Re: [stella] 2600 on-a-Chip new site

Subject: Re: [stella] 2600 on-a-Chip new site
From: Adam Thornton <adam@xxxxxxx>
Date: Wed, 21 Aug 2002 21:53:30 -0500
On Wed, Aug 21, 2002 at 09:27:43PM -0500, Carlos Lopez wrote:
> I will be glad to help anyone to have a better comprehension of the TIA
> internals. But, as I mentioned on the project site, my plans are to design
> somewhere in the near future a portable 2600. That doesn't allow me to share
> the VHDL code at this time. Maybe when I have completed the design and the
> portable 2600 becomes a reality, I will release the code.

Fair enough.

I implore you, however, to make your portable 2600 a bit, well, more
than a 2002 recreation of the VCS.

I had had some ideas that would, I think, not take a whole lot of
silicon or discrete components and would make it a device I'd be more
likely to use.

a) RS-232 interface, so we could download a game from our PCs rather
    than simply loading it via the cartridge slot; this would also take
    a bit of logic to recognize the different bankswitching formats and
    implement them, but not a whole lot.  The Cuttle Cart does this.
b) A/D converter and audio interface.  Same argument, but for
    Supercharger games and/or WAV/MP3 versions of games.  Again, done by
    the Cuttle Cart.
c) Built-in "Cheetah"-like functionality.  Look at Bob Colbert's pages.
    Basically, once you've loaded a game, zap the bytes in it to modify
    its behavior; kind of a tiny hex editor written in 6502 assembly,
    letting you modify the memory contents.  If either a or b is
    implemented, it's really not necessary, but it's a cool hack.
d) Composite video out, stereo audio out.  It looks like you're already
    planning this.
e) Multicart support.  RAM is pretty cheap.  A smallish interface that
    let you load multiple games into RAM (with a or b above) and then
    select among them would make this design a little more useful when
    divorced from a VCS cartridge library.
f) Some sort of mechanism for debugging.  Since all the VCS hardware is
    emulated anyway, it seems like it shouldn't be that hard to
    externalize some interface to it for the use of homebrewers who
    want, effectively, a VCS hardware debugger.  I haven't given much
    thought to this, so I might just be babbling.

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