Category Archives: Yamaha DX7

Heads Up: DX7 SuperMAX+ v3 (1024 patches) on the drawing board

During the COVID I had a bit of time to do what no one wanted to do. Write an emulator for the DX7 microcontroller. That is, EVERYTHING BUT the sound generation.  There are lots of virtual DX7’s out there but … Continue reading

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Yamaha DX7 Backlit LCD and OLED Current Draw

Received a good question from Andy P. today, asking about the current draw for the OLEDs keeping in mind the DX7 has a very old power supply.** Here are some numbers I came up with for a limited, but representative, … Continue reading

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Found Another DX7 Bug

This one isn’t a huge bug, but anyone with an original DX7 running OS version 1.7 or earlier (on an expander based on it) can see this bug.  If you edit a patch and set an oscillator mode for Fixed … Continue reading

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MIDI Velocity Tester

While looking into the DX7 and some of the expansions for it, I needed a way to capture all the possible velocities that a given MIDI keyboard could put out. Not all of them send all 127 possible velocities. I … Continue reading

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DX7 Velocity Issues

A lot of comments, cliche’s, criticisms and chit-chat exists about the original DX7 Velocity limitations.  I will address a few of those, mainly from the perspective of someone looking at the underlying code. It’s another level of fun for someone … Continue reading

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Yamaha DX7 OS without Active Sensing

While peeking around at the various DX7 firmware versions I was able to identify the code that is responsible for the DX7 transmitting $FE (MIDI Active Sensing) constantly.  I did not have the time to look at adding a menu … Continue reading

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Hitachi HD6303 Monitor

The Hitachi 6303 is a variation on the Motorola MC6800/6801/6803 Motorola microprocessors and microcontrollers from the late 70’s and early 80’s.  I have an interest in reverse engineering embedded systems from that era.  Previously I have created a 6809 EPROM … Continue reading

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A DX7 Expansion “for the rest of us”

The DX7 E! expansion is known for being very hard to use. The SuperMAX+ is easier, but still there are so many features that it can be hard to remember them all, … and not everyone needs them.  So I’m … Continue reading

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CR2032 Battery Holder PCB Saver Adapter (for DX7, etc)

Here is a quick “freebie” of sorts. I’ve had this PCB for a while and used them now and then to fix dead 3v coin cell batteries on Yamaha DX7’s and other synth’s and drum machines. You can order the … Continue reading

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Yamaha DX7 ROM Cartridge BINs

I needed to get the BIN data from some DX7 cartridges, but I don’t have them all. I only have ROM3. So I desoldered the EPROM in the ROM 3 and compared that to the .SYX files found easily on … Continue reading

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