Backing Up Synth And Sampler EPROM's
(A Quick-Start Guide)

ANIMATED_STAR I want to send special thanks out to Guy Wilkinson ( and Fred Vecoven ( for all the high‑tech info they have supplied to help me learn about this process. I could not have done it without their expert input!

If you are already an expert at burning EPROM's, the webpage you want with some synth and sampler firmware files for downloading is at this link. If you're a newbie... read on

The EPROM's in my synths and samplers will eventually lose their electron charge and die rendering my classic gear useless. This is why backing up those EPROM's is so important. Most of my synths and samplers are more than 30+ years old and still going strong. However, as more years pass by, I'm starting to get worried about losing some of them

I was hesitant about backing up and burning my own EPROM's because it sounded a little overwhelming. Something best left for an expert. I was very surprised to discover how easy it is to make duplicate EPROM's. I ended up buying an EPROM reader/burner and a tube of ten blank EPROM IC's all for less than $55 (USD). One of the least expensive insurance policies I've ever purchased ANIMATED_SMILE FACE

EPROM's were designed to have a 10 to 20 year lifespan, minimum. We have already passed the 20 year mark... Of course, we all know that many have lasted well beyond that range... thankfully! Some synths are not so fortunate. A lot of D‑50 synths are starting to drop like flies. My guess would be that Roland used sub‑par EPROM's during production

Each bit in an EPROM works by holding charge in an "electron well". Over time, the electrons will leak out... it takes between 20 and 40 years on average... The circuit that reads the "wells" takes more time to get a decent result as the electrons deplete. Only programming can refill these "wells". Other problems contributing to electron loss are extreme heat, humid climates and oxidation of the substrate traces. Humidity can get inside and accelerate trace corrosion. If you are the 2nd or 3rd owner of a synth or sampler, you really don't know the history of where it's been. I bought a used JV‑880 and upon opening it discovered all of the black adhesive pads holding the PCB in place had melted and collected into a pool of black goo at the bottom of the case. A hot storage locker in Phoenix? An attic in Baton Rouge, perhaps?

An added benefit of getting an EPROM reader/burner is that if you have access to a more recent EPROM binary file for your synth or sampler, you can upgrade your system to a more current firmware. The following is my version of a Quick‑Start guide for anyone who wants to take the plunge and burn their own


Finding original synthesizer or sampler factory replacement EPROM's or *.BIN files can sometimes prove to be Mission: Impossible so play it safe! Before you start, it's important to note that if you are not careful, it's quite easy to turn your synth or sampler into a brick. Make sure you handle the EPROM's with care. Wear a static wrist band while working on a static free workbench or environment. Also, if you accidentally plug it in backwards or write an EPROM when you meant to read it ... kiss it goodbye

The EPROM reader/burner model I bought is a Minipro TL866CS manufactured by XG Autoelectric. These are available from a zillion different sellers on eBay. I paid $38 (USD) for one at eBay. Shipping was quick, it was packaged securely in a box inside bubble wrap and it also included a USB cable. It gets its +5V power from the USB cable so no external power supply is needed. This basic TL866CS system will read and burn standard EPROM's with 40 pins or less. All of the EPROM's on my synths and samplers have 28 or 32 pins so this basic model is all I need. You will also need to buy some blank EPROM's. To keep the costs down, I chose to use OTP (One‑Time Programmable) EPROM's. I can't recommend what kind of blank EPROM's for you to buy because you need to choose similar EPROM part numbers shown on the face of your synth or sampler EPROM. A short list of some synth and sampler EPROM part numbers is here. Recommended vendors for blank OTP EPROM's are Mouser (USA) and Farnell (Europe). You won't need to purchase any add‑on parts kits or adapters for the TL866CS, unless of course you plan to do more advanced work with unusual EPROM's (square, more than 40-pins, etc...) If you plan to use the more expensive erasable EPROM's with clear quartz windows you will want to invest in a UV eraser. Since I'm just using OTP EPROM's, no eraser was needed

The software used to operate the TL866CS is called Minipro. It's free and you can find the current version for Windows at the TL866 Application Software Download link available from XG Autoelectric. There is also a Mac Version and a Linux Version of the Minipro utility but don't ask me how to install it. I tried to install the Mac version but was unsuccessful so I gave up and installed the Windows version instead

