BBC Micro on an FPGA | Hacker News Reader

BBC Micro on an FPGA

mikestirling.co.uk

74 pointsjacquesm20 comments

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Here are some more links to FPGA implementations of other home computers.

Commodore 64: (http://www.syntiac.com/fpga64.html)

Commodore PET: (http://www.stepinfusion.com/projects/pet2001fpga/)

Mac Plus (incomplete??): (http://www.bigmessowires.com/category/plustoo/)

Sinclair ZX81: (http://zxgate.sourceforge.net/zx81.html)

Sinclair Spectrum: (http://www.mikestirling.co.uk/zx-spectrum-on-an-fpga/)

MSX: (commercial product, I'm not sure if there's any code downloads) (https://en.wikipedia.org/wiki/1chipMSX)

The popular music ICs from a variety of machines in one box: (http://www.gadgetfactory.net/2012/06/introducing-the-retroca...)

EDIT:

Atari ST: (http://www.experiment-s.de/en/)

Atari bits n bobs (http://hardware.atari.org/vhdl/vhdl.htm)

A variety of different systems - Videopac; Adventure Vision; Colecovision; Bally Astrocade: (http://www.fpgaarcade.com/platforms.htm)

Hardware to support FPGA re-implementations of Amiga:

- http://en.wikipedia.org/wiki/Minimig (available from AmigaKit and a few others, or self-build - all schematics and source is available)

- http://www.fpgaarcade.com/ (shipping in very limited numbers; source/schematics have been promised "when ready" but are not available yet)

For both of these the FPGA does the bulk of the work. The Minimig cores have been ported to other boards (including Chameleon, mentioned below, as well as Xilinx dev boards I think). FPGA Arcade is also intended to support a bunch of other machines.

For the C64 and Amiga there's also the commercial C64 Chameleon (http://www.vesalia.de/e_chameleon.htm) that can plug into a real C64 and effectively replace most of it, or work as a standalone unit.

There's also the fairly popular Minimig (http://www.minimig.net/)

Hey! Don't forget the Oric-1/Atmos!

http://torlus.com/index.php?2007/11/13/206-oric-1-in-a-fpga-...

http://passionoric.free.fr/eng/download.htm

Sega: (https://github.com/danluu/sega-system-for-fpga)

The BBC micro was - and is - in many ways my favorite computer, ever. It had a structured basic, half decent sound and video, was expandable and had a fantastic keyboard.

My last one blew up a few years ago when I tried to see if it would still work (capacitors in the supply had gone, took the board with it). So this project is really tempting for me, I'll probably see if I can get this to work.

FPGA's are interesting, a kind of half-way point between software and hardware.

Did the capacitors destroy the supply? I managed to repair mine: http://blog.jgc.org/2011/11/back-from-dead-with-power-supply...

If anyone is tempted to try this without purchasing a suitable kit, make sure the parts are suitably rated. The 250V non-polarised C2 may be safety critical if it's a line to line or line to neutral capacitor - look for an "X" or "Y" marking (I can't tell from the damage evident in John's photos). Lots of information on line-rated caps at http://my.execpc.com/~endlr/line-filter.html.

Depends if they blew the traces off the board (that happen to my Master Turbo). Soldered on paperclip fixed it but was probably a small fire waiting to happen.

Yup, it's dead as can be :( But no problem, I'll find another one somewhere. This was a 'master 128K' version, my original became an embedded computer in an arts project at some point.

http://www.mkw.me.uk/beebem/ is a very, very good software "replacement" if you need a quick fix.

+1 for this. I've had it installed permanently for a few years and it works perfectly. You can even emulate Tube connected processors!

What are Tube connected processors? It sounds very intriguing.

The "tube" was the BBC micro's major expansion bus. Technically, it's a high speed asynchronous, buffered parallel IPC channel with no specific purpose.

Rather neatly, you could chuck a second CPU on the end of the bus and just use the host machine for IO. That made the machines EXTREMELY fast for the time. Many second CPUs were developed with different architectures from 6502, Z80, 32016 and the original ARM CPU (which was developed as a slave of a BBC micro!). I myself have owned a 6502 unit.

You can still get NEW tube second processors including a 64MHz ARM7 with 64MB RAM ( http://www.sprow.co.uk/bbc/armcopro.htm )

Pretty awesome for a 1980s 8-bit computer eh?

More info: http://en.wikipedia.org/wiki/Tube_%28BBC_Micro%29

The tube was a 'high speed' (for the time) parallel interface between the host (6502) and the co-processor.

There were several options for that, see http://en.wikipedia.org/wiki/Tube_%28BBC_Micro%29

I've written my own emulator. That was lots of fun to do.

At one point I had three of them, and I took them to bits. Did the same with a C64. What a waste.

More BBC fun: Here's a video of Vince Clark from Depeche Mode/Erasure in the mid 80s demonstrating midi sequencing on the extremely expensive UMI sequencer, which was basically a BBC master with a breakout box for midi.

http://www.youtube.com/watch?v=wQthcAK9kAg

The DLD6502 lighting desk was a similar canibalisation of a BBC in the 84/85 timeframe, from the people that would later become Flying Pig Systems.

This is great. I've been considering building a BBC master into an old ThinkPad chassis for about 10 years now. There's absolutely no way an efficient unit could be produced with "normal" beeb discrete hardware so FPGA would be considered. This is motivational at least!

With 16% cell utilisation, I reckon you could get a second processor and discrete TFT driver in there as well.

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