MHT Speech Synthesizer aka Sintetizador de voz ([[MHT Ingenieros]]) == Technical == It uses a [[SP0256]](-AL2?) chip. * The I/O address is &FBE0. (only A10,A7,A6,A5 and A4 are decoded) * The '''clock frequency is unknown''' (as shown on the photo, it uses an oscillator, ie. NOT the 4MHz signal on the expansion port). Port FBE0h READ: bit 6 Status 1 (0=Speech Busy, 1=Ready/Halted) (SBY Pin, Speech Busy) bit 7,D5-D0 Not used (garbage, probably usually highz)Port FBE0h WRITE: bit7-6 Ignored bit5-0 Allophone number ;data can be send when Status.Bit'''?'''=0 * [[SP0256]]* [[SP0256 Voice Generator]]* [[SP0256 Instruction Set]]* [[SP0256 Allophones]]* [[SP0256 Pin-Outs]] Now, thanks to Jose Leandro, the hardware specialist of the spectrum, with his famous page : http://trastero.speccy.org/cosas/JL/JL.htm We can know more about this hardware. == Pictures == <gallery>caption="MHT Speech"> File:MHT-sintetizdor_de_voz-001.jpg|OutsideFile:MHT-sintetizdor_de_voz-003.jpg|InsideFile:MHT-sintetizdor_de_voz-004.jpg|Component SideFile:MHT-sintetizdor_de_voz-007.jpg|Solder Side
</gallery>
<gallery caption="MHT Speech Synthesizer Layout, thanks to Jose Leandro">
File:MHT Speech Synthesizer - interface_delante.jpg|Top
File:MHT Speech Synthesizer - interface_detras.jpg|Bottom
File:MHT Speech Synthesizer - cara_componentes.jpg|Components
File:MHT Speech Synthesizer - cara_pistas.jpg|Tracks
File:MHT Speech Synthesizer - PCB Front.png|PCB Back
File:MHT Speech Synthesizer - PCB Back.png|PCB Front
File:MHT Speech Synthesizer - PCB Chips.png|PCB Chips
File:MHT Speech Synthesizer - PCB Complete.png|PCB Complete
File:MHT Speech Synthesizer - componentes.png|Components
File:MHT Speech Synthesizer - pistas.png|Tracks
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).
'''Caution''' - There are two files, [[:Image:MHT-sintetizdor_de_voz-005.jpg]] and [[:Image:MHT-sintetizdor_de_voz-008.jpg]] circulated in internet.
Despite of their filesnames, they do NOT show a MHT speech synthesizer - please do not add these files to this page!
The hardware shown on those pics is an [[ARA Video Digitizer]], nothing to do with MHT Speech.
== Software Covertape ==
<gallery caption="Software Covertape">
Image:Software del Sintetizador de Voz (MHT) Front Covertape.jpg|Front Covertape
Image:Software del Sintetizador de Voz (MHT) Back Covertape.jpg|Back Covertape
Image:Software del Sintetizador de Voz (MHT) Tape - Side B.jpg|Tape - Side B
Image:Software del Sintetizador de Voz (MHT) Tape - Side A.jpg|Tape - Side A
</gallery>
== Downloads ==
* [[Media:Software of Sintetizador de voz (MHT Ingenieros).zip|Software of Sintetizador de voz (MHT Ingenieros).zip]] (CDT for Emulators)
* [[Media:MHT Speech Synthesizer (Eagle).zip|MHT Speech Synthesizer (Eagle).zip]] (MHT Speech Synthesizer files for Eagle)
* [[Media:Sp0256-al2-reversed-bit-order.zip|SP0256-AL2 ROM]] ('''caution''' - the bytes in the file are in reversed bit-order, ie. the "Target" values are unreversed, all other opcodes and parameters are reversed)
== Other CPC Speech Synthesizers ==
* [[Amstrad SSA-1 Speech Synthesizer]] ([[SP0256]] based)
* [[Dk'tronics Speech Synthesizer]] ([[SP0256]] based)
* [[TMPI speech synthetizer]] ([[MEA8000]] based)
* [[Software Speech Synthesizers]] (Software based)
== Weblinks ==
* [http://www.cpc-power.com/index.php?page=detail&num=10936 ''MHT Speech Synthesizer'' from CPC-Power]
* [https://cpcrulez.fr/hardware-audio-synthetiseur_vocal-MHT-sintetizdor_de_voz.htm ''MHT Speech Synthesizer'' from CPCrulez]
* [http://hardware.speccy.org/temp/Amstrad-SintetizadorMHT.html ''MHT Speech Synthesizer'' from hardware.speccy.org]
[[Category:Music and sound]] [[Category:Peripherals]]