[Coco] Sound/Speech Cart

[R. Allen Murphey]

On Thu, 2025-02-06 at 09:23 -0500, Alex Evans via Coco wrote:
> That is inconsistent with the code you presented (which works). WDELAY
> waits for BUSY*, then it calls BDELAY2.


Go with whatever the code does - my brain is swiss cheese when I am on-call at
work (like this week.


> The way I read the docs, BUSY* should be low when the PIC is busy (not
> ready to accept input). However, as your code takes into consideration,
> this is not the case. Maybe I misunderstand the docs.


You do have to wait until its ready for the next load.
I thought I was polling the busy down there somewhere in the delay thing.
Maybe not - it was years ago and I'd need some sleep, coffee, and a close read
again to try to get it all back in brain.


> 
> Was the ~250us delay determined experimentally or some other way?


Probably experimentally after some bad math on an old napkin somewhere.


> 
> Oh, the switching the MPI at the beginning of the code is unnecessary as
> the SSC is mapped at $ff7d, $ff7e which is not in the range $ff40-$ff5f so
> it doesn't even have the option of using SCS*


My good old cargo cult boiler plate copy and paste.

If you don't need it - leave it out.


I really ought to add my standard disclaimer on that page I guess:

"The author of this page has no idea what he's down, and flails and fails until
It Works for Him(tm) - your mileage or kilometerage will vary."

I sent it hoping it might help - and hoping it doesn't cause more confusion.


Anything you find that can be better - add or change it and post it up on your
site for the next folks to learn from better.

Looking at it quickly this morning, I should have probably used something like
a single subroutine to just take a register and value - do the wait - send the
stuff - then return rather than the nasty "wait, wait, wait" every other line.

It was a quick and dirty test to play the scales and is not at all good code to
emulate.

Might be fun to put it into some LLM code thing and say "write better code"
about 5 times in a row to make it spit out something more usable?

Anyway - you're on the right track - follow the data sheet and service manual
where you can - and hopefully there's enough clues in the stuff I wrote to get
the rest of the way.

-- 
R. Allen Murphey <exile at weylan-yutani.com>
Weylan-Yutani Corporation
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