Using a MIDISpeak kit by Highly Liquid and inspired by the dual-mode mod by Cedric Bodereau, this mod uses a DB25 cable, along with SPST and SPDT switches to toggle between Keypress and ROM play modes. It also feautures an on/off switch and an LED indicator light for the kit.

I’ve now written a How-to guide for wiring up a Dual-Mode Speak and Spell with the MIDISpeak kit.

You can find it on my (very old) blog here.