Need some EEPROM burning advice

[Midphase]

I recently got me an AVRISP mkII with a ZIF socket attachment and was interested in burning some EEPROMS to update the firmware on some of my vintage synths.

I got AVRDude working, and I started playing around with this GUI front end which seems pretty straightforward. Nonetheless, before I ruin some EEPROMS, I thought I'd check in to see if anyone has any advice on how to go about it.

For one, I'm not sure if I need to worry about the specific settings. I also noticed that while most of the firmware files are in .bin format, while the AVRDude GUI seem to want .eep files. Not sure if I need to worry about trying to convert the .bin files or if it's not necessary.

Here is a link to the AVRDude GUI app that I was thinking about using:

https://blog.zakkemble.net/avrdudess-a-gui-for-avrdude/

[Ian.M]

AVRDUDE (with or without any GUI) is the wrong tool for the job.  It doesn't support *ANY* serial EEPROMs.  You can check its device support list at  https://avrdudes.github.io/avrdude/7.3/avrdude_4.html#Option-Descriptions (see: -p partno).

I am not aware of any serial EEPROM programming software for the AVRISP mkII.  Its for Atmel AVR MCUs and not much else!

[ArdWar]

What kind of EEPROM are we talking about here? The only EEPROM an AVRISP can program (officially) is the one embedded inside an AVR MCU.

burning some EEPROMS to update the firmware on some of my vintage synths.

Uh oh, backup your current firmware before messing with them. I've seen too many tragedies. Better yet if it's socketed or if you can desolder it just keep the current EEPROM somewhere safe and use a blank new EEPROM for the update.

[Midphase]

Interesting...this is what I have:

https://www.amazon.com/dp/B08WL96RD4?psc=1&ref=ppx_yo2ov_dt_b_product_details

I read that it could program EEPROM's and I assumed that it was capable of standalone EEPROMS like the ones used for vintage synth firmware. Did I misread and misunderstand what the EEPROM that they were referring to was only the one built into a microcontroller and not a standalone one like, say something like this?

https://www.mouser.com/ProductDetail/556-AT27C512R-45PU


Should have I gotten something like this instead?

https://www.amazon.com/dp/B0B592HZ1K/?coliid=I2COPGCA0VMH3H&colid=6QC7U6MBJ09D&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

[Ian.M]

Yes, you misunderstood. That claim:

1. Supports all AVR devices with ISP or PDI interface, XMEGAs and certain 51 devices.
2. Programs both Flash and EEPROM

is subordinate to the claim above it which says it supports AVR MCUs, and some of Atmel's old 8051 equivalent MCUs.   As ArdWar explained, it only supports programming the FLASH and EEPROM memory banks of various MCUs, not memory chips.

The AT27C512R-45PU is a parallel OTP EPROM with 16 address pins, 8 bidirectional data pins + two control pins. That's the same technology as UV EPROMs, but in a plastic package with no window so can't be UV erased.  Its not like an EEPROM (Electrically Erasable PROM) and not a serial EEPROM, which typically come in much lower pin count packages.

There's not a hope in hell that an AVRISP II can handle programming that, even with custom firmware and programming software, as the AVRISP II hardware is designed to handle Atmel's serial ISP, PDI, and TPI programming interfaces and simply doesn't have enough I/Os (or even the correct voltages) for parallel EPROMs.

Your second link is to a 'universal' programmer capable of many parallel and serial non-volatile memories including EPROMs, EEPROMs and FLASH, and also some MCUs.  Its much more likely to be what you need.  However you need to go to the manufacturer's website and check the device support list carefully against the chips you actually need to read and program, as there are often older more obscure devices some  'universal' programmers cant handle.

[pcprogrammer]

There is a misunderstanding of the terms here.

EEPROM refers to electrically erasable programmable read only memory and usually has not that much memory. Also for as far as I know only used for some parameter storage in vintage synthesizers, and at that not even in the really vintage ones.

EPROM stands for erasable programmable read only memory and refers to, amongst others, the old 27xxx range of IC's that have these nice glass windows to allow erasing with UV light. These are commonly used in the old synths.

Parameter or patch storage was mostly done with battery backup of the RAM making it non volatile.

Later on FLASH devices came along and where used to store firmware.

So it depends very much on the synth you are looking into.

And like Ian.m wrote the AT27C512R-45PU is OTP, which means you can only program it once.

Be aware that The other programmer you linked to, is not capable of programming 27Cxxx series that need 25V for programming the device.

Support high-voltage chips, such as 27Cxxx series, VPP Maximum up to 25V, that is what TL866II cannot achieve.

Edit: I read it wrong, it seems to be capable of doing it because it refers to the TL866II not being able to achieve the 25V.

Do make sure that the devices you need to program work with the 25V this programmer can provide. Older types might need 28V.

Edit2: Here is some background info to be found. https://cpushack.com/EPROM.html

[wraper]

^Only early EPROM need 25V, certainly not CMOS versions like 27Cxxx which generally need ~12V.

[pcprogrammer]

^Only early EPROM need 25V, certainly not CMOS versions like 27Cxxx which generally need ~12V.

And that is why I wrote that it depends on the synth being looked into.

Vintage synthesizers from 1980 - 1990 have older eproms that need the higher voltage to be programmed. Newer versions might fit in, but when one wants to reuse the old stuff the programmer needs to be capable.

My SIEL Opera 6 uses these old types, my Yamaha DX7IIFD also uses these old types.

