Music Machine

The Ram Music Machine

A digitally sound sampling and playback device. The Music Machine was built by a British Company called Ram Electronics.

The Amstrad CPC version was almost identical to the the ZX Spectrum version, only difference was the address decoding logic.

Technical Specifications

Information from the manual:

The Music Machine incoporates two Ferranti devices for digital-to-analogue (DAC) and analogue-tod-digital (A to D) conversion. The part numbers are ZN429E8 and ZN449 respectively. The circuit also include a Motorola 6850 ACIA (Asynchronous Communications Interface Adapter) for handling the MIDI channel, two anti-alias filters (one for input and one for output), a discrete microphone amplifier and a headphone amplifier. The clock signal for the ACIA and the ZN449 is provided by a ceramic oscillator.

The incomming signalo from the microphone amplifier is sampled to an 8-bit resolution at a rate of 19.444 thoudsand samples per second. This yields an analogue bandwidth of approximately 9.5KHz which is in fact the cutoff frequency of the filters.

All of the devices on The Music Machine data bus are accessible to the Amstrad within its IO space. ACIA transactions must use 16-bit IO instructions; the converters are accesible via 8-bit IO instructions.