The clock signal for the ACIA is '''unknown'''. As said above it is based one the same oscillator as used for the ZN449, however, the oscillator is probably ''whatever'' MHz (?) divided by ''whatever'' (?), and its unknown if the ACIA and ZN449 clocks are using the same divider (ie. the ZN449 samples at 19.444kHz, but the ACIA may, or may not, use another frequency).
The Music Machine uses [[NMI ]] interrupt, but it is not clear exactly what it uses it for.
All of the devices on The Music Machine data bus are accessible to the Amstrad within its I/O space. ACIA transactions must use 16-bit IO instructions; the converters are accesible via 8-bit IO instructions.
Image:Music machine 2.jpg|missing female connector (?)
Image:Music machine back.jpg|Backside
Image:Music machine inside 1.jpg|PCB
Image:Music Machine - inside 1.JPG|Inside 1
Image:Music Machine - inside 2.JPG|Inside 2
Image:Music machine microphone 1.jpg|The microphone
Image:Music machine microphone 2.jpg|The microphone
<gallery caption="The Music Machine Layout, thanks to Jose Leandro">
File:Music Machine - Delante.jpg|The Music Machine - Front
File:Music Machine - Detras.jpg|The Music Machine - Back
File:Music Machine - Conectores.jpg|The Music Machine - Connectors
File:Music Machine - Sin Tapa.jpg|The Music Machine - Without Top
File:Music Machine - PCB Componentes.jpg|The Music Machine - PCB Components
File:Music Machine - PCB Pistas.jpg|The Music Machine - PCB Tracks
File:Music Machine - PCB Front.png|The Music Machine - PCB Front
File:Music Machine - PCB Back.png|The Music Machine - PCB Back
== Datasheets ==
* [[Media:MC1458.pdf|Datasheet for MC1458]] {{EN}} {{PDF}}* [[Media:MC 6850.pdf|Datasheet for MC6850]] {{EN}} {{PDF}}* [[Media:A6850.pdf|Datasheet for ACIA 6850]] ({{EN}} {{PDF}}* [[Media:1983 Ferranti Data Converters.pdf)|Datasheet for Ferranti Data Converters]] {{EN}} {{PDF}}* [[Media:ZN448.pdf|Datasheet for Ferranti ZN448/ZN449]] (pdf){{EN}} {{PDF}}
== Manual ==
* [[Media:Music_Machine_Manual.pdf|Music Machine (RAM Electronics) Manual]] (pdf) {{EN}} {{PDF}}
== Download ==
* [[Media:Music Machine (tape).zip|Music Machine (tapeTape).zip]] (CDT for Emulators & Exemple on MP3)
* [[Media:Music Machine (Eagle).zip|Music Machine (Eagle).zip]] (Music Machine files for Eagle)
== Weblinks ==
* [http://www.cpc-power.com/index.php?page=detail&num=4329 ''Music Machine'' from CPC-Power]
* [http://cpcrulez.fr/hardware-audio-music_machine.htm ''Music Machine'' from CPCrulez]
* [http://hardware.speccy.org/temp/Amstrad-MusicMachine.html ''Music Machine'' from hardware.speccy.org]