Memory; Scanning; Synthesis Asic - Kurzweil CUP2 Service Manual

Memory

The CPU memory is located along the right side of page 1. As previously described, the CPU
initially boots from Boot Flash, U4. This is non-volatile memory that is programmed once at the
factory. However, if a special Boot EPROM Module is plugged onto J1, then the CPU will boot
from it instead. When Engine Boards are manufactured, the factory uses this module to load
U4. If the data in U4 becomes corrupted and the CPU cannot boot, the EPROM module can be
used to reload U4.
U3 is a NAND Flash chip, which is very similar to what is used in memory cards and USB
“"thumb”" drives. It holds the operating system code, sound programs and setups, and user data
(user sound programs and MIDI sequences). The capacity is 64MB.
U2 is system RAM. After bootup, the operating software executes from system RAM. It also
holds currently used sound programs and MIDI sequences.

Scanning

Software in the operating system also performs scanning of the player controls (keyboard and
pedals) and the user interface (U1) controls (buttons, LEDs, knobs). This is accomplished
through a simple, Kurzweil standardized, interface called ScanPort (J7, page 3, zone D1). Most
of the circuits for scanning are actually on the Interface PCB; only a couple of buffers (U6, U8),
an analog amplier (U9), and decoding logic (U11) are on the Engine PCB. See the Interface
PCB description for more details about ScanPort operation.

Synthesis ASIC

Page 2 has the MARA synthesis ASIC, U5. This proprietary, Kurzweil designed VLSI chip
integrates the following synthesizer circuits:
•• 64 sample playback channels, each with independent playback rate
•• 64 amplitude envelope blocks
•• 256 DSP processors, each with independent envelope
•• Effects processor with 16 processing blocks
•• Patching array for interconnecting the above resources
•• Digital audio formatting circuits
The instrument sound samples are stored in Sound ROM (page 4, zone 5D). The standard
CUP2 has 64MB (only U13 installed) of Sound ROM. Other products using the same Engine
PCB may have additional Sound ROM installed at U14.
The effects processor also uses an external Delay RAM (U12, page 3, zone A4). Pops, audible
crashing sounds, and other extraneous noises are often caused by defective Delay RAM or
connections to it.
Printed Circuit Boards
Engine PCB
2- 3