Author Archives: grantb4

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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New MTG Kawai R-50/R-50e to R50iii conversion kit

This is a kit loosely based on the R50iii that was a factory modified/upgraded R50 or R50e.  The factory had the advantage of starting with new blank circuit boards which current R50 owners do not.  Still, this expansion is pretty … Continue reading

Posted in Kawai R100 | Tagged , , , , , , , | 1 Comment

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

Posted in Yamaha DX7 | Tagged , | 12 Comments

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

Posted in Uncategorized, Yamaha DX7 | Tagged , , , | 1 Comment

Kawai R100 QuadROM (x4) Board

It’s important to have a bunch of unfinished projects on the go 😉 so here is one more on my list. If you recall, I sell a PCB for the Kawaii R100 that has three EPROMs on it. This gives … Continue reading

Posted in Kawai R100 | Tagged , , , , | 3 Comments

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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Yamaha DX7 SuperMAX Redux

Something else I’m working on… The new circuit boards just arrived and the testing so far is good. The boards are a slight improvement over the original: I’ve increased the size to allow for a screw to hold the board … Continue reading

Posted in Yamaha DX7 | 11 Comments

Vintage Synth CPU Updates, Upgrades and Expansions

There are so many CPU upgrades now for our beloved synths of old, that I thought it would be nice to have a catalog of them all in one place. If someone else has done this already, please let me … Continue reading

Posted in Pro One CPU, Uncategorized, Yamaha DX7 | 4 Comments

TurboCPU v1.40 (beta) is available

A new version of the TurboCPU+MIDI firmware has been uploaded to the website, along with a new version of the Windows application TurboCPU.exe. Added: “MIDI Note Priority” which supports 4 modes: Lowest Note, Highest Note, Last Note and my original … Continue reading

Posted in Pro One CPU | 1 Comment

MIDI Patch Change Editor v3.31

Ok folks, I have uploaded v3.31 of the PC editor for the MIDI Patch Changer. There are several bugfixes regarding Preset Navigation and the MIDI Events Editor. As well, by popular demand, a “Cancel” button has been added to the … Continue reading

Posted in MIDI Patch Changer | 2 Comments