On Fri, Mar 06, 2015 at 05:23:29PM -0500, Jim Brain wrote: > <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head> > <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> > > </head><body> > > <p><br /></p> > <blockquote type="cite"> > <p>On March 6, 2015 at 9:50 AM Segher Boessenkool <segher@kernel.crashing.org> wrote:<br /><br /><br />On Wed, Mar 04, 2015 at 06:29:34PM -0600, Jim Brain wrote:<br />> I am not disputing that they are different, I just cannot understand why <br />> CSG would have taped out a simpler version of the 6526/8521 when they <br />> already had a die for the 6526.<br /><br />6526 and 852x are very different.</p> > </blockquote> > <p><br /></p> > <p>In technology, but not in function.  The 8521, as I understand, is a drop in replacement for the 6526.<br /></p> The 8521 is a completely new design, not a "shrink" of the 6526. It functionally is almost the same, yeah. > <blockquote type="cite"> > <p><br />> <br />About half of the 8521 layout is wasted space anyway; space is not the<br />issue. The 8520 has a TOD just fine as well -- but a binary counter,<br />not a BCD counter. A BCD counter does not take up much extra space,<br />either.</p> > </blockquote> > <p>From my CompE class days, I agree.  BCD is a couple extra gates on a binary counter.<br /></p> > <blockquote type="cite"> > <p><br />Presumably they just wanted a binary counter for the Amiga. The idea<br />that they made the 8520 and then the 8521 was an afterthought might be<br />true, too :-)</p> > </blockquote> > <p>I suppose they did this is crazy way just because they had the capabilities to do so.  But, man, what a waste of precious resources.<br /></p> > <p><br /></p> > <p>Jim</p> > > </body></html> What resources are wasted? Designers? Masks? Overhead? Segher Message was sent through the cbm-hackers mailing listReceived on 2015-03-07 16:00:05
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