Re: Zip Chip programming info / disk image?

["Michael J. Mahon" <mjmahon@aol.com>]

RedskullDC wrote:
> Hi All,
>
> Can anyone point me towards more info on how the
> Zip chip (2+, 2e versions) are programmed, and/or
> a dsk image to drive the things?
>
> I've gleaned a certain amount from previous posts:
>
> 53ms timer on the /DEVSEL signal.
> Turning certain slots on/off for speed slowdown.

Whoops--the 53ms slowdown is on a "slow slot" /DEVSEL only.

I've seen the full (such as it was) text file on Zip Chip use
and internal "magic" addresses on the web, but it's been long
enough that I don't remember where--I'm sure someone does.

It is contained as a text file on the Zip Chip Utility disk,
and there are images of that in several places (asimov, etc.).

> Reason I ask:
>
> I'm tooling around with recreating the thing in an
> FPGA.
> I've already got a Spartan IIe board to emulate a
> 1MHz 65C02 ok (still testing...) with a jumper lead to
> the 65C02 socket in my 2e.
> I can post pics if people are interested, and source code
> when I'm satisfied everything is working alright.
> (Using one of these: http://www.burched.biz/b5x300.html
> that I already had here from another project.)
>
> I have a Spartan3-400 starter board from XILINX on
> the way, which is probably easier for most people to get,
> so it can easily be ported across to that.
> They're pretty good value for $120US. ($99 for the -200
> version S3)
>
> Next I'd like to get the board working as a zip-chip.
> Once that is working, the next thing will be to move
> the video generation into the FPGA, so as to be able to
> output standard VGA frequencies, and also to allow
> the "zip-chip" to run at full speed when accessing video.
> More colours/screen modes are a possibility.
>
> The 2e could easily be replicated in the FPGA entirely,
> but that would render all your peripheral cards useless,
> plus it would mean a lot more work re-inventing the
> wheel in many cases, which is why I have chosen to do
> things this way.

Good luck and keep us informed.

-michael

Music synthesis for 8-bit Apple II's!
Home page:  http://members.aol.com/MJMahon/

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