Yamaha TX81z – Version 1.6 Firmware EPROM OS Update for FM Synthesizer TX-81z


SKU: FW-283 Category: Tags: , , ,


Yamaha TX81z OS update v 1.6 – Final Revision

This is firmware update 1.6 and is the latest official released operation system by Yamaha in 1988. This operation system update/upgrade requires one eprom chip.

Check current version:

Power device while holding BOTH the [left] and [right] CURSOR buttons

Features/improvements from 1.5 to 1.6:

1 . When a voice number parameter change message is received in Performance Edit mode, if D01 is the voice number received after preset voice number C32, switching is done incorrectly — not to D01, but to 101.

  1. When a POLY/MONO channel mode message is received in Single mode and the basic receive channel is set to OMNI, this does not switch to either POLY or MONO. When set to any channel (1-1 6), no switching is done although the message has been received.
  2. Given a portamento time control change message in Single mode, the portamento time changes every time a channel message is received, regardless of the basic receive channel setting.
  3. When the key assign mode is set to “altr” (alternate) in Performance mode, only channel controller information (MW, BC, FC, VOL, AT, PB) matching that in the basic INST 1 receive channel should have been enabled, but other controller information is also enabled.
  4. When a MIDI parameter change message, which includes data outside the permissable range, is received, the LCD displays an improper message.


  • Fully verified before shipping and professionally packaged in anti-static material.
  • The Yamaha TX81z on the picture is not for sale 🙂
  • You have to perform factory reset after the installation.
  • The IC chip socket is located at IC 15