LambdaSpeak 3

https://github.com/lambdamikel/LambdaSpeak3/blob/master/history.md

Early breadboard prototype test (~ 2019) - 8Bit 8kHz 4channel PCM sample playback.

In 1985, I found a "Science Fiction Generator" flow chart diagram in a Science Fiction Short Stories Year Book. I forgot who the author of that flow chart was. I turned this flow chart into a BASIC program, and added SP0256-AL2-based speech in German to it. Here you go (sorry, German-only video):

"ComputerShopper" briefly featured LambdaSpeak 3 in their December 2019 issue.

Got permission from the editor-in-chief to publish a brief PDF excerpt, here you go: 

LambdaSpeak 3 in "ComputerShopper 12/2019"

Spent some more time Z80 / CPC coding, and the CPC synthesizer is now polyphonous. The CPC's AY-3-8912 has 3 channels. Also, 2 Amplitude Envelopes (ADSRs) were defined, and the envelope can be changed with a CPC key press:

MIDI IN is working! 

Here is a demo of MIDI IN working, using a simple "CPC MIDI IN Synthesizer" program that I have written in MAXAM Z80 assembler; sorry for poor keyboard playing abilities (I usually play the Guitar):

Note that the synthesizer (Akai Miniak) is only used as a MIDI controller / keyboard, and that the sound is coming from the GI AY-3-8912 sound chip in the Amstrad CPC. The chip supports 3 channels of polyphony and noise and (amplitude and tone) envelopes.

As you can see, latency is pretty low on the CPC side! It really requires a machine code program to get latency low enough though - BASIC is definitely too slow. For MIDI OUT, BASIC is sufficient. It was fun to write some Z80 code again - last time I did that was > 30 years ago.

Next, I will add 3 channel polyphony, velocity, and program change support to the CPC Synthesizer program. Stay tuned for updates. At this point, this is only CPC / Z80 programming though; the LambdaSpeak 3 firmware seems to be pretty final and stable by now, and the ATMega is almost full, so there isn't much space left.

You can find the MAXAM assembler source code of the "CPC MIDI IN Synthesizer" on the LS300.DSK on the LambdaSpeak 3 Github page. It also requires the latest firmware because I had to add a special UART / Serial Interface mode that allows "real time scanning and monitoring" of incoming Serial / MIDI Messages. 

I have updated the LambdaSpeak firmware to also support the 31250 BAUD mode required for MIDI. 

This inexpensive MIDI breakout board

 https://ubld.it/products/midi-breakout-board/

is perfect for the CPC. Not as bulky as some Arduino MIDI shields. 

Now that the hardware is finally final, it is time to work on the CPC software!

I am very happy proud and honored that TFM (aka Dr. Stefan Stumpferl), well-known in the CPC Scene for his fantastic FutureOS, is working on adding LambdaSpeak 3 support to his FutureOS, and he is also working on an RSX extension and a CPC ROM!

Check out his homepage for updates:

http://futureos.cpc-live.com/ 

Currently, he is working on RSX commands for the PCM EEPROM Sample Upload. EEPROM PCM Sample playing already works, as does the RTC. In addition to the commands he already wrote for the predecessor, LambdaSpeak 1.95 and LambdaSpeak 1.99. So the RSX extension / ROM is already quite mature and offers a lot of functionality.

I am thrilled that TFM continues to develop the LambdaSpeak 3 software. Thanks a lot, Stefan!! 

In the meantime, check out the BASIC programs that demonstrate some features of LambdaSpeak 3, but epspecially the EEPROM PCM Upload is not really feasible from BASIC (it takes minutes to upload a PCM WAV / sample file from BASIC into the EEPROM...)