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Copying EPROMS (for backups) of 90s gear?
MUFF WIGGLER Forum Index -> Music Tech DIY  
Author Copying EPROMS (for backups) of 90s gear?
Rex Coil 7
Ok, full disclosure ... my name is Brian and I am an idiot.

Now that we've established that, movin' on.

I have recently procured a few pieces of 90s rack gear (Yamaha, E-MU, Alesis, et al..). There are NO firmware files available on the web for these devices ... anywhere ... at all.

What I want to do (if possible) is to make copies of their installed EPROMs. I would also like to be able to store the firmware file(s) on data storage medium (computer hard drives, thumb drives, and the like). So when I'm done I have a firmware file AND a tangible new EPROM chip loaded with that firmware, all ready to install in the old rack pieces. This just makes good sense to me, especially since you cannot just download firmware from manufacturer's websites on a lot of this stuff (especially from manufacturers that no longer exist, such as E-MU).

I'm big on keeping spare parts and backup files on hand for all of my gear if possible. This is just another effort towards that end.

I've done a little research, so I understand I need to purchase some type of EPROM "burner", which would (I guess) extract or read the firmware on the existing EPROM chip, load it in to my computer ... then place a new EPROM blank into the burner and load the firmware I've copied into my computer into the new blank EPROM chip. Pretty much like doing any other data transfer from one piece of external hardware, into a computer, then transferred into another piece of external hardware. Almost like burning CDs with an external CD drive.

Do I have this correct so far?

So now I need guidance regarding a decent EPROM burner, the required transfer software (for PC, Win10), and blank EMPROMs.

*** What hardware do I need?

*** What software do I need?

*** What makes a "good" EPROM blank and where do I obtain them?

There's a LOT of stuff on eBay for these purposes, but I don't know one from the other.

I'll need to be handheld a bit as this is explained to me. I've never done anything of this nature beyond standard hard drive installations, using hardware SYSEX backup devices (such as the Alesis Datadisk), and so on. In the early 90s, back in the DOS 5.0 and Windows 3.1 286/386/486 days, I knew batch language like I know English ... so that's about the extent of my background and previous experience.

Thanks for your help ... keeping my newly acquired 90s rack gear up and running is important to me.

nodnod
Starspawn
For the old eproms Ive read and burnt With the minipro tl866, it wont help you With newest atmegas, but does all the oldies fine.
Graham Hinton
Rex Coil 7 wrote:

*** What hardware do I need?


There are two main types of "Device Programmer": standalone and PC based. A standalone one would be a better bet given how fast computer interfaces and OSes change. You can probably find a Data I/O system on eBay for peanuts (that cost thousands in the '80s).

The important thing to check is that the programmer has a memory at least as large as the devices you want to use. Also check what devices it will burn, including different manufacturers of the same part. EPROMs of the same size are usually pin compatible when being read, but not necessarily when being programmed.

If you only want to handle '90s era gear with 5V EPROMs most programmers will do, if you want older gear from the '70s the early EPROMs needed +12V and -5V as well and most PC based systems won't do handle that.

Quote:

*** What software do I need?


If it is PC based it will come with its own software, but that may not work on a modern OS. You could use an old computer though.

Standalone programmers usually have an RS 232 interface so you need a serial port on your computer and some "Terminal Emulator" software. If your computer does not have a serial interface, FTDI make some good RS232 to USB cable adapters. The only terminal emulator I recommend for the Mac is Serial from Decisive Tactics, others get confused if you pull a USB cable and plug it in again.

Quote:

*** What makes a "good" EPROM blank and where do I obtain them?


A UV lamp. There are special types with drawers to slide a couple to a lot of EPROMs and give them a zap for 20 minutes. Flash memory has replaced EPROMs so you'll only find these 2nd hand and then it's a matter of if the tube is still good.

There are standard file formats for ROM images, the most common is Intel Hex for up to 64k x8, and others for larger. They are ASCII text so they can be easily viewed and edited.
Synthiq
The TL866 II Plus seems to be the most popular low cost programmer on Amazon and ebay but note that it can only generate VPP voltages up to 18V. Some older EPROMs like 2716 require 25V but you can at least read these memories so you can backup the data to your PC which I assume is most important task right now. Read the instructions to see if it fits your needs. It can be found here:
http://www.xgecu.com/MiniPro/TL866II_Instructions.pdf
Rex Coil 7
Great information, thanks folks!

Graham Hinton wrote:
Rex Coil 7 wrote:

*** What hardware do I need?


.... If you only want to handle '90s era gear with 5V EPROMs most programmers will do, if you want older gear from the '70s the early EPROMs needed +12V and -5V as well and most PC based systems won't do handle that.


