CONTENTS

• 1. SPECIFICATIONS
• 2. STRUCTURAL DIAGRAM
• 3. BLOCK DIAGRAM
• 4. CIRCUIT DIAGRAM
• 5. PC BOARD
• 6. CIRCUIT DESCRIPTIONS
• 7. TROUBLESHOOTING TABLE
• 8. CHECK AND ADJUSTMENT PROCEDURE
• 9. REFERENCE DATA
• 10. PARTS LIST

KEIO ELECTRONIC LABORATORY CORPORATION TOKYO/JAPAN

2. STRUCTURAL DIAGRAM

Diagram showing the physical layout and components of the POLY-800. It includes labels for parts such as the serial number seal, screws (A, B, C) with their respective part numbers and remarks.

3. BLOCK DIAGRAM

A block diagram illustrating the internal architecture of the POLY-800. Key components include the CPU (8085), ROM, RAM, ACIA, D/A, A/D converters, Tape Interface, Keyboard Matrix, Noise Generator, Chorus, and output stages (LINE OUT, PHONE OUT).

4. CIRCUIT DIAGRAM

Detailed circuit diagrams for various sections of the POLY-800, including CPU clock, power amplifier, tape interface, MIDI interface, and more. These diagrams show the interconnections of various electronic components.

5. PC BOARD

Layouts of the Printed Circuit Boards (PCBs) used in the POLY-800, such as KLM-596, KLM-598, KLM-597, and KLM-599. These diagrams show the placement of components and their connections on each board.

6. CIRCUIT DESCRIPTIONS

Introduction

The POLY-800 is an eight-voice, programmable polyphonic synthesizer designed for portability, weighing under 10 lbs with batteries. It features 64 programs, Edit and Tape Interface, MIDI capabilities, a built-in Noise Generator, Chorus, and an all-digital programming system called the "DAC" (Digital Access Control) System.

KEYBOARD DATA PROCESSING AND PANEL SWITCH OPERATION

The keyboard data is processed via a matrix circuit and input to the CPU. Pitch data is output to the Tone Generator. Switch operations are similarly handled. The unit uses static RAM (IC21) for storing user-created sounds, requiring a battery backup to maintain program data when powered off. A charged capacitor provides temporary memory backup.

ABOUT MIDI

MIDI (Musical Instrument Digital Interface) is a standard for interconnecting synthesizers, sequencers, computers, and rhythm machines. The POLY-800 supports MIDI for transmitting and receiving data, including key data, joystick movements, and program changes.

MIDI Data Format: MIDI data is transmitted in messages. Key data consists of 3 bytes: status, pitch, and velocity. Velocity on the POLY-800 is either 0 or 64.

Joystick

The joystick controls pitch bend and modulation. Its sensitivity is determined by the receiving unit. Center values are 00H for the X-axis (bend) and 40H.

Sequencer Clock & start/stop control

Synchronization is achieved using 24 clock pulses per quarter note.

Program change

Program changes consist of 1 status byte and 1 data byte, allowing selection from 64 possible programs.

7. TROUBLESHOOTING TABLE

A flowchart to help diagnose malfunctions by following the signal path in the POLY-800. It guides users through checking battery voltage, loading data, power supply voltages, tone generator output, waveform synthesizer circuits, and data bus integrity.

8. CHECK AND ADJUSTMENT PROCEDURE

This section provides procedures for checking and adjusting various parameters of the POLY-800, including power supply, D/A converter, noise level, master oscillator, cutoff, and resonance. It specifies test programs and required equipment like a DVM and oscilloscope.

Caution: Adjust only the VRs required for servicing, as the product is factory-adjusted.

9. REFERENCE DATA

80C85A SINGLE CHIP 8-BIT CMOS MICROPROCESSORS

Details the specifications of the 80C85A microprocessor, including its power supply, compatibility, instruction cycle, clock generator, system controller, interrupt inputs, serial I/O, and addressing capability.

Block Diagram: Illustrates the internal architecture of the 80C85A.

Pin Configuration: Details the function of each pin on the 80C85A.

10. PARTS LIST

A comprehensive list of components used in the POLY-800, categorized by type (e.g., Carbon Resistors, Metal Film Resistors, Ceramic Capacitors, Electrolytic Capacitors, Transistors, Diodes, ICs). Each entry includes part code, specifications, P.C. board, identification number, function, and quantity.