Re: SX clocks generation

From: silverdr_at_wfmh.org.pl
Date: Fri, 3 May 2013 17:00:23 +0200
Message-Id: <AEC07B5A-1148-43D0-9802-9EEB0ACFD4B5@wfmh.org.pl>
On 2013-05-03, at 08:26, Nicolas Welte wrote:

> On 03.05.2013 01:33, silverdr@wfmh.org.pl wrote:
>>> >I had a moment of inspiration today (after Michau asked about the SX ROMs) to check how it is done in the SX (I thought it was like in the older 64s) and.. it occured that there are actually/two/  crystals piggybacked one on another and just three 74LS chips next to the passive stuff on the daughterboard called "clock unit". This means much more "generic" solution than the 8701, which I try to get rid of and even better in this terms than the hard to come by chips from the "discrete" clock generator in earlier C64 boards.
> 
> Jens Schönfeld already designed such a circuit. Unfortunately it is not for sale yet, afaik. It is based on the 74HC7046, which is like a MC4044 plus 74LS629 in one chip, and it is still available easily!
> 
> In an earlier message he mentioned the 74HC4046, don't know the difference.
> 
> Look here: http://www.forum64.de/wbb3/board2-c64-alles-rund-um-den-brotkasten/board4-hardware/49985-neues-miniprojekt-csg8701-replacement/

TNX - indeed, he (again :-) did what I was getting to do! I shall probably still try to check how the SX solution works. I am only afraid if the perceived simplicity is not the cause for the visual artefacts.

-- 
SD!
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Received on 2013-05-03 16:00:04

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