Chapter 2 Printed Circuit Boards; Function Overview; Engine Pcb Function Summary; General - Kurzweil sp5-8 Service Manual

Chapter 2
Printed Circuit Boards

Function Overview

The SP5-8 contains three main printed circuit boards (PCB): the Engine PCB, the Right Front
Panel PCB, and the Left Front Panel PCB.
To greatly generalize:
The Engine PCB contains everything concerning sample playback, audio effects, and the
functions of the SP5-8's operating system.
The Right and Left Front Panel PCBs help the Engine PCB communicate with the SP5-8's
buttons, LEDs, sliders, Spin knob, Pitch and Mod wheels, pedals, keyboard, and rear panel
connectors. They also contain the power supply and audio amplifier circuits.

Engine PCB Function Summary

The SP5-8's Engine PCB performs the following functions:
1. CPU for the entire system
2. Synthesis and effects for all of the sounds
3. Sample ROM
4. D-to-A converter for the synthesizer
5. Non-volatile storage of all user data
6. Scanner for front panel buttons, LEDs, sliders, Spin knob, and the keyboard
7. USB controller
8. MIDI interface, both 5-pin and USB
The following function summary descriptions reference the PC3LE Engine PCB, Rev F Ver 1,
schematic circuit drawings (Chapter 7, pages 7-3 through 7-7).

General

The Engine PCB contains the system CPU (a 200MHZ Renesas SH2A integrated
microcontroller), sound synthesis ASIC (Kurzweil MARA), and player control/user interface
scanning. The following paragraphs give a brief summary of these major functions and
associated functional blocks.
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