[Coco] Interesting problem with multi-pak and CC3 and OS9L2 / Nitros9

Robert Gault robert.gault at att.net
Fri Sep 30 18:07:50 EDT 2016

John R. Hogerhuis wrote:
> I have an interesting problem with my multi-pak.
> Back in 90s when I did most of my color computering I did not own a
> multi-pak. At some point I bought one off ebay. I have already done the
> PEEK to verify that it has the PAL upgrade. It seemed to work fine for
> switching between rom paks.
> Now that I have a CocoSDC I finally got around to doing some serious
> testing and basically with multi-pak, the keyboard doesn't work under OS9.
> My keyboard works fine under DECB. But if I boot into NitrOS9 or OS9L2 then
> everything locks up at the prompt if I have my disk controller connected
> through the Multi-Pak.
> Also the cursor disappears.
> This does not happen if I connect a disk controller directly to the Coco 3
> and boot OS9 that way. Keyboard, cursor work fine in that case.
> Now, if I boot OS9 with Multi-Pak in the loop and then power off the MPI
> once everything is booted the cursor reappears and I can type (can't do
> much though since the disk drive becomes inaccessible with the multi-pak
> off).
> So is the keyboard handled differently under OS-9? Is it somehow more
> interrupt driven? And what could be happening with the Multi-Pak that would
> prevent the keyboard from being polled?
> Thanks,
> -- John.

That is not a problem I see with a Coco3, MPI, and NitrOS-9. Tell us which slots 
you use for your disk controller and other devices. Which version of OS-9 and/or 
NitrOS-9 have you tested?


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