[Coco] MPI 2D rendering

[Gene Heskett]

On Saturday 28 March 2015 16:41:11 RETRO Innovations wrote:
> On 3/28/2015 2:38 PM, Bill Pierce via Coco wrote:
> > Jim, it looks really good. simple and to the point.
> > I ave 2 questions...
> > 1. What's the max length on the ribbon cable between the cart and
> > the board?
>
> Don't know.  I assume if the length is OK for ATA-6 IDE cables, it's
> OK for this.  80 conductor cable required (in my opinion).  40 will
> not have enough cross talk protection.
>
> > 2. Is there any particular reason for the wide spacng between cart
> > slots? I would think slightly closer spcing would reduce board
> > costs.
>
> Spacing was dictated by need to fit 64 pin TQFP package in between and
> space for standoffs (the base config would have nylon standoffs, which
> protrude above the PCB).  CoCo uses .961" opening size, and my spacing
> is 1.15", so .25" extra.  Someone with an MPI can check, but I believe
> it uses .2" spacing to allow the small bands of metal/plastic to
> separate slots.
>
> Jim

I am measuring .25" on the later MPI here Jim, and 4.33" for the width of 
the opening.  The cart separating & guiding dividers inside the lid go 
nearly to the PCB itself. Pretty well designed actually.  Spring loaded 
flaps to cover the opening when no cart is inserted.

Cheers, Gene Heskett
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