[Coco] Multi-Pak ports

[Gene Heskett]

On Saturday 17 August 2013 20:20:07 Bruce W. Calkins did opine:

> 1: All three drive controllers should have the same hardware addresses,
> so the answer is NO; you should not even plug them into the MPI at the
> same time.
> 
> 2: Extended Disk Basic file tracking in RAM and its settings in ROM
> assume a single drive set.  Running drive sets in parallel would
> quickly lead to data corruption.  Changing the hardware addresses and
> descriptors in OS-9/Nitros9 might be doable.
> 
Don't forget that they need 2 4 byte wide decodes, with the std version 
needing $FF40-43, and $FF48, skipping the FF44-47 4 byte block.  One could 
with additional decoding, use two fairly easy because you could just move 
the address groups up by 4 bytes.  So that would occupy $FF40-$FF4C> 
But it would take new, full decoding logic installed in each drive cart.

The 3rd set would have to start a new $10 byte wide scheme.

I see red everytime I think of the headaches the incomplete decoding in the 
coco has caused us for the last 30 some years.  Idiocy, to save a $0.17 
chip.


> Bruce W.
> 
> ======================
> 
> 
> 
> ----- Original Message -----
> 
> From: "Bill"
> 
> >I searched over the post of the last 8 months to make sure I haven't
> >asked
> >
> > this before, but I didn't find anything similar. If it has been asked
> > and answered, I apologize.
> > 
> > I have 3 sets of drives and controllers. My question is can they all
> > be accessed through the MPI without having to power down and change
> > the port selector on the MPI?
> > 
> > In other words, can I access any of the other drive controllers simply
> > by typing some command to access the corresponding port?
> > 
> > Thanks
> 
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Cheers, Gene
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