[Coco] n8vem-sbc (was Midwest VCF)

gene heskett gheskett at wdtv.com
Wed Sep 28 11:32:28 EDT 2011

On Wednesday, September 28, 2011 11:13:30 AM Frank Swygert did opine:

> http://n8vem-sbc.pbworks.com/w/page/4200908/FrontPage
> Scroll to the bottom and you'll see that there is a 68000 board also.
> Might be the thing for those who always wanted a 68K based computer. Now
> we need a 68K version of Nitros-9...
> I also see that the 6809 cards ARE NOT S-100, but are the metric
> "Eurocard" format (60 x 100 mm, which appears to be a 3U card, 3x32 [96
> pin] connector... I'm assuming). Nothing wrong with that, just passing
> it along. There is an S-100 based version of the project, but no 6809
> boards listed, just a 68K.

And that is for the 68000.  While that chip was ground breaking at the 
time, it was NOT a full 32 bit chip, its address register is only 24 bits, 
limiting memory to 16 megs.  And the S-100 bus is so slow it limits the 
speed just as surely as the similar zorro did in the amiga's.  A hair over 
7 mhz.  If they were going to design a 24 bit board, they could have used 
the 68070, which is the 68000 with some of its peripherals built in.  I 
believe it is also faster so the zorro/S-100 bus would need to be replaced 
with pci, some versions of which can run at 66 mhz if the card supports it.

However, it may be that the SSC68070 is historical, google cannot find 
references that don't start with 'was'. :(

Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
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NOWPRINT. NOWPRINT. Clemclone, back to the shadows again.
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