Interestingly enough, here's the specs on the PSU for the E-MU rack synth:

(quoting) "Internal auto-ranging power supply (Input-95~220VAC), output +5VDC@2A, +12VDC@1.5A, -12VDC@.3A." (end quote).

I wonder if that shows anything regarding which EPROM voltages were used in these 90s E-MUs?

Graham Hinton wrote:
Rex Coil 7 wrote:

*** What makes a "good" EPROM blank and where do I obtain them?


A UV lamp. There are special types with drawers to slide a couple to a lot of EPROMs and give them a zap for 20 minutes. Flash memory has replaced EPROMs so you'll only find these 2nd hand and then it's a matter of if the tube is still good.
In the absence of an artificial UV light source, how about direct Sunlight? We have some of the brightest Sunlight on the planet here (due to our proximity to the Equator/Sun's angle, pollution-free skies, and arid weather), and this time of year it is especially powerful. I had read that Sunlight, and to lesser degrees florescent lights and camera strobes, may all be able to erase the data on EPROMs. I guess older ones (or re-writable types) even have clear windows which expose the component that is UV sensitive and actually designed for use as an erasure measure. Again, I'm only repeating something I'd read a few times over the past week or so in my research.

Understand that I'm not taking some contrary position or challenging you, I'm just trying to learn here.

cool
Synthiq
Rex Coil 7 wrote:
In the absence of an artificial UV light source, how about direct Sunlight?

An old EPROM datasheet from Intel mentioned that it will be erased in a week if left in the sun.
Rex Coil 7
Synthiq wrote:
Rex Coil 7 wrote:
In the absence of an artificial UV light source, how about direct Sunlight?

An old EPROM datasheet from Intel mentioned that it will be erased in a week if left in the sun.
lol Oh geez! lol so much for that!

Thanks. cool
Rex Coil 7
seriously, i just don't get it

https://www.mouser.com/ProductDetail/Atmel/AT27C512R-70PU/?qs=sGAEpiMZ ZMvKaIdSMCzQp7MEooDLcIygLoEcqk0GBg4%3d

hmmm..... (hides) meh.
Synthiq
Rex Coil 7 wrote:
https://www.mouser.com/ProductDetail/Atmel/AT27C512R-70PU/?qs=sGAEpiMZ ZMvKaIdSMCzQp7MEooDLcIygLoEcqk0GBg4%3d

There is a good chance this 512kbit memory could replace other EPROMs with less capacity as long as they are using a 28-pin DIP package. If you want to replace a 27256 EPROM, address line A15 will be driven by the VPP voltage which should be 5V in normal operation so you will only use the upper half of the 512kbits. But to be safe I would copy the same code to both halves. For a 27128 memory I would likewise copy the 128 kbits four times and so on. Below are the pinouts for Intel EPROMs of different sizes but other manufacturers may deviate from this so check first.



The EPROMs from Mouser you referred to are OTPs (one time programmable) and not erasable as they are plastic packages and don't have window for UV light to erase them.
The Real MC
Make sure the library of PROMs that the burner supports is OEM specific not generic. Not all EPROMs under the same type have the same timing waveforms or programming voltages between manufacturers. Also make sure the library covers different access times IE 27C256-25 versus 27C256-30. Those are gotchas that many people overlook.

Yes you can wipe an EPROM clean by exposing it to sunlight, but the UV spectral intensity of sunlight is far less than a dedicated UV EPROM eraser.
Grumble

Look what I found some time ago...
I could erase one for you, even program it if you have a binary file...
tioJim
Hi

This post has piqued my curiosity ...

Do you expect the EPROMs to fail? Do EPROMs of that era have a history of failing? Not questioning your intentions, just curious.

And, for rack gear of that era, did all the manufacturers use similar EPROMs? Won't you need lots of different programmers and blanks to cover the variety of designs? Again, just curious!

It's a great plan. I wish you luck with it. It's just the sort of slightly unhinged, obssesive thing I'd do! hihi
Rex Coil 7
Grumble wrote:

Look what I found some time ago...
I could erase one for you, even program it if you have a binary file...
Thank you very much for the offer, it's a very kind and generous gesture. But it's not the EPROM that I seek, it's the ability to make the backups that I wish to obtain (the whole sortof "give a man a fish and he eats for a day ... teach a man to fish and he eats for a lifetime" thing).

In any case, I don't have the files needed. I don't even know how I would go about extracting them (which is the whole point of learning how to copy them). Some of these rack synths do not have firmware floating about on the web, either.

Again, thank you for your kind and thoughtful offer.

nodnod
flts
The previously suggested Minipro TL866 reads quite a lot of older EPROMs successfully - the Taiwanese company that manufactures it has a complete list on their site. Even though is unable to burn some of them, as some of the previous commenters say. It's of the "cheap and cheerful" variety but in a good way as well, easy to get hold of - just beware you aren't buying an unauthorized copy - and relatively painless to make backup files for later use.

