LambdaSpeak FutureSoft Edition

LambdaSpeak for the Masses, not the Classes

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Just like LambdaSpeak 3, but without the SP0256-AL2 and no onboard EEPROM PCM sample memory for autonomous PCM sample playing. Featurewise, mostly identical to LambdaSpeak 3, for a fraction of its price due to a much simpler PCB (no CPLD, no SP0256-AL2, no EEPROM etc.) Thanks to the one and only legendary CPC community hero, TFM - The Future Man, this dream finally came true! TFM initiated and sponsored the development and production of the first batch, so many kudos to this all time hero of the CPC community!

In a nutshell:


  • Perfect speech synthesis: Epson S1V30120-based natural speech 
  • DECtalk & Epson speech synthesizer modes
  • English & Spanish speaking, different voices, DECtalk singing, ...
  • MP3 player (from SD card)
  • Battery-buffered Real Time Clock with thermometer
  • Audio routing options for left / right stereo channel mixing & assignment:
    Audio from CPC speaker or external amplifier
  • High quality Amdrum PCM sample playing mode:
    at least Digiblaster quality
  • 70 new RSX commands for BASIC
  • CP/M support (speech, real time clock)
  • UART / Serial Interface up to 115200 Baud
  • MIDI IN and OUT
  • 8 easy to control GPIOs with LED Segment Bar for lightshows etc.
  • FutureOS support
  • 2 DKSs of software
  • Users Guide & Technical Reference Manual available
  • MX4 Connector
  • Help & Support by TFM & LambdaMikel
  • Open Source




  • R7: 2k; note: must match D1 LED!
  • R1, R3, R4: 10k
  • R5: Jumper Wire
  • Rn: 9pin Resistor Array / Network, A102J

Potentiometers / Trimmers:

  • RV1: 100 Ohm (Code 101)
  • RV2: 50k Ohm (Code 503)


  • C1, C2: 22 pF (Code 220); note: these must match Q1!
  • C3: 68 nF (Code 683)
  • C5, C6, C7, C8: 100 nF (Code 104)
  • C9, C10: Jumper Wire


  • U1: GAL 22V10(B,D)
  • U2: 74LS374
  • U3: 74LS244
  • U4: ATmega 644-20PU
  • Optional: DIL sockets for ICs (I recommend to use a socket at least for U4, to allow reprogramming)



Assembly Tipps

  • Don't forget the decoupling capacitors (104's) under the ICs!
  • If you are going to socket the ICs, then you will need to cut out the middle struts from the DIL sockets to accomodate them.
  • Use a fine side cutter to cut off the SQW and 32K pins from the RTC module




Adobe Portable Document Format - 153.47 kB - 06/17/2021 at 21:55



x-zip-compressed - 130.87 kB - 06/17/2021 at 21:54


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