Yamaha DX5 EPROM V6

From Version 5.0 to Version 6.0
Rom version 5.0 (IN012350/012450) has been updated to version 6.0 (XA94001) to salve the problem below and to change and add parts of the test program.
• With the key assign mode set to split, the source select of either the A or B channel is "0", while the source select of the other channel is not set to 0 (1 to 16); and with OMNI set to OFF, when keys on the DX5 are depressed, there should be sound only from the channel whose source select is set to 0. However, there may be sound from both channels. This has been corrected.
The following are changes and addition of parts of the test program
• The data load test (from the cartridge) has been added before Test # 1 (unbalanced output).
• Test program interruption (added)
To ger out of the test program, it was previously required to tum off the power, or to press the YES button after Test # 15.
This has been improved so that the test program can be interrupted at any time by pressing the YES button while voice memory button A-8 is pressed. When this is executed, the MIDI status will be initialized.
• For test # 1, Step 5 (check attenuate level), the output level has been changed from -21dBm to -17dBm.
• Test # 1, Step 14 (check noise level) has been added.
The noise level should be -75dBm or below for unbalanced output terminais A,B, and P.
• Test # 2, Step 4 (check noise level) has been added.
The noise level should be -75dBm or below for balanced output terminais A,B, and P.
• Test # 6 (initial touch response) has been improved so that when all keys are okay, "All key OK!" will be displayed.
• For test # 12 (OPS test), the operators for both A and B channels were checked at the same time. This has been changed so that the operator can be separately checked for its respective A or B channel. (e.g. for Step 1A, operator-1 for the channel A).
• For Test # 12, Step 8 (feedback max.) as well, channels A and B can now be separately checked.
When the ROM version was updated from 5.0 to 6.0, the two previously used 128K-bit EPROMs were replaced by a single 256K-bit EPROM.
When installing updated ROM (256K-bit EPROM) in units (s/# 2474 and below) which use two 128K-bit EPROMs, remove the two ROM ICs (IC12 and IC13) from MPII board. Then install the updated ROM in the IC12’s place. Nothing is to be installed in the IC13’s place. Reposition two jumper wires to their respective installation holes.
The serial numbers for units using ROM version 5.0 are 1322 – 2474.
This modification has been implemented on products with the serial numbers 2475 and up.
If you have any of above problems, please change to the most recently update ROM (part # XA940001, Ver. 6.0).