to achieve anything substantial then you are talking of many months of full time professional effort. Hobby is not enough despite intense propaganda.

>But would it be worth investigating if it might be possible to adapt the softcore to one of the mass-market FPGA hobbyist machines? That might be easier.

Examples:

• 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.

• 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.

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

There must be other similar boards, including the ones discussed on this mailing list. Not much progress in porting, though. I think I know why. The porting effort is substantial and the motivation for such a project is not clear.

In general, if you are looking at spending half a year of effort then the cost of the HW is pretty insubstantial. The attractiveness of a board should not consist of a low price and nothing else. There needs to be a match between the HW and the SW. I do not think these boards meet the needs of the Oberon System.

Wojtek