TOP: EPROM With Label Removed Exposing The Clear Quartz Window
Left: D-110 EPROM IC #19                     Right: Blank OTP EPROM
You should update the firmware on the TL866CS after installing the Minipro software. Updating the firmware also installs the current list of compatible EPROM's the TL866CS can read and burn. The TL866CS firmware update is automatic if you are connected to the Internet when you install the Minipro software

To read an EPROM from one of your synths or samplers, you will first need to determine what type of EPROM it is. The EPROM will have a part number silk‑screened onto its face and looks similar to the section highlighted in red as shown in the image to the right. The EPROM on the left was pulled from a Roland D‑110. The EPROM on the right is a blank OTP EPROM replacement. The EPROM on the top is what most of the synth and sampler EPROM's look like with their label removed. In some cases, you will need to remove this label temporarily to read the EPROM part number underneath. Be sure to put the label back in place when finished. It's there to prevent accidental erasure from sunlight, fluorescent, and other UV light sources. Note: Even though the OTP EPROM on the right does not have a clear quartz window, it serves as a good replacement at a reduced cost

The key to using the Minipro software is being able to select the correct EPROM part number. There are a zillion choices. Your best tool for finding the correct EPROM part number is by using the SEARCH feature. Clicking on the SELECT IC button opens up a search dialog window. There is also a button on the main Minipro screen called INFORMATION. Clicking this will call a pop‑up window which will show the correct EPROM notch orientation and how to plug your specific EPROM correctly into the TL866CS. An orientation image is also indented on top of the burner but it's somewhat hard to read. After working with the program a few times, you probably won't need to use the INFORMATION button anymore and you can call yourself an expert!

Once your EPROM is seated correctly and the notch is facing the correct direction, push the lever down to lock it in place. Select the correct EPROM part number and from the drop‑down menu choose DEVICE and then READ. Check the display on the right‑hand side of the screen and make sure you have actually captured some EPROM data. Use the drop‑down menu and SAVE it as a *.BIN file. Push the lever to the upright position and remove the EPROM. Done!

You can now take this new *.BIN file and keep it as an EPROM backup on your hard drive. At this point you have two options:
  • Let sleeping dogs lie. Simply keep this *.BIN file available on your hard drive as a backup and use it in the event your EPROM fails someday

    • ~ or ~
  • Burn a new EPROM now to replace your old EPROM

I chose to burn new EPROM's now and replace all of my old EPROM's. Why? Because the synth and sampler cases were already opened up. Might as well!

Get a blank OTP EPROM compatible with the same part number as the one you just read. Place it in the TL866CS, make sure the notch is facing the correct direction and check that all the pins are seated correctly. Push the lever down to lock it in place. Select the correct EPROM part number you are going to burn. From the drop‑down menu, choose File and then Open and select the *.BIN file for your synth or sampler. Next, from the drop‑down menu choose DEVICE and then PROGRAM. Done!

If your goal is to upgrade a synth or sampler EPROM to a more current firmware version, it's as simple as loading a valid *.BIN file into Minipro then choose DEVICE and then PROGRAM from the drop‑down menu. The tricky part is finding a valid *.BIN file for your synth or sampler. I've posted all of my synth and sampler firmware *.BIN files at this link

  • It's important to note that even though OTP EPROM's don't have a clear quartz window, these IC's are also susceptible to electron loss over time and will eventually fail someday. The good news is that once you read, burn and install your new EPROM's, you can rest easy for another 20+ years

  • I wasn't able to backup all of my synths and sampler EPROM's. My U‑20, U‑110 and S‑550 have their EPROM's soldered directly onto the circuit board as a cost cutting measure. Thanks Roland :^(  Some synths, such as my U‑20, have MASK ROM's installed, not EPROM's

  • Plugging an EPROM backwards into a synth, sampler or reader will usually erase the EPROM when you power on the device. Double check that you have it inserted with the notch facing the correct direction

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(FYI - I do not sell EPROM's)

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S-50 / S-550 ZONE

S-50 / S-550 ZONE

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