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Erasing and programming 2532 EPROMs

DeltaDon said:
I believe the old TL866 could provide a higher programming voltage than the newer T48. So it might be possible that the T48 can't reach 25v.
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The OP said: I verified that Vcc and Vpp are correct at the chip during the programming cycle. Vpp generally holds at 25.2V but sometimes varies anywhere between 24.9V and 26.2V, which seems to be within tolerance, based on the datasheets.

But that would have to be tested with a scope to be sure, not a meter, because it could be transiently collapsing for short periods of current pulses, he did not say if the voltage looked ok on scoping, it sounds like a meter's measurement.
 
maxtherabbit said:
The T48 is the replacement (newer) product from the same vendor who made the TL866II. What I am saying is that I am skeptical of gigabite's claim that the newer product won't program a 27c256, since that would be such a large step backwards from the same people.
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My T48 won't program *any* 27c EPROM that I have. It will always fail at a predictable point for every EPROM, even if the EPROM has been completely erased.

I've tried parts from 27c64 all the way up to 27c1024 from my IBM PS/1, and the T48 couldn't program any of them. It will get a bit farther along if I plug the T48 into an externally powered USB 3.0 hub, but it will again still fail at a predictable point. The only way I've been able to get the T48 to program an EPROM is to do it in steps. I have to let it program until it fails, then find the address where it failed and tell the Xgecu software to start at the next address and do that until it finishes writing out the EPROM. This is also a failure prone process, because the last programmed byte where the T48 fails is sometimes corrupted and the EPROM has to be erased and started over. That's stupid and puts a lot of excessive wear on the EPROM so I just got another programmer.

My GQ4x v4 on the other hand with external power has zero issues programming any of my 27c EPROMs. It will program first time, every time with no errors.

I know the T48 isn't faulty, because it will program newer EEPROMs just fine, even really large ones. I think I've done up to 256 megabit EEPROMs.
 
d_a_parker said:
I'm working on a Commodore PET 8032 and wanted to use the PETTESTER ROM to trace a possible memory issue. I have two used TI TMS2532JDL-45 chips, and ten (supposedly) NOS Hitachi HN462532G chips.

I was able to erase one of the TI chips and program it with the EDIT ROM for the PET, which then worked fine. But I have subsequently been unable to erase or reprogram ANY of the other chips, and I'm at my wit's end. After 15-20 minutes in the eraser, they contain garbage with a smattering of FF sprinkled in. When I try to program one using my T48 and 2532/2732 adapter (which did work with that first TMS2532), I get a garbled version of the source image for the first 16-32 bytes, then just total garbage. No matter what I do, I can't seem to erase or program these 2532s.
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If I may share my experience,
I discovered that I had ruined some of my TMS3532 (I couldn't erase them) because they were actually TMS2532B (written on the back of the chip) with Vpp = 21.5V.
No problems since I've been using 21.5V.
I'm not familiar with Hitachi EPROMs, but the "G" is probably an updated revision with a lower Vpp.
 
P101 said:
If I may share my experience,
I discovered that I had ruined some of my TMS3532 (I couldn't erase them) because they were actually TMS2532B (written on the back of the chip) with Vpp = 21.5V.
No problems since I've been using 21.5V.
I'm not familiar with Hitachi EPROMs, but the "G" is probably an updated revision with a lower Vpp.
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I found something similar, in that the TMS2532A (21.5 Vpp parts) if they are used parts, and were accidentally programmed in the first instance with 25V, while they worked at first fine for that one time programming, if attempts are made to erase them later, it fails, as they have been over programmed. This is why it pays to avoid used A suffix parts, you don't know their programming history and I think many of them were initially programmed with 25V setting at the time, and problems only show up later when attemps are made to erase them and recycle the part. I always advise to get the unused NOS TMS2532JL, programmed with the GQ 4x and there will be no troubles. I have not seen B suffix parts , but from what you have said they are the same as A suffix part.
 
Hugo Holden said:
I have not seen B suffix parts , but from what you have said they are the same as A suffix part.
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P

Thread 'I'm looking for information on this 2532 EPROM'

Does anyone have the datasheet or information on this EPROM?
It's a Texas Instruments 2532, pre-programmed.
I'm asking this information because I read that they're faster than the standard ones and that they need to be programmed at 21V instead of 25V.

TI 252-10.jpgTI 252-10 rear.jpg
 
Sorry for the late reply here. I did eventually get 2532 EPROMs to work with my T48! I ended up building a better adapter using a 24-pin DIP socket inserted into the T48, as opposed to my previous method of sticking DuPont wires into it directly. I also used AI to determine that the T48 needs to have +25V on the Vpp pin to write, but +5V on that pin to read. So I had to add a connection from +5V to Vpp with a pullup resistor, and also a diode to prevent the 25V from backfeeding into the programmers 5V output. Once I perfected the adapter (which is still quite janky, but far less than my original), my T48 could both read and write 2532 EPROMs just fine.

I'll try to get a circuit diagram together, and a photo of the adapter.
 
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