
MEGA65 – An open-source C65-like 8-bit computer - SwellJoe
http://www.m-e-g-a.org/mega65-introduction/
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unwind
That's a strange meta-link. The actual project is at
[http://mega65.org/](http://mega65.org/).

My first impression is that is seems awesome and like a great deal of fun. The
project itself is a bit ... weirdly presented though. There's no mention of
exactly what hardware (FPGA and board) is expected, just a link to download
the bitstream together with some paid subscription service for getting the
bitstream sent to me.

It claims to be open, but the initial impression is that it really doesn't
"want" to be open, sort of.

~~~
rspeer
mega65.org is a name that doesn't resolve in DNS at the moment.

~~~
unwind
[http://www.downforeveryoneorjustme.com/mega65.org](http://www.downforeveryoneorjustme.com/mega65.org)
doesn't seem to agree, that's weird.

Of course it worked (and works) for me, otherwise I wouldn't have found it,
and certainly not posted a link here.

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linker3000
Fascinating hi-tech/old-tech mix.

I am currently gathering the parts to build a 1979 vintage Acorn System 1
([http://speleotrove.com/acorn/index.html](http://speleotrove.com/acorn/index.html)).
I was aiming to use the original chips, although I am struggling to find the
IO/RAM INS8154 at a comfortable price - I am currently working my way through
some online stores that specialise in old stock without much success. If
anyone has a tube of them they no longer want taking up shelf space...!?

Plan B will be to redesign the I/O interface.

Plan C will be to emulate the whole lot in a PIC Microcontroller (including
the 6502).

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gbraad
For many years we have FPGA64[1] which as core has been ported to many boards,
such as Altera Cyclone-based DE0, DE1, the C-One and Turbo Chameleon to name a
few. Not sure about Xilinx-based, but I guess someone might have tried to get
it on a Spartan.

[1] [http://syntiac.com/fpga64.html](http://syntiac.com/fpga64.html)

~~~
SwellJoe
The Turbo Chameleon looks pretty awesome. It's kind of everything you'd want
to expand a C64, including an SD card drive, keyboard jack, VGA output (with
scan doubler)...but, it also has the ability to act as a C64 (or Amiga, or
Spectrum, or Atari 800XL) standalone. Really clever.

I have a C64 with a MSSIAH cartridge, which I've occasionally used for music.
But, my SD card drive was destroyed in a tragic vacuum cleaner accident, so I
don't have any way to do much other than use MSSIAH on the machine (no way to
save or load things).

So, the Turbo Chameleon actually might be sufficient for my needs. And, maybe
the FPGA on board can be made to run the C65 emulator, as well. I'd like it if
the MSSIAH folks made a port to work on the C65; that'd be awesome. The MSSIAH
can already use dual SID chips, but I haven't done the soldering to add a
second SID to my C64 yet (and I'm vaguely afraid to do that, since I only have
one C64 and no parts machines, so if I break it, it's back to ebay to find one
of the few remaining functional units).

------
SwellJoe
The author's blog has some great stuff about development:
[http://c65gs.blogspot.de/](http://c65gs.blogspot.de/)

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PythonicAlpha
FPGAs seem to be a great way to bring old machines to live again.

Question here as much I see from the first impression: How much will the
system be C64 compatible? Since the C65 was never really released, there
exists no real software for it and also the incorporated Basic V10 was
incomplete. So the C64 emulation is what really counts. Of course it could be
fun to play with a "16bit-6502" processor, but without or limited software the
fun is rather limited.

~~~
Narishma
There are a few options for playing with a 16-bit 6502 like the Apple IIGS or
the SNES.

~~~
cmrdporcupine
Or you could buy Western Design's 'Mensch computer', a full computer built
around a variant of the 65c816:

[http://www.westerndesigncenter.com/wdc/Mensch_Computer.cfm](http://www.westerndesigncenter.com/wdc/Mensch_Computer.cfm)

Or you could buy a single board machine from them, through Mouser.

Or just buy a 65c816 and breadboard it. The chip is still made and available
through Mouser. And can be clocked up to 20mhz.

~~~
linker3000
There's also the 65C02 from Western Design.

~~~
cmrdporcupine
OP was talking specifically about 16-bit 6502 variant

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bencollier49
It's odd, it feels more like conceptual art than a physical project, but there
is clearly some real design behind it.

More and more retro electronics do seem to be headed into the realm of art.
This particular project is retro-futurism, to all intents and purposes.

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sgt
Also see Paul Gardner-Stephen's blog entry "Introducing the MEGA65 Retro
Computer"

[http://c65gs.blogspot.de/2015/04/introducing-mega65-retro-
co...](http://c65gs.blogspot.de/2015/04/introducing-mega65-retro-
computer.html)

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myrandomcomment
For a working physical machine I would pay ~500 USD. It would be fun to play
with.

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blt
random question - with a screen width of 320, how do you deal with screen
coordinates in 8-bit variables?

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pkaye
You use 16-bit variables.

~~~
blt
So, 2 registers and 16-bit math in software? Was this common, or did games
find a way around it?

~~~
pkaye
Well the 6502 didn't have many registers but the CPU and SRAM were of similar
speed back then so most of the temporary values were stored in SRAM. Not too
long ago I did firmware on an 8-bit processor using the C language. It would
support 32/16/8-bit variables. You just have to choose the smallest one
possible to be most efficient.

