[Coco] An 8-Slot Multi-Pak Design for my Color Computer

[Frank Swygert]

The main problem is with the early cartridges. Later ones have the power 
land slightly shorter than the other. When the cartridge isn't inserted 
or detached straight out and all the lands are the same length the power 
land can short over to the adjacent lands, sending +5V over a line that 
wasn't meant for it -- or +12V in the case of the CoCo1 and possibly 
early Dragon. Look at your carts real good and see if one land isn't 
shorter than the others. ------------ Date: Mon, 05 Jul 2010 16:06:20 
+0100 From: afra at aurigae.demon.co.uk Quoting "Little John 
(GIMEchip.com)" <sales at gimechip.com>: >> A huge mistake in not buffering 
the data bus on the main board. >> If you are running a stock Coco3, you 
do run the risk of damaging >> the MC6809E and the HD6309E if the board 
becomes detached while >> powered up. > That's easy enough to fix. 
However, even with the databuffer on the > main board, detaching while 
powered up could cause damage, > especially if it were knocked sideways 
- zap.

I keep hearing this over and over again, but have not found the 6809E
any more suceptable to damage in this way compared to say a 6502 or a
Z80, and believe me I've done enough (un)intentional
plugging/unplugging things with the power on. I don't recall
killing a 6809 yet.....perhaps I have been lucky.

Mind this is in a CoCo 1/2 or a Dragon 32/64, so it may be different
in the CoCo 3.

-- 
Frank Swygert
Publisher, "American Motors Cars"
Magazine (AMC)
For all AMC enthusiasts
http://www.amc-mag.com
(free download available!)