<gallery caption="MHT Speech">
File:MHT-sintetizdor_de_voz-001.jpg|Outside
File:MHT-sintetizdor_de_voz-003.jpg|Inside
File:NoPicture.gif|Part number on GI chip
File:NoPicture.gif|Part number on oscillator
</gallery>
<gallery caption="MHT Speech Synthesizer Layout, thanks to Jose Leandro">
File:MHT Speech Synthesizer - PCB Front.png|PCB Front
File:MHT Speech Synthesizer - PCB Back.png|PCB Back
File:MHT Speech Synthesizer - PCB Chips.png|PCB Chips
File:MHT Speech Synthesizer - PCB Complete.png|PCB Complete
File:MHT Speech Synthesizer - Layout.png|Layout
</gallery>
The part numbers on the chips seem to be scratched-off (or covered by paint, or is it just old glue from stickers?). The "GI" logo on the large chip implies that it is the popular General Instrument [[SP0256]] speech chip, probably the standard -AL2 version (the ending L2 may be still visible? not sure there - on the photo it vanishes under the pot axis). The clock frequency of the oscillator isn't visible (from the perspective from where the photos were taken).
The GNDed pins somewhat confirm that it is a SP0256 (Pin1=Supply GND, Pin10,11=A8,A9, ie. only 6bit allophone numbers used).