So why use Modular IV to emulate an old 8-bit computer?  Firstly, in order to recreate the music of that 8-bit computer when it is no longer available, and secondly as a learning exercise to get to grips with some of the basics of Scope Modular patching.

In 1978, Exidy released the Sorcerer Computer and in 1979 I purchased a Mark II model with 16K of RAM and expanded it to 48K.  The Sorcerer came without any on-board sound generating capabilities, but in 1980 I purchased a small DAC board with some four-part notation software.  The soundboard was about the size of a matchbox and generated a sine wave or organ-like tone.  It was four note polyphonic, and the tone was very distinctive due to 8-bit quantization noise that added a sort of raspiness to the basic tone.

The music generated was combined with vocals and guitar, often played in time with a tape recording of other parts, played back at twice speed to give octave higher parts.  Many of the tracks ended up as promo tracks for the local FM radio station, and in 2008 these tracks were combined into an album called 'Sorcerers Apprentice' in honor of my computer mentor 'S' Kenn Stokes.

  1. Modeled from an existing organ patch, the usual components are all here, with the MVC providing control voltage signals from incoming MIDI.

  2. The three oscillators provide a tone similar to a three drawbar organ, with one of the oscillators tuned an octave above the others to give a brighter overall tone.

  3. A 24db low-pass filter provides some low end, as the Sorcerer often provided the bass line for many of the tracks.

  4. Now, most importantly, the bitQuant module is used to simulate the quantization noise of the original Sorcerer soundboard.  After some trial and error, I found that a value of '3' or '4' generated a result closest to the original sound.

  5. Note that the bitQuant is only applied to the third oscillator.  This allows mixing with the first oscillator of the same tuning which can vary the degree that the bitQuant colors the sound.

  6. The phaser is included to reproduce a Boss foot pedal phaser which was used on the original 1980 tracks.  But most of the time it is turned off or can be omitted.


Modular 8 Bit Micro Patch


Dante May 2011


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