[Coco] Need to Port NitrOS-9 6x09 L2 to N8VEM's New 6x0x Board

[Frank Swygert]

Date: Tue, 26 Nov 2013 19:37:47 +0000 (UTC)
From: Nick Marentes<nickma at optusnet.com.au>

Just found out about the 6309?! Where have they been the last 20 years?! 
If that's the case, they may want to be intruduced to the CoCo3.
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Where have YOU been the last 20 years Nick? People have been putting the 
6309E in CoCos for that long! Until Nitros9 came out with a version that 
took advantage of the 6309's added features (what, 10 years ago? or more 
like 15?) there wasn't much interest though.

To catch you up in a nut shell, Hitachi was a "second source" for 
several Motorola chips, including the 6809. In the case of the 6809 
Hitachi made some improvements in the core, but sort of hid them -- the 
6309 works perfectly as a 6809 when running 6809 code and of course is 
pin compatible. It's a CMOS chip instead of NMOS, so it has a lower 
power consumption than the original Motorola 6809. Apparently Hitachi 
didn't have permission to make improvements and Motorola wasn't pleased. 
Hitachi was banned from advertising the improvements. Some Japanese 
hobbyist discovered them and printed an article on them in the late 80s. 
A book on the chip by Chris Burke states that they had been available 
since 1988, but US hobbyist didn't get wind of it until early 1992. See 
http://cyberabi.ipower.com/Downloads/The_6309_Book.pdf. As a programmer 
you should find that book VERY interesting -- it's a programming guide 
for the 6309. I have to wonder if the Japanese hobbyist who discovered 
the extra features wasn't given a hint from someone who worked at 
Hitachi -- definitely not officially from Hitachi, maybe just someone 
who had worked on the chip, or some other "unofficial" leak...

-- 
Frank Swygert
Editor - American Motors Cars Magazine
www.amc-mag.com