[Coco] Kicking the Z-80 butts...

[John W. Linville]

On Tue, Apr 28, 2015 at 04:27:19PM -0400, John W. Linville wrote:
> On Tue, Apr 28, 2015 at 02:20:41PM -0500, Zippster wrote:
> > Well, it is late ‘70s technology.  Earlier that decade the first microprocessors were introduced.
> > I guess the 6847’s major weak point is probably the terribly limited 32 column text display.
> > Other VDGs of the time were pretty low-resolution as well.  But you have to remember there 
> > wasn’t much resolution available on the display devices either, even if you would have had the silicon for it.
> 
> IMHO, the only real problem with the 6847 is the available colors.
> Even the individual colors aren't terrible, but the inflexible
> combinations seem to have been chosen by a colorblind sadist...
> Only being able to have green or white (depending on color set chosen)
> for the background color is also...painful.
> 
> The 32-character line width in text mode isn't great, but it is a lot
> better than the VIC-20's 22×23 text layout.  And at least with a power
> of 2 for the line width, you don't have to do the arithmetic gymnastics
> required by the Apple II when computing a character's offset in memory!
> 
> Overall the resolutions for the 6847 aren't too bad given the time
> it was released.  The fact that it was "off the shelf" should have
> made it very attractive for a variety of uses.  In fact, I know of at
> least one industrial "over computer" that shows-up on eBay from time

"oven computer"

> to time that used it.  If the color palette had been more flexible
> then I'll bet it would have been much more highly regarded...
> 
> 
> > Video is just a massive amount of data once you start to move past 300x200 or so and just a few colors.
> > Even the 6809 will start to choke pretty quickly heading in that direction.
> 
> Which is why the coco3 probably should have had a blitter...
> 
> > Although it is a pretty incredible 8-bit CPU with an interesting story behind it.
> > It should have been more popular.
> 
> How popular were Defender and Robotron? :-)
> 
> > 
> > - Ed
> > 
> > 
> > > On Apr 28, 2015, at 1:28 PM, Gustavo Ranaur Schoenaker <ranaur at ranaur.net> wrote:
> > > 
> > > Really amazing.
> > > 
> > > The more I know the 6809 the more I think the problem with the chip was no
> > > t the processos, but the 6847. Maybe it was the reason Tandy made the GIME
> > > chip on CoCo 3. Video is really the upper limit of the plataform. At those
> > > times the video chip make a huge difference.
> > > 
> > > Nice job Luis!
> > > 
> > 
> > 
> > -- 
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> 
> -- 
> John W. Linville		Someday the world will need a hero, and you
> linville at tuxdriver.com			might be all we have.  Be ready.
> 
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-- 
John W. Linville		Someday the world will need a hero, and you
linville at tuxdriver.com			might be all we have.  Be ready.