Still have a programmer from that era and a bunch of these old EPROMS plus an eraser, but no idea if they are still working. Last used maybe 30 years ago.

Edit: to be sure about what is needed always check the datasheet of the chip before using it in the programmer you have.

[CaptDon]

O.P. stated his synth was currently using a 27C512R so that puts him in the 12 volt world of EPROM's and it the synth and programmer can handle it then also would allow programming of EEPROM's like the 28C256 which is a 5 volt VPP device. 27C128, 27C256 and 27C512 are 12 volt devices. The 27C64 came in 2 flavors, 21 volt and 12 volt. The much older 2716 and 2732 could be 25 volt or 21 volt but it would appear the O.P.'s synth is too new to use those old devices. I have seen some older Lowery and other stand alone console organs that had a 24 / 28 pin ZIF socket on the left hand side which could accept ROM's, PROM's and EPROM's containing additional voices, patches and sequences which were available for sale at the music stores. Some of the old electronic drum pads also had ZIF sockets to change the voice of the drum pad. They were around in the 2716 / 2732 days.

[pcprogrammer]

O.P. stated his synth was currently using a 27C512R so that puts him in the 12 volt world of EPROM's and it the synth and programmer can handle it then also would allow programming of EEPROM's like the 28C256 which is a 5 volt VPP device. 27C128, 27C256 and 27C512 are 12 volt devices. The 27C64 came in 2 flavors, 21 volt and 12 volt. The much older 2716 and 2732 could be 25 volt or 21 volt but it would appear the O.P.'s synth is too new to use those old devices. I have seen some older Lowery and other stand alone console organs that had a 24 / 28 pin ZIF socket on the left hand side which could accept ROM's, PROM's and EPROM's containing additional voices, patches and sequences which were available for sale at the music stores. Some of the old electronic drum pads also had ZIF sockets to change the voice of the drum pad. They were around in the 2716 / 2732 days.

OP did not state that his vintage synth is using that one per se. He just linked to is as an example of what he expected to be able to program with the programmer he bought.

But there are many flavors of EPROM, EEPROM and FLASH to be found. On your programmer you had to select the one that you were using and it would then set the correct parameters to be able to program it.

I made a programmer for my TRS-80, I had at the time that I was in school, as a school project and from that I remembered the 28V being needed for some of them. Long time ago though.

[Midphase]

Howdy,

Ok, so let me fill in some info. First of all, I wasn't thinking of erasing and rewriting the existing EPROMS, but rather create new ones so that in case the new firmware doesn't work, I can always go back to the old one...just in case.

So it does look like I misunderstood the description of the AVRISP mkII device unfortunately...I thought I was being clever since I also needed something that could write to the ATmega644p and I figured I could kill two birds with one stone, but apparently I should have gone for the more expensive Xegu T48 instead (which I also believe can handle the Atmega644p). No worries...thankfully Amazon has a pretty good return policy.

So, the vintage synths in question are the Oberheim Matrix-1000 and Oberheim Matrix-6. I had already purchased new updated firmware EEPROMs for both of these machines on eBay, but since I do have multiple modules that also would need updated firmware, I figured I'd try to learn how to do it myself in the future.

Here are the photos of the two EEPROMS (with the updated firmware) that I bough on eBay, so what I did is check the part number and basically order the same exact thing from Mouser (I didn't realize these were OTW EEPROMs...surprising considering that they were kinda pricey).

So is it safe for me to go ahead and pick up the Xegu T48?

[pcprogrammer]

Here is the list with supported devices, and several 27C512's are on it so it should do the trick.

Nice synths. A studio I worked at long ago had the Oberheim Matrix expander. Very interesting synth to play with. Nowadays quite expensive to get one.

[Midphase]

Oh yeah, the Oberheim Xpander (or the Matrix-12) is on my wish list. They are way too expensive at the moment, but I keep hoping that sooner or later I'll find one that needs some serious TLC for a more affordable price!

Thank you.

[xvr]

W27C512 is electrically erasable EPROM (not an OTP).
M27C512 could be OTP (if no UV window under the sticker), but it could be UV erasable - they have the same part number  Check what kind of 27C512 you bought. If it was expensive it could be UV erasable.

[Midphase]

Definitely no UV window under the sticker. I bought exactly this one from Mouser:

https://www.mouser.com/ProductDetail/556-AT27C512R-45PU

[xvr]

Yes, they are OTP.

BTW, I know success story of erasing of OTP chips in X-Ray machine (in hospital) 

[wraper]

W27C512 is electrically erasable EPROM (not an OTP).
M27C512 could be OTP (if no UV window under the sticker), but it could be UV erasable - they have the same part number Check what kind of 27C512 you bought. If it was expensive it could be UV erasable.

They don't have the same part number, what do you think suffixes are for?

[xvr]

I saw some with the same part numbers (with window and without). But it was a long time ago (more than 30 years ago). So it is possible. I rather surprised that they still available to purchase at all

[wraper]

I suspect W27C512 actually is a flash memory that is marketed as EEPROM as it can only be electrically erased as a whole unlike normal EEPROM.

[Midphase]

What app would you guys recommend for programming an EEPROM like the one I got?

The file I'm looking to burn on it is this one:

[Ian.M]

You don't get a lot of choice.  Usually its a case of using whatever software comes with the specific universal programmer.

[Midphase]

I had assumed that there would be a lot of software like AVRdude that can utilize various manufacturers' devices?

I guess in that case it makes the process a tad easier then.

[Electro Fan]

Probably best to start by becoming familiar with the software that is supplied with your Xegu T48.