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EEtools TopMax. Problems verifying blank M27c160s or erasing.


palindrome

Question

I posted a similar thread on KLOV but there are some really knowledgeable people in here that can help too :)

 

I have a couple of ST M27C160 EPROMs that someone sent in for programming but both appear not to erase completely. Out of fear of damaging the chips, I'm reluctant to keep them exposed to the eraser any longer.

 

Both chips seem to have the exact same data at offsets 0x400 & 0x401 with the values 0xDF00 and 0x4E00 (See attached).

 

pastedImage.png

 

Is it likely that both chips are faulty or won't erase in this location only ( seems unlikely to me ). Or would this be an issue with the TopMax's software/hardware ? Anyone else have this kind of issue with M27C160s ?

 

I have tried the software on two different machines, one was quickly rebuilt to rule out the possibility that the PCIe card was the culprit. One desktop has a built in parallel port, the other has a parallel PCIe LPT card ( WCH chipset ) which I bought recently. Both exhibit the exact same results but I have no problems working with other chips ( reading, writing, verifying and testing logic devices ).

 

Both run XP, the machine with the PCIe card runs XP under VMware.

 

Any clues ?

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If they are eBay EPROMs then for some reason the 27c160 have a huge DOA rate , I bought 60 a while ago and 14 weren't blank and wouldn't erase like the 2 you have.

Tried filling the buffer with all FF and writing but they all fail during programming , erase again and a couple of them passed blank check but failed verify @5% VCC .

Something very strange I have noticed with all these that are dead is if you scrape either end there is always remnants of clear tape on them but this is rarely on the ones that are ok.

 

If you do ever program them make sure to verify them at 10% +/- VCC , if they fail that they will fail in the game soon after , and also have pin check on.

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I had me too a lot of issue programming 27C160s bought on eBay with m EETools ChipMax2.Actually the programming went fine but verify failed all the time.I think it's really an issue with devices and not of the programmer itself. Edited by caius
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My understanding is that these chips come off NBA Play By Play.

 

Thanks for the input guys. I was going to order a couple more but that seems somewhat risky based on your experience.

 

How about alternatives such as the flash version, MX29F1615 ? ( my TopMax definitely supports those ).

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I posted a similar thread on KLOV but there are some really knowledgeable people in here that can help too :)

 

I have a couple of ST M27C160 EPROMs that someone sent in for programming but both appear not to erase completely. Out of fear of damaging the chips, I'm reluctant to keep them exposed to the eraser any longer.

 

Both chips seem to have the exact same data at offsets 0x400 & 0x401 with the values 0xDF00 and 0x4E00 (See attached).

 

[ATTACH=CONFIG]127850[/ATTACH]

 

Is it likely that both chips are faulty or won't erase in this location only ( seems unlikely to me ). Or would this be an issue with the TopMax's software/hardware ? Anyone else have this kind of issue with M27C160s ?

 

I have tried the software on two different machines, one was quickly rebuilt to rule out the possibility that the PCIe card was the culprit. One desktop has a built in parallel port, the other has a parallel PCIe LPT card ( WCH chipset ) which I bought recently. Both exhibit the exact same results but I have no problems working with other chips ( reading, writing, verifying and testing logic devices ).

 

Both run XP, the machine with the PCIe card runs XP under VMware.

 

Any clues ?

 

Ive struck this a lot in the past, and i had about 50% success by giving the window a VERY thorough clean, and then 3-5 minutes in the UV box.

 

It seems all it takes at times is a speck or a fine scratch to stop the full erasure on a 27C160.

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Thanks for the heads up.

 

It just seems odd that both chips would have the same stuck bits at exactly the same memory address.

 

The MX29F1615 seem to be a very good alternative and they're electrically erasable. I will consider those in the future instead of the 160s.

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Thanks for the heads up.

 

It just seems odd that both chips would have the same stuck bits at exactly the same memory address.

 

The MX29F1615 seem to be a very good alternative and they're electrically erasable. I will consider those in the future instead of the 160s.

 

Can but give it a go mate eh? If it doesnt work youre no worse off ;)

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The MX29F1615 seem to be a very good alternative and they're electrically erasable. I will consider those in the future instead of the 160s.

 

Yes, they could be a good option.There are also SSOP/TSSOP 16Mbit devices, it could be easy to build a DIP adapter for them.

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It's a bug... There are a couple of different types of those ST 16Mb EPROMs and only one works as ST.

 

Read/Write them as the OKI chip of the same size (MSM27C1602CZ) and it'll work just fine.

 

Thanks for the heads up.

 

I did try that initially but what threw me off was when it popped up with an error saying there was poor contact with pin 43 even though it's only a 42 pin chip. So there's definitely bugs in the software.

 

However, if I ignore the above error it blank checks fine and programming/verifying checks out.

 

BTW.. I read on various arcade forums that the TopMax doesn't like PCI parallel/LPT cards. Just a heads up that this one I bought works fine under VM/Windows XP. It uses the WCH chipset.

 

 

https://www.ebay.com.au/itm/PCI-E-PCI-Express-DB25-Parallel-LPT1-DB9-RS232-Serial-Port-Card-Adapter/221785303231

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