[Coco] USB cable powered CoCo 3 ???

[Steve Bjork]

Not a good idea to drive power into the CoCo on the +5 volt line of the 
expansion slot.

First, (as pointed out) the CoCo uses more than the 1/2 amp supplied by 
the standard USB port. (There are USB ports that supply more power , 
like USB 3.)
But the real problem is damaging the salt chip.  This chip is not only 
the 5 volt controller, but also supplies non 5 volt power to other 
devices in the CoCo like the RS-232 port.

I would check out the RS-232 port and Cassette Port to make sure they 
are both still working that CoCo.

Steve Bjork

On 5/26/2010 9:38 AM, Roger Taylor wrote:
>
> What'ya make of this one...
>
> I built the first CoCoNet USB Serial Pak a few days ago which is the 
> Drive Pak board with a USB board attached in the same place.  Run a 
> cable to your PC, fire the server up, and you've got 115200 bps or 
> 230400 bps virtual drives and NitrOS-9, etc. the same as you'd get 
> over a bitbanger cable or an RS-232 Pak or bluetooth pak.
>
> At first I connected the USB board's 5v to my serial board's 5v pin, 
> and lo and behold when I plugged the USB cable into the PC... the CoCo 
> came on.  The monitor lit up and there she was, flashing cursor and 
> everything.
> I remember having two thoughts:  Oh Crap, and Hey, this might be 
> useful!  The video was a little dimmer on Roy's adaptor and my LCD 
> monitor, but everything seemed to function.  Turning the CoCo on 
> brightened up the video.  Turning the power off dimmed the video back 
> a little, and of course unplugging the USB cable turned the CoCo off.
>
> So.... my question is: what did I stumble across here and has anyone 
> had any experience with powering the CoCo through the expansion slot, 
> and if so, what are the power requirements and how stable is it?
>
> I've got a 512k upgrade in the 3 so I assume the power is enough to 
> feed all these chips.