[Coco] Coco-3 power and MPI questions

[Bill Pierce]

From what I understand, the reason to use slot #1 for the disk controller was "distance" and "timing". IIRC, the disk controller would "sometimes not work properly in any other slot due to critical timing required and the time it took the data to travel from point A to point B. Slot #1 is the first bus on the MPI therefore giving the controller the fastest bus speeds. It's the same reason that they suggest not to make y-cables over a certain length. Also it seems I remember seeing somewhere to put the disk controller first even on a y-cable (same reasons).
It seems like I read this in a Marty Goodman article in Rainbow somewhere... or as an answer to a question in his question/answer column.
I may be wrong, but that's the reason that seemes to come to mind when I saw the post.
 

Bill Pierce
"Today is a good day... I woke up" - Ritchie Havens
 

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-----Original Message-----
From: tim lindner <tlindner at macmess.org>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Wed, Oct 1, 2014 12:03 pm
Subject: Re: [Coco] Coco-3 power and MPI questions


On Wed, Oct 1, 2014 at 8:55 AM, Kandur <k at qdv.pw> wrote:
> Thanks Tim, is slot #1 'always on'?

Well, that is kind of ambiguous question. All 4 ports are always on.
If a device does full address decoding (not using SCS or CTS) it will
respond.

Plugging the floppy controller in the the back most slot (is it really
labeled #1?) is more of a convention than a requirement.

I can get you a schematic when I get home from work.

-- 
tim lindner

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