I'm sure Graham's suggestion of buying an older, more "professional" unit is a good one, would fancy something like that myself as well - if for nothing else, at least for duplicating jobs without a computer. I can't help much with brands or makes there, only have "home lab" experience of the aforementioned newer Taiwanese gadget with USB connection and (pretty horrible but still usable) Windows software.

There are some larger collected synth (E)EPROM repositories that house a lot of useful dumps, the one I look at most often being http://dbwbp.com/index.php/9-misc/37-synth-eprom-dumps ... Might I suggest that whatever you end up with, do share the results with the community if you feel like it? smile
Rex Coil 7
tioJim wrote:
Hi

This post has piqued my curiosity ...

Do you expect the EPROMs to fail? Do EPROMs of that era have a history of failing? Not questioning your intentions, just curious.

And, for rack gear of that era, did all the manufacturers use similar EPROMs? Won't you need lots of different programmers and blanks to cover the variety of designs? Again, just curious!

It's a great plan. I wish you luck with it. It's just the sort of slightly unhinged, obssesive thing I'd do! hihi
1.) Why am I pursuing this? It's not so much that the EPROM itself is prone to failure (well, at least not for about 20+ years or so of total life), it's the firmware that is on the EPROMs that I wish to gain access too. I want to be able to copy it to create backup files, as well as reload that firmware should it ever become corrupted. It's also handy for upgrading an older version to a more recent version. Let's say I locate a swingin' deal on a "Synth X" rack synth, but it has version 1.0 firmware in it. If I have the firmware from a previous purchase/ownership of a "Synth X ver 2.0" on hand I can uprate the one with ver1 to ver2. This is just one situation that may come up. I've actually run into this exact situation more than once. The Line 6 M13 can be purchased rather inexpensively if one is found with the older firmware. You buy it for cheap, then upload the most recent firmware and you're golden. I have actually gone through this 2x already with the M13 now, since I like that FX device and have acquired a total of 3 at this point.

2.) ~yes~ many rack synths of the 90s used different EPROM designs, but once you learn how to go about the process of backing them up, it's then a matter of (possibly) obtaining a few different burners. Sometimes things like that may be acquired without too much expense. Remember, this whole adventure is a learning process for me. At present, I am only concerned with three manufacturers (Yamaha, Alesis, E-MU). I may get lucky and discover they all use the same EPROM configuration. But I'll never know that until I dig into this topic and learn, right? Again, that is the whole point of my research AND this thread.

3.) Blank EPROMS seem to be pretty inexpensive. Many are less than $2.00.

4.) Did all manufacturers use the same EPROMS? I have no friggin clue. However as I stated above, I'll never know until I actively make an attempt to learn.

5.) Do EPROMs fail? According to various sources I've located, they have an expected mean time between failure that spans anywhere from 15 years to 20 years. The 90s were (up to) 28 years ago, this being 2018. It makes sense to me to take the time to at the very least look into the process of making backup copies. Tick tock, these 90s rack synths are getting older by the minute.

SUMMARY: I'm the type that has no problem with collecting repair parts for various pieces of kit that I decide I like. Having owned and operated a warranty/repair center which represented over forty different power equipment manufacturers for fifteen years, I've come to respect the idea of having access to repair parts for valued older gear. EPROMs, as well as ANYTHING that the human hands have access too (which are the single most likely things to fail) such as pots, encoders, buttons, switches, and also things such as displays and internal power supplies make sense to have on hand if I wish to be able to keep some given device that I've decided I really like, operating.

The only guy that needs a spare tire is the one with the flat on the side of the road. Right?

I suppose as I age, my experience with owning a repair center and my military experience and training is kicking in more and more each day. Both experiences literally SHOUT the same doctrine ..... BE PREPARED.

So those are some of the reasons why I am trying to learn what I can about making my own EPROM backups, as well as backing up the instructions they're loaded with.

Also ... Ya never know when you may run across one of those ads on eBay that says "Non working ... Parts Only" for some coveted piece of gear when all it needs is a firmware reload, and it can be had for $25 bucks. Know what I mean? I really adore the Nord Micro Modular. I've seen some sold for less than $50 bucks that were billed as "not working, parts only". I'm the sort that will buy that item just for it's parts, so that I may keep the one(s) I have stocked with repair parts. What's missing? The ability to create a new EPROM. If I learn how to do this, I can use one of my own Nords to extract the firmware from, and then use that to create a new EPROM just to be able to keep mine running, as well as empower me just that much more should I run across the "parts only" swinging deal on one that doesn't work.

