Re: How does the ZIP chip work?

["Bryan Parkoff" <none@nospam.net>]

<heuser.marcus@freenet.de> wrote in message 
1137093322.834215.67540@z14g2000cwz.googlegroups.com">news:1137093322.834215.67540@z14g2000cwz.googlegroups.com...
> I'm certainly not here to criticize anyone - especially not one with
> some rather creative ideas - but I strongly recommend that you read one
> or both of the following excellent books to better understand the
> hardware you are dealing with:
>
> "Understanding the Apple II" by Jim Sather
> "The Apple II Circuit Description" by Winston D. Gayler
>
> bye
> Marcus
>
Marcus,

    Thank you.  I have Understanding the Apple II + //e" manual already. 
Try to imagine if you replace ROM and RAM chips to support 4MHz instead of 
2MHz.  You will be able to run 6502 CPU at 2MHz on Apple II+ while video is 
still running at 14M with no problem.  It would affect Disk II, sound, and 
slots.  I have no idea if video scanner is affected that it is supposed to 
access RAM at 2MHz.  You imagine that it may not work!  It is like a hack 
without using accelerator card.

Bryan Parkoff