27c160 EPROMs

RetroHacker

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I'm really getting fed up with these EPROMs. I've wasted over an hour trying to get ONE more to program. I bought this batch from an eBay seller, along with some 27C322's. The 322's program fine, and previous 160's I have had programmed fine as well. But this batch I've only gotten three to successfully program. The others all fail program verify, or won't erase. I can program them full of zeroes no problem, then erase, and either they won't blank check, or they hit errors when programming afterwards - like there's some bad cells that revert or something.

So, does anyone have some good 27c160's?

Thanks!

-Ian
 
Im pretty sure you mean 2716 and 2732 right? I have both, just got in 400 of each.
Its not uncommon to get a few bad ones in a batch. Out of these 800 I just bought, 3.5% wouldnt erase so they went in file 13.
I clean and erase all my used eproms before selling them. It help minimize someone getting a bad one.
 
Ian,

Look inside the erase window... Is the chip bigger than the window? If so, you'll have to set it in the eraser at an offset from the lamp so the light can shine diagonally down on the wafer to erase the parts not directly under the window. Once that's done, you'll have to flip the chip around so you can erase the other side that isn't under the window.

That's a common problem with the Hitachi 27C4096 chips that Capcom loved to use on the CPS1 and CPS2 boards. Those chips are a pain in the ass.

RJ
 
Look inside the erase window... Is the chip bigger than the window? If so, you'll have to set it in the eraser at an offset from the lamp so the light can shine diagonally down on the wafer to erase the parts not directly under the window. Once that's done, you'll have to flip the chip around so you can erase the other side that isn't under the window.

I had thought about that, having run into similar once or twice before. But the die actually does fit in the window. I've also had a couple chips where there was a bubble or bad scratch in the window, to similar effect.

I did go back and read the datasheet - it specifies 30 - 40 minute erase times... which is about four times what I normally use. So, it could be that these particular chips just really need to be cooked a lot. Normal chips don't take anywhere near that long. So, tonight, I'm going to put 'em in and nuke them for 30 minutes and see if that helps.

-Ian
 
eproms

I will check my stash. I know i have plenty upto 8 megs but i am sure i have some 16's on boards or pulls.
 
Bump.

Can also make use of some 27c800 (16 bit wide, 8 megabit), and 27c080 (8 bit wide, 8 megabit) chips...

I'll even take junk boards with soldered-on EPROMs. Anyone got any broken bootleg Neo carts?

-Ian
 
I might possibly have some of these. I just bought a couple thousand eproms but havent even unloaded the boxes from the truck yet. I know there were a few oddball ones I picked up but cant remember exactly what they are. Once I get all these parts checked in I will let you know what I have.
 
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I found AM27C2048, I think these are the breed your looking for? Im showing 180 in stock, they are NOS in factory tubes. Not sure if your interested in the 2 megabit ones.
I just picked up over 15,000 parts so I might run across some more numbers as I sort through it. I will post if I pull anything interesting.
 
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