Sheets - Yamaha Disklavier MX100A Product Handbook

8. Sheets

Hybrid models incorporate a variety of circuit sheets. The table below lists and describes the most important of
these sheets. Note that sheet combinations vary according to the model.
Sheets
The following table lists and describes the different type of sheets that are used in Yamaha hybrid models.
Control Sheet
Includes:
• CPU (Central Processing Unit)
• Either ROM or Flash Memory
PK-CTL Sheet
Includes:
• CPU
• ROM, EEPROM (Electronically
Erasable and Programmable ROM),
or Flash Memory
Sensor Sheet
Includes:
• CPU
• ROM or flash memory
Drive Sheet
• Installed in the controller.
• Includes a CPU, and controls all of the operations of the controller.
• During playback: Transmits MIDI data from the FDD (floppy-disk drive) to the
PK-CTL sheet.
• During recording: Receives performance data (MIDI data) from the PK-CTL
sheet, and sends this data to the FDD.
• For models up through Mark II, the application programs are installed in the
ROM.
• Starting with the MarkIIXG, flash memory is used instead of ROM.
• Flash for song memory: 1MB or 16MB
• Flash memory for program: 4Mbits or 8Mbits. (Programs can be upgraded from
floppy.)
• The name is an abbreviation for "Pedal & Keyboard Control Sheet."
• On upright models, installed on the drive sheet in the lower front board, by the
treble side. On grand pianos, installed in the key-drive cover on the treble side.
On GranTouch models, installed next to the speaker behind the treble side.
• Includes its own CPU, and controls communication among the drive unit, sensor
unit, and control unit.
• During playback: Receives MIDI data from the control sheet, converts it into
solenoid drive data, and transmits the result to the drive sheet.
• During recording: Receives performance data (MIDI data) from the sensors and
transmits this data to the control sheet.
• The program is loaded in the sheet's ROM (or flash memory, if MPX70 or
MarkIII).
• Generates playback tables through self-calibration, and stores the tables in
EEPROM (or flash memory, if MPX70 or MarkIII).
• The MPX70 and MarkIII use flash memory (rather than ROM and EEPROM) to
store the program and playback tables. The program can be upgraded from
floppy.
• The Sensor sheet includes a CPU, and transmits the performance data detected
by the various sensors (key, hammer, and sostenuto-Pedal Sensors) to the PK-
CTL sheet.
• Note that there are a variety of sensor-related sheets: Hammer Sensor sheet, Key
Sensor sheet, hammer emission sheet, key emission sheet, hammer receive
sheet, key receive sheet, etc. The term "Sensor sheet," however, specifically
refers to the Sensor sheet with the CPU.
• In the past the Sensor sheet was typically installed in the Hammer Sensor, but
the recent trend is to install it in the Key Sensor.
• The CPU includes ROM and photoreceptor functions. The program is written on
the ROM (except for the MPX70 and MarkIII).
• The MPX70 and MarkIII use flash memory (rather than ROM) to store the pro-
grams. The program can be upgraded from floppy.
• Installed under the key drive unit.
• During playback this sheet receives data from the PK-CTL sheet, amplifies the
data (transistors), and drives the key solenoids accordingly. It also transmits
pedal-drive data to the pedal drive sheet.
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