[Coco] Midi and synther

[Gene Heskett]

On Friday 18 November 2016 14:44:35 Bill Pierce via Coco wrote:

> Michael, I think there was a program that allowed you to use the Coco
> as a keyboard to MIDI, but I don't think I've seen a copy. I don't
> even remember the name. I'm pretty sure it was an upload to Delphi and
> not a commercial product. On the other hand, Coco MIDI Pro will record
> MIDI in real time (MIDIPak Only), and if I'm not mistaken, allows you
> to input notes from the Coco keyboard in real time. Coco MIDI Pro DOES
> allow real time recording from the MIDI keyboard with full velocity,
> channel pressure, pitch wheel, etc. The problem with this whole idea,
> is the Coco can only interpret certain key combos. Some keys cannot be
> pressed together. I think they are keys in the same row or column as
> the coco cant read two keys in the same row or column. In this I'm
> talking about the internal keyboard matrix and not the physical layout
> of the keys. So chords are out. Only single note input would be
> possible. Also, no velocity would be possible as there's no way of
> computing how hard the key was pressed. Anyway, such a program would
> be very easy to write.
>
I wasn't even attempting to use the coco's keyboard, but the keyboard on 
the cz-101, which does send that out the midi out port, tested by 
slaving the mt-240 to it, the mt-240 played it too, with only the 
tinyest hint of the Floyd Cramer rolling keypress to the timing.  From 
the symptoms I was able to capture, even the deluxe 232 pack was being 
overrun at 31250 baud as after the first character, the data turned to 
mush. And stayed that way until a half second or so of all keys up 
allowed it to flush the rx buffer. I thought of installing a 16 byte 
fifo to act as a rubber band between the acia, and the coco3. and got 
about half done with a schematic. Doing it in discrete logic was just 
going to take too much real estate.  Today I expect we could do that in 
a 200k gate fpga & some wider max-232's for not more than a twenty in 
parts, farming out the board and small enough we could just about put 4 
midi jacks sitting flush with the top surface of the mpi.  The fifo? Not 
needed when the 16550 core has a 16 byte buffer. That core we could 
license but no clue how much a copy. I've other irons in the fire, but 
someone interested, like Ed, you Bill P. or Jim could probably have a 
working prototype in under 60 days.

Sell enough to pay the builder 50 cents an hour? Thats the $32 
question. ;-) And quite likely explains why it hasn't been done yet. 
:-(

> Bill Pierce
> "Charlie stole the handle, and the train it won't stop going, no way
> to slow down!" - Ian Anderson - Jethro Tull
>
> My Music from the Tandy/Radio Shack Color Computer 2 & 3
> https://sites.google.com/site/dabarnstudio/
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>
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Cheers, Gene Heskett
-- 
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