[sdiy] Casio XW-PD1 nonsense

[Benjamin Tremblay]

Hi, just asking in case anyone knows about how to get sampled sound to play via external MIDI controller.

I got this Casio “trackformer” thing in hopes I could trigger its sounds with MIDI.
I added 5-pin MIDI to it and it works. 

However, its MIDI implementation is sketchy. Very little is written about this thing. I know it neither sends nor receives MIDI clock or SPP. 
I don’t care. What I care is if I can trigger XW-PD1 sounds with an external device. 
It seems like it sort of works, but basically I can only trigger ROMpler sounds, not the “XW Synth” mono synth, and not a “bank” with custom sampled sounds assigned to pads. 
In other words it can trigger “general MIDI / XG” sounds but it cannot trigger “pads” with the settings I assign to them. 
I will re-read the MIDI implementation page, but I get the feeling that both the MIDI implementation and a dump of MIDI output will not reveal anything about how it works. 
I do not think I can select a program/bank that is “custom” content via MIDI. I admit I don’t understand if I can even address sampled sound by bank/patten/pad type/ pad in midi at all.

I can get it to play a bank with a sample if the bank is a polyphonic voice of just one sample. However, if I send a MIDI program change to that channel I can never get that sound back unless I reboot. 
I cannot select a drum kit where I added custom samples to the kit. It only plays the default sounds of the kit, as if when I added a sample I was simply “covering” the native sound with sample via some kind of internal mapping that is only driven by hitting a pad.

So, it seems, the XW-PD1 is a sports car red spaceship that when played by an external sequencer, sounds like a multitimbral home keyboard from the mid 2000s. Granted it has some decent synth sounds and a 909 kit.

I can only imagine what it was like to work on this product. Let me guess.
A product spec that was written and then abandoned. 
An internal team that did the microcontroller and UI coding. 
A DSP team that included consultants who programmed the Dream chip and did the bare minimum amount of work to take a “tone module demo” repo and make it handle the samples and effect pads.
The Dream chip is controlled by a TTL level MIDI pin, and the DSP team pushed back on any feature request that required anything but standard MIDI commands, saying it was “impossible”.

Benjamin Tremblay
btremblay at me.com
Carlisle, MA 01741