Re: 1 MB image for VIC-20

From: Marko Mäkelä (msmakela_at_cc.hut.fi)
Date: 2001-02-16 08:11:45

On Thu, 15 Feb 2001, MagerValp wrote:

> MM> Yep, if you remove the duplicates archived on funet, you'll get
> MM> around 1,4 megabytes. When compressed with pucrunch, the whole lot
> MM> takes about 8 kilobytes less than a megabyte.
> 
> Incidentally, that's just what you need for a little selection menu 8)

Exactly.  I fiddled around with the stand-alone pucrunch uncompressor
(thanks for the hint, Pasi!).  The menu and the uncompressor code will
probably take around 500 bytes, and each menu entry could be fitted into
13 bytes, using sixteen 5-bit characters, and 3 bytes for the address of
the compressed data, plus some flags.

> Is there a good way of getting the 6821 to a known default state on
> powerup?

I think it has internal pull-ups.  But there is another possibility:
programmed logic.  A friend of mine is working in the electronics research
and development lab of a big company, and he has access to all kinds of
fancy equipment.  And since it was his idea to build the cartridge, he
will build it.  He said that making a few PCBs for private use shouldn't
be a problem.

> PS: if this projects gets to the stage where you make a couple of
>     PCBs, I'd love to be in on it :)

I'll keep you (cbm-hackers) posted.

	Marko

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