Author Archives: grantb4

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

Posted in Yamaha DX7 | Leave a comment

Korg Nu:Tekt NTS-1 MIDI In and Out

While waiting on the availability of the Korg Nu:Tekt NTS-1 Custom Panel Rev C, I thought I would play around a bit with MIDI In, Out and Thru for the thing. I might make a board that provides 5-pin DIN … 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

Posted in Yamaha DX7 | 1 Comment

Getting the guts sucked out of my eyeball

Hey kids, I’m having surgery this week.  Soldering and programming to resume as soon as I’m able, but I imagine that’s many weeks away.  Here’s my surgeon doing the same procedure. Eeek. https://www.csurgeries.com/video/pars-plana-vitrectomy-macular-hole/

Posted in Medical Fun | 1 Comment

6809 & 68HC11 Monitors, Assemblers, C Compilers, RTOS … from the 90s

I retrieved some old embedded fun I had in the 90’s off an old disk. More to come at some point once I find the other disk.  Anyway this is a recreation of an old website I had. Retro fun. … Continue reading

Posted in Motorola 6809 68HC11 | 1 Comment

TurboCPU MIDI Board – Alternate Source

If you are in the UK or EU (ouch), here is a source for a DIY MIDI IN/OUT/THRU bare PCB that can be used with the TurboCPU. No DAC option, but otherwise it’s pretty similar to the MTG MIDI board. … Continue reading

Posted in Pro One CPU | Leave a comment

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

Posted in Yamaha DX7 | 1 Comment

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

Posted in Uncategorized, Yamaha DX7 | Leave a comment

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

Posted in Yamaha DX7 | 1 Comment