[Coco] Re: 512k CoCo 3 with 6309 on ebay (Mike Pepe)

[Kevin Diggs]

Robert Emery wrote:
> 
>>>Dave wrote:
>>>
>>>>Nice machine Mike!
>>>>
>>>>Where did you pickup the 5V off the board for the fan and any current
>>>>limitation?
>>>>
>>>
>>>Right off the main power transistor. The power consumption is really
>>>quite low, though I usually like to run 12v fans off the unregulated DC.
>>>Only annoying thing about that is the busier the computer is, the more
>>>that unregulated supply sags, and the fan's speed drops. I guess its
>>>like an audio cpu load meter.
>>
>>Ok, so I was not hearing things :-)
>>
>>I hooked up a small 12 vdc fan also to the unregulated side of the power 
>>supply to try and avoid as much as possible overloading the already taxed 
>>regulated side of the CoCo 3 ps.<snip>
>>Depending on what I was doing while using the CoCo the pitch noise of the 
>>fan would definetively change, and I figured the pitch change was a result 
>>of a speed change due to a fluctuaing unreg 12Vdc as the load from the CoCo 
>>electronics shifted.
>>

	Wouldn't hooking the fan to the unregulated 12 supply actually reduce 
the power burnt up in the pass element (because the fan will cause a 
minute drop in the 12 supply thus reducing the voltage across the pass 
element)? I to have a small fan in my tre. I don't recall hearing it 
change speeds. And it is noisy. I wih I could find a way to put a larger 
diameter fan in there.

	What parts of a coco are going to change their power consumption under 
different loads? At least under the ROM, isn't the cpu always doing 
something? Do the sync and cwai reduce cpu power like they would on a 
modern processor?

					kevin