Re: 1541IDE and 1541IDE-S -- and 8250IDE? (and 64IDE, now)

From: Jim Brain (
Date: 2007-12-14 00:49:52

RayBryan wrote:
> On Dec 13, 2007, at 12:55 PM, wrote:
>> On 2007-12-13, at 19:12, raycomp wrote:
>>> Jim,
>>> Is there a reason why the Commodore expansion port ground lines are 
>>> not used on the PCB layout (shown on the Schematic?
>>> Confusing to me is that some of the ICs do not show a connection to 
>>> VCC on the Schematic but the PCB layout has them connected.
>> I haven't checked the particular pictures but generally if the part 
>> (IC) has the common signals defined in its description, there is no 
>> need to connect all the obvious "physical" pins on the schematics. 
>> One connects only the "logical" components and the obvious signals 
>> are taken into account automatically.
> well, fine if that is the convention.  I was just pointing out that on 
> the connections on the plan and those on the board do not match.  Jim 
> asked for a review.
> --Ray
I appreciate the review.

In my haste to get the board pics up for viewing, I forgot to export the 
layout with the ground planes.  I have added them to  You'll see in the last two pics 
that the ground plane conencts all the grounds.  The two vias by the exp 
port are there basically to hook the two layers together, to ensure the 
two pins don't have to connect to each other through some long distance 

Some people connect all the grounds and then run the ground plane, but I 
let Eagle take care of it for me. 


Jim Brain, Brain Innovations                                      (X) 
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times! 

       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail pre-2.1.8.