I am just checking on this little tidbit, I would think that the eprom should be erased when they arrive. There is no need to program them at the factory correct?

The reason that I ask is because I am trying to rule out the possibility that my pocket programmer II has gone on the fritz. It seems that no matter how much I tried to erase my old chip, it would not verify that it was erased.

Just for ****s and giggles, this morning when the new EPROMS arrived, I threw one on the programmer to see if it could be programmed... no such luck.

Do I need to erase them from the factory? If so, will 10 minutes suffice usually?

Also, they say they are 27128A rather than 27C128's. Does that make a difference? '89 165 MAF car.

 

Anyone? I'm bored at work and want to get this stuff cleared up. Take a stab at it!

Would it hurt to try to erase my new chips even if they are already erased? (pocket programmer error causing them to appear to not be erased when in fact they are)

 

I would never consider using an EPROM unless I erased it first.

Tim

 

Ok, I tried to erase the NEW eprom. I still get the damn pocket programmer telling me that the chip isn't erased. I am gonna try it on a 15 minute cycle to erase it. If that doesn't work, should I call the manufacturer and see what they recommend or should I give Craig Moates some money and get the stuff to switch over to the Flash Proms?

 

No, I would just try increasing the time a little longer.

Depending on the eprom mfg, they can take anywhere from 10 - 20 minutes to erase the first time. I start with 10, and if it doesn't "check out" I erase 5 minutes more and another 5 minutes more. I have yet to have one go beyond the 20 minute (second 5 minute erasure).

Then, I add 1 or 2 minutes every 3-5 burns after that. If I was able to make it work at 15 minutes the first time, then around the 3rd -5th time I will erase at 16 minutes, next 3-5, 17 minutes and so forth.

I also found logging the number of erasures and time useful in maximizing the eproms life.

But, in all honesty, a Flash Prom (AT29C256) is the best of all. They are only a few dollars more and so far I have never had one fail due to too many erasing/re-burnings.

Good luck.

 

I'm really, really glad after reading that portion of the post. Bullet dodged! I finally did something right in this whole "DIY PROM" thing...

 

Glenn, I believe that my pocket programmer is the culprit! No matter how many times I hit the Blank Check button on the thing, it will come up differently every time. EXPECTED FF Found 60 or FOUND 21 or FOUND 00. But they alternate... mostly all 00's but a few 61's and 21's mixed in there.

Anyway, the new chips are erased... they register all 00 And that means that I cannot program them.... according to the pocket programmer. Should I go for another 5 minute cycle to see if I can get them to go for all FF's?

So how easy is it to get into the flash proms? Just buy them and maybe a ZIF adapter? If so, I know what I am ordering tonight. I planned on making it to the track this weekend and I am sure as hell gonna try!!

 

It's been a while since I used regular eproms. But I thought that eproms had to be hex 00 if blank, while Flash Proms were hex FFs (different type).

One thing to make sure is that you have the PP at the proper setting. I know that when I occasionally have the Prom Type on the wrong setting.

As for the Flash Proms, contact Craig Moates. He has a sticky on the board. I recommend getting his adapter (with ZIF socket) and a couple of Flash Proms.

To buy Flash Proms from an actual Electronics Distributor, many have a minimum order size.

 

Well Glenn, if they are supposed to be all 00 I should be able to program them. However, the programmer will not let me program them while they are 00's.

I remember seeing a post by Grumpy and him stating that they all need to be FF and if they erased to 00 then the chips were bad... or somthing along those lines.

Thats why I guess the programmer searches for FF and when it doesn't finf FF it won't reprogram.

Time to call Xtronics I guess...

 

Definitely should be FF's everywhere on an EPROM when it's erased properly.

When you correctly erase an EPROM, all the holes are correctly stuffed with electrons (ie all the bits are set "high" (1)). You get the program you want by switching off (0) the appropriate bits.

John

And bnoon- good on yer mate! It's good to score a goal. You'll have it sorted out so soon you'll wish you had a problem to solve again

 

So basically my programmer is telling me that the chips are full.... full of 0's? And thats a bad thing correct?

Screw it, time to go 29C256 or whatever. But... if my programmer is having problems (of course it could be my DataraseII having the problem ) then I may not be able to program the flash chips either