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DavidGriffith / minipro-import-test

An open source program for controlling the MiniPRO TL866xx series of chip programmers
GNU General Public License v3.0
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ST M27C256B chips all fail strangely #89

Open DavidGriffith opened 6 years ago

DavidGriffith commented 6 years ago

I have a tube of ST-branded M27C256B UV-erasable EPROMs that all fail to have stuff written from 0x200 to 0x27F. The first bad byte written is 0x00. Subsequent bad bytes are 0xFF. Then from 0x280 on, the chip contains the expected data. Would this be caused by a failure in the chips or might there be something wrong with the controlling program? I don't have any other means of programming chips.

DavidGriffith commented 6 years ago

Does anyone here have a working programmer from the 1980s or 1990s and a UV eraser? I'd like to provide you with one or two of these chips so we can determine what the problem is. It could be trouble in this software, trouble in the tl866's firmware, or simply a bad batch of chips.

This chip is still popular enough that I feel it's important to get to the bottom of the problem.

DavidGriffith commented 6 years ago

Created by: szg0000

I have UV EPROMs, I will try to write with minipro.

DavidGriffith commented 6 years ago

That exact brand and part number?

DavidGriffith commented 6 years ago

Created by: elosha

I don't have an eraser, but if you could send one device of your batch to Germany, I could try to program using a Willem or TaskIt. For the sake of advance in this issue ;)

DavidGriffith commented 6 years ago

Could you email me with your physical address?

DavidGriffith commented 6 years ago

I found a data sheet for this part: http://ecee.colorado.edu/~mcclurel/STMicro_M27C256B_EPROM_2384.pdf

Programming voltage is 12.75V +/- 0.25V

DavidGriffith commented 6 years ago

I sent CPUWIZ over at Atari Age two of these chips which he programmed on a Xeltek 610P without trouble.

@elosha, To get to the bottom of this, I think you'll need to get an eraser. The problem appears to be in the TL866 CS/A firmware or in devices.h.

See http://atariage.com/forums/topic/275512-m27c256b-eproms-and-minipro-tl866-trouble/?p=3989251 for CPUWIZ's test.

DavidGriffith commented 6 years ago

Please hold on buying that eraser for a bit. I have a couple more tests I'd like to run involving the official software and different firmware versions.

DavidGriffith commented 6 years ago

Created by: elosha

Thank you, David. I'm trying to buy an eraser until your EPROM arrives.

Really wonder why this exact device is causing trouble. Maybe the batch didn't turn out 100% perfect, the TL866 programs slightly out of specification and the combination of both makes the error appear. But just a guess …

107 could be helpful in this issue. For example, I could check for correct programming voltage more easily if I knew how it is defined.

DavidGriffith commented 6 years ago

Word of warning... don't try to flash your tl866 using @radiomanV's program while you have Virtualbox running. At least for me, Virtualbox will automatically latch onto the tl866. When the connect and disconnect happens with the firmware updater, Virtualbox will grab the tl866 and cause a failed erase or write. Fortunately this is easily recovered from by just trying again, or shutting off Virtualbox.

DavidGriffith commented 6 years ago

I just checked programming some M27C256B chips with our minipro program and the official program. I tried with firmware versions 3.2.61, 3.2.80, and 3.2.81. Each time with our minipro, the programming failed exactly as I described above. Each time with the official program (versions 5.91, 6.60, and 6.70), the programming succeeded without a hitch. So, I'm positive now that the problem is with our implementation.

DavidGriffith commented 6 years ago

I have no experience with those Chinese erasers. The one I use is something made 30+ years ago in California.

DavidGriffith commented 6 years ago

Created by: elosha

Thanks for the hint, be careful! 🔨 I have access to an old Windows XP laptop for updating.

So I will get an UV eraser. The Chinese are in that business, too, with a cheap and tiny device for around 15€ on Ebay. Is it usable?

DavidGriffith commented 6 years ago

I forgot to mention that I used @radiomanV's firmware updater compiled for Linux, not the Windows version. I sent him a pull-request that updated the README.md file to include instructions on how to compile it for Linux.

DavidGriffith commented 6 years ago

@elosha, I have not done so. Is the physical address you sent me earlier still valid? Shall I send you a chip now?

DavidGriffith commented 6 years ago

Created by: elosha

@DavidGriffith I have not received an IC from you, did you send it or not? Just asking to be sure ;)

Can we be sure that those Singaporean M27C256B are genuine? Maybe a relabel …

DavidGriffith commented 6 years ago

Created by: DOSputin

Had similar problems with EPROM M27C256B that were branded as ST M27C256B Singapore and date coded between 1000-1140.

The first bad byte written is 0x00. Subsequent bad bytes are 0xFF.

Yeah, that sounds familiar.

By chance I discovered that I could read and write these UV chips properly by using the definition SMJ27C256 @DIP28 HEX 0x9704 instead of M27C256B @DIP28 HEX 0x208d Another large batch of the ST M27C256B Korea have no problems with the I/O using the standard definition.