[Coco] CocoFLASH Production

[Brad Dillon]

I apologize for the stupid question but how similar is this to the SDC?  Both store images such as games, etc...?


Date: Mon, 7 Nov 2016 20:34:23 -0600
From: RETRO Innovations <go4retro at go4retro.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Subject: Re: [Coco] CocoFLASH Production
Message-ID: <08bc761b-f7ae-c40b-b8c9-b7333f03a1e3 at go4retro.com>
Content-Type: text/plain; charset=utf-8; format=flowed

On 11/7/2016 8:12 PM, Mark McDougall wrote:
> On 8/11/2016 1:41 AM, RETRO Innovations wrote:
>
>> So, is there something else needed to support LodeRunner?
>
> Thanks for the explanation!
>
> I have to revisit my memory layout; to be honest I haven't yet
> designed how the cartridge mapping was going to work... 4KB banks is
> good, but I was planning on being able to swap in/out smaller windows
> within the upper 32KB address space. Lode Runner uses the entire lower
> 32KB for video memory, graphics data @$8000, code & game data
> @$C000... so I was thinking a 4KB window somewhere to be able to load
> level data - the original Apple II loaded this directly from disk
> sectors.
Well, I'd probably recommend a "bank in, copy ROM to RAM, and bank out"
approach.  Splitting the 32kB ROM space into individually addressed 4kB
virtual ROM slots would probably move me beyond my CPLD space.  I might
be able to create 4 8kB virtual ROM slots, and use 4 16 bit pointers to
set the bank for each of those slots:

$8000
$a000
$c000
$e000

But, that adds to the IO requirements (10 bytes instead of 4), and
requires quite a bit more setup for the simpler case of mapping in a
16kB or 32kB chunk of ROM into the CART space.

I guess let me know.  I can try it, if you feel the extra capability is
needed.
>
> And EEPROM for save game data is awesome! I was going to propose a
> 'standard' structure so that games from various authors could
> co-exist, like a tag/header+length for example, or maybe even a
> FAT-type scheme...
I think that's valuable.  I'd even suggest an API that hides the EEPROM
medium, so the same api can be used for Darren's solution, and others.

I was extremely surprised that my 15 macrocell homegrown SPI master works...
>
> Regards,
> Mark
>


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