Re: [Fwd: Re: Schematic MAX Basic cartridge for download]

From: Marko Mäkelä (msmakela_at_gmail.com)
Date: 2008-11-17 20:39:22

On Mon, Nov 17, 2008 at 10:41:09AM -0600, Jim Brain wrote:
> donni wrote:
> >This schematic on lycos: 
> >http://members.lycos.nl/ijmtu/hpbimg/MAX%20machine%20schematic.jpg
> >was reversed egineerd from a MAX machine I had sitting in front of me.
> >Why not use that one instead of a schematic full of errors, made from 
> >some unreadable copy?
> >Also the schematic on zimmers.net is not what is inside any max 
> >machine I ever seen, maybe it's the schematic for the very first 
> >version of the MAX machine ??
> I woulc concur.  Use this one (copyright holder agrees) and remove the 
> other one.

Better yet, archive the reverse engineered one as well, with a note saying
that it is based on real (and most likely revised) hardware.

In 1999, I posted some observations of the UltiMax and the original
schematic at http://www.funet.fi/pub/cbm/html/c64/ultimax.html
which now redirects to
http://www.zimmers.net/anonftp/pub/cbm/html/c64/ultimax.html
at Bo Zimmerman's site.  Feel free to copy that information to
other pages, in case there is something that is not mentioned at
http://www.floodgap.com/retrobits/ckb/secret/ultimax.html.

Please note that I have never seen a MAX machine, or even examined the
MAX BASIC cartridge ROM to verify my assumptions about the clock
speed and so on.  The above schematic on Lycos shows the clock divider
circuit that is familiar from the C64: the dot clock being 14.318181 MHz
divided by 14 and multiplied by 8.  In the schematic that Ruud made
readable, there are two crystals: the 14.318181 MHz for the NTSC color
clock and an 8 MHz one for dot clock.

	Marko

       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail pre-2.1.8.