The Making of a TRS-80 Voice Synthesizer - Talker/80

Published on Mar 14, 2020 Michael Wessel

via Michael Wessel, who brought us the Speak&SID:

"New dimensions in voice synthesis for the iconic Trinity computer from 1977!

Talker/80 is a new speech (voice) synthesizer for the TRS-80 Model 1. It offers DECtalk-based natural sounding speech, and can emulate the "official" TRS Voice Synthesizer as well as the VS-100 Alpha Products voice synthesizer. The original software runs without changes / patches. Both the VS-100 and the TRS Voice Synthesizer utilized the Votrax SC-01 speech chip. The SC-01 is "emulated" by means of DECtalk here (phoneme mapping).

Everything is open source, including the firmware sources and Gerbers:

https://github.com/lambdamikel/Talker-80"

Speak&SID - CPC MIDI IN SID + AY Synth

Published on Dec 4, 2019 Michael Wessel

"Turn your CPC into a powerful MIDI IN SID + AY Synthesizer!

A new mode has been added to the Speak&SID firmware - the MIDISID mode.

In this mode, Speak&SID can receive MIDI messages over its UART header to which a 10 $ MIDI breakout board is connected via Dupont cables. The Microkorg is used solely as a MIDI controller here (no sounds from the Microkorg). The incoming MIDI messages are then received by the CPC by reading the Speak&SID serial buffer byte by byte, and analyzed and translated into (polyphonous) notes for the internal CPC AY 3-8912 soundchip. At the same time, these notes are also sent to the (ARM)SID chip on the Speak&SID card, which is then also playing the received notes (currently only 1 voice - but for the AY we are using all 3 voices). With a little bit of additional work on the CPC machine code program, all of the SID's capabilities will be controlled via MIDI and/or the CPC keyboard keys in the near future, hence turning a CPC with Speak&SID into a powerful and inexpensive, versatile SID + AY 3-8912 MIDI IN realtime synthesizer. It is even possible to add one more soundgenerator to the mix - the SpeakJet chip is also a 4channel sound synthesizer! Interestingly, as you can hear, the SID and AY sound chip are slightly detuned from each other. Not sure why this is... maybe I need to tune the SID or AY frequencies a bit? Or maybe that's an ARMSID inaccurarcy? Have to try with my real 6581."

Speak&SID CPC - 2nd Demo, Line Out Recording + LEDs!

Published on Nov 9, 2019 Michael Wessel

"This time, a line out recording of Speak&SID CPC. Last video was taken from the camera's mic. Speak&SID's GPIO LEDs are controlled by the CPC, not the firmware. The 4 LEDs, from left to right, are the GATE bits of the corresponding SID cannels, and the 4th LED indicates changes in filter resonance. As the LEDs are controlled by the CPC / SID Player software, it is also possible to turn this LED display into a volume level indicator display, or other kinds of "lightshows". It is easy to patch the ASM for that (all the SID registers are modeled in software there).

In the meantime, the 2nd PCB revision boards arrived. So I should be able to ship out the first Speak&SID cards early December."

Amstrad CPC Speak&SID - First Demo of SID Player

Published on Nov 2, 2019 Michael Wessel

"First demo of Speak&SID with the DaDMaN's version of Simon Owen's SID Player. Thanks to DaDMaN from the CPC Wiki Forum for sharing his branch of this player with me, which he had already customized for the CPC! Indeed, it was very little effort to get it running with Speak&SID. I only needed to change the output port and a couple other bits. And worked out of the box, to my surprise! And now - enjoy RoboCup and Commando on the authentic SID 6581.

In case you should be wondering why the sound volume goes low and sounds tinny for a couple of seconds at some point in the video - Speak&SID also feeds into the CPC's internal audio speaker, so at that point I am turning off the amp and let the CPC speaker roar for a bit."

Some additional info in via Mechael Wessel:

"I am cooking up a SID soundcard for the Amstrad CPC

Maybe of some interest to SID / CPC lovers?

'CPC Speak&SID' is a SpeakJet-based speech synthesizer for the CPC, and a SID sound card! It works with the original SID chips, but SwinSID and ARMSID are also valid options. The video shows the original 6581 in action.

The sources for CPC Speak&SID will be made open source soon. The production costs for the card are in the 50 $ range (without the SID chip of course - builders have to source one themselves) Speak&SSID uses the SpeakChip chip for the speech synthesizer, an ATMega 8535 at 16 MHz as the microcontroller, and a Xilinx 9536 CPLD. The SID chip is connected directly to the CPC address and databus though; the CPLD generates the 1 MHz clock signal from the CPC's 4 MHz clock, as well as the other control signals such as R/~W etc.

Unlike the Commodore, the CPC uses IO ports instead of memory mapped registers for hardware interfacing. Hence, the 29 SID chip registers starting at address &d400 to &d41c in the C64 memory are mapped to the CPC's Z80 IO ports &fac0 - &fadc. C64 SID BASIC programs can be ported easily to Speak&SID, simply by replacing the POKE's (PEEK) with OUT (INP) commands, and by adjusting the SID base address.

For the SID Player shown in the video, I am using a version that was already customized by DaDMaN from the CPC Wiki Forum, and it is based on Simon Owen's SID Player for the Z80."