It's all about empowerment and independence. After all, isn't that what all of the tools on our toolboxes are for?

thumbs up
Rex Coil 7
flts wrote:
The previously suggested Minipro TL866 reads quite a lot of older EPROMs successfully - the Taiwanese company that manufactures it has a complete list on their site. Even though is unable to burn some of them, as some of the previous commenters say. It's of the "cheap and cheerful" variety but in a good way as well, easy to get hold of - just beware you aren't buying an unauthorized copy - and relatively painless to make backup files for later use.

I'm sure Graham's suggestion of buying an older, more "professional" unit is a good one, would fancy something like that myself as well - if for nothing else, at least for duplicating jobs without a computer. I can't help much with brands or makes there, only have "home lab" experience of the aforementioned newer Taiwanese gadget with USB connection and (pretty horrible but still usable) Windows software.

There are some larger collected synth (E)EPROM repositories that house a lot of useful dumps, the one I look at most often being http://dbwbp.com/index.php/9-misc/37-synth-eprom-dumps ... Might I suggest that whatever you end up with, do share the results with the community if you feel like it? smile
Addressing your last statement there .... that is THE primary reason I began this adventure in the first place. Look here (no worries, it's very short) ...

LINK = https://www.muffwiggler.com/forum/viewtopic.php?t=199920&highlight=

As you read my replies in that very short thread, note that as I looked deeper into helping that soul, I realized that even though I had the device with the firmware version he desired, I had no method of gaining access to it so that I may help him. It was that precise moment that inspired me to begin learning about all of this, which in turn pushed me to start this thread.

So, will I share any files I've managed to extract should I elect to pursue this? Absolutely. It's precisely what motivated me to dive into this topic in the first place.

I like helping the humans.

Hug nodnod Lotsa Love
m.o
I would guess a majority of devices from the 80's up until maybe mid 90's with some sort of standard:ish 8/16 bit computer architecture used the same basic type of PROM/EPROM:s for firmware/data storage.

Usually it's the 27C<number of kilobit>-<access speed> wide DIP format, those are the important numbers (27 = EPROM, eraseable with UV).
As mentioned by others, the different brands can require different writing/burning procedures/voltages etc. by the programmer, but once they're burned the brand (usually) doesn't matter to the device (synth) itself.

Sometimes (at least in later devices) I think it's even possible to use 28XXX memories (electrical eraseable) where there was originally a 27XXX memory used.

Going into the later 90's I would guess smaller quad-pack chips, these require adapters for your programmer and making sure they can be handled.

I have successfully backed up and upgraded an number of devices (quadraverbs, DX7 etc), I used a 'cheap' USB programmer from Batronix (I think they're called).
Graham Hinton
tioJim wrote:
Do you expect the EPROMs to fail? Do EPROMs of that era have a history of failing?


I have never known an EPROM fail apart from ones used in development and being constantly erased, after multiple cycles the rare one would fail to erase completely. I say that as an in past life I worked doing firmware development for a microcomputer company shipping about 250k EPROMs a year, but even that is not a large sample compared to the number of EPROMs made. Yes they can fail like anything else, but they are not especially failure prone.

Quote:

And, for rack gear of that era, did all the manufacturers use similar EPROMs?


Is that a serious question? Of course they didn't!

Quote:

Won't you need lots of different programmers and blanks to cover the variety of designs?


You only need one device programmer that can handle all types of interest, but you will need several different types.
The alternative is to use a largish Flash ROM and a site converter for different devices.

The thing that has not been mentioned is the importance of access time. You can replace with faster, but not slower. It is no use having a backup if it can't put its contents on the data bus in time to be read.

m.o wrote:
I would guess a majority of devices from the 80's up until maybe mid 90's with some sort of standard:ish 8/16 bit computer architecture used the same basic type of PROM/EPROM:s for firmware/data storage.


A decade is a long time in computers. The 80s started with 3 voltage 1kbyte devices and finished with around 1Mbyte, from 24- through 28- to 32-pin packages. There was also a format war between Texas Instruments and Intel as TI were the first to make a single 5V EPROM (2516), but when Intel caught up they used different pins.
gwpt
I use the older model of this programmer and it works well under window 10. Might be overkill but it does heaps of other devices too:

http://www.mcumall.com/comersus/store/comersus_viewItem.asp?idProduct= 4282

And hou can pick up cheap UV erasers for $20 off ebay.

Ive backed up many eproms over the years and to answer your question about whether they use similar ones the answer is, there is a small common range for most bits of gear.
For eighties gear most things use 2732, 2764, 27128 and 27256 (which correspond to 4k, 8k, 16k and 32k of RAM which makes sense and most CPUs of the time could only address 64k and lart of that was used for RAM and special registers etc)
Some gear used smaller (eg 2716), larger and different but it seems to be the minority.

The modern 27Cxx EPROMs all seem to work in old gear which makes life easy. Just be warned, ive bought a few of ebay and quite a few have been duds. They claimed new byt they looked used to me...
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