i have an 87 Trans am 350tpi....... i want to purchase a bunch of blank eproms.... the burning equipment is on the way... i know this is probably a stupid question, but it's the only way i'll learn....i see that digikey sells eproms, what is the part number for the correct eprom i will need to use?... i read the programming section on this site, but i think it only lists the 90-92 part number...(27c256-90) is this the correct number for my car also??..any help would be appreciated
Elias

 

oops the website i meant was JDR.com but doesnt' really matter, as long as someone could help me out

 

This appears to be the most popular option for the 165.

https://www.thirdgen.org/techbb2/sho...ght=165+29C256

-Matt-

 

ABSOLUTELY! For MAF 165 ECMs and SD 730 ECMs the AT29C256 is the ONLY way to go. No UV eraser, virtual indefinite life (compared to 25-50 times for an eprom) and only pennies more than a regular eprom. This is truly an win-win-win situation.

The ability to "erase and write" electronically in 1 pass alone makes the AT29C256 Flash Prom far more desireable than the "erase and wait" with the UV eraser needed for an eprom. Also, I have found times where I didn't quite erase long enough and while the PP said it programmed properly, my ECM didn't like it. So you constantly have to a little extra time on the erase cycle (with eproms) after so many burns to ensure the eprom is properly erased. After about 25-30 times you will now have to wait a VERY LONG TIME and usually at about that time, you will find the eprom won't program properly. So, beside being quite time consuming, the eproms themselves become another source of problems.

You couldn't give me an eprom for FREE now that I am using flash proms.

 

The correct eprom is 27c128, but 27128a will also work. I tried to use the 27c256 and the 29c256. I find that when you use a 16k code on a 32k chip you can't read the code again to make any changes. So you have to make the changes on the 16k portion then add the 16k blanked, then burn the chip. Is this faster? NOT for me. I switched back to the 27c128 chips, darned cheap on ebay. I bought 12 chips for 5.00+6.00 bucks shipping.

 

CP, did you try using the newer Windows Version of the Pocket Programmer? It allows you to write the 16K BIN on the 32K AT29C256 by specifying a 4000 Hex Offset. It doesn't require you to convert the 16K BIN to a 32K Bin and then write it on the chip. You just write the 16K BIN to the AT29C256 by specifying the offset. Just put 4000 in the "Start of Device" and it works just fine.

But even before PP got the Windows Version working, converting the 16K to 32K was only a 2 second job. Heck of a lot quicker than waiting for your 27C128s to erase, and it still doesn't resolve the "limited re-burns" of the 27C128s.

Since you already have the BIN saved on your computer you really shouldn't be needing to "read" the BIN saved on the AT29C256, but if you HAVE to, just read the AT29C256 as a 27C128 and it will read it as the proper 16K BIN.

I think you just didn't work with the software enough. There is no way you could erase, reprogram and re-read a 27C128 as quick as I could do the same to an AT29C256.

 

Your probably right Glen. I messed with the 256 Chips before I had my software update. I ended up selling the 256 chips. I didn't make a file to tell what i was doing at first, do now. I was thinking someone new to burning LIKE myself might find it easier to use the correct eprom to start with. With the way I do it now,wouldn't be too hard to keep track of what I'm doing. With my eraser I can erase 5 chips at a time, so I just run them through after I burn a few. I may try useing the 256s again. Because now I change the chip by one number every time I burn one, to find out just how it's running. Are you able to make the changes on the bin, burn it and then fill with 0000s?

 

Actually, it would be better for a new comer to just learn to do it right with AT29C256 flash proms so they don't have to buy a UV eraser. The only difference when you use the Windows Version of PP between a 27C128 and AT29C256 (besides selecting the right chip) is to set the Starting Address to 4000 for the AT29C256. Works perfectly then.

 

guys, i wish i knew about the flash proms before i ordered my eraser, but now too late, already on it's way....doah...

anyways i guess i'll ask more questions as i get along......

about editor programs.....:/? any recommendations on which one is easier and or more understandable to use? that is about the only thing i have not gotten yet
Elias

 

TunerCat is by far the easiest to use. Since you have MAF, the BEST TDF for MAF is the 6E. It's the best defined of all the MAF TDFs.

To go $6E, you must run the 1989 BIN (specifically the ARAP BIN) and disable your Cold Start injector. Make a new post on the subject and I think you will find most MAF guys prefer using the $6E over the $32 or $32B.

 

Glenn -

I've seen this mentioned before, but nobody has said why, so: Why does the cold-start injector (and VATS) need to be disabled??? I have an '86 Vette w/L98 and 4+3; TunerCat; ZIF mod'ed MemCal w/29C256. If I get the TunerCat $6E TDF file, and use the ARAP BIN, what difference will I see???

 

I'm not Glenn, but I'm qualified to answer since I've done this swap. The '89 (and later) TPI's didn't use the cold start injector since GM was able to inject additional fuel while the engine was cold using the 8 injectors instead of the additional 9th injector. Camaro's didn't get VATS until '88, so if you have an '87 or earlier Camaro, you'll need to disable VATS in the chip. Going with the $6E and ARAP is getting "the latest and greatest" for the MAF TPI setup, plus the $6E is hacked a lot extensively than the earlier codes.

 

...... Thanks Greg!

So, since I have an '86 L98 Vette, I wouldn't need to disable VATS or the cold-start injector; that's cool. All I'd need to do would be select Manual Trans, and I should be good to go. (For a starting point, at least).

I had gotten the AARL BIN with the latest MemCal for my '86; but that's a $32 def file...

So, I guess now I ask: Why is the $6E BIN more desirable??? (Or will I see why when I open it up?...Def file is "on order")...

 

Ummm, I'm guessing that you do have VATS, so you won't need to disable that, but since you do have the cold start injector and the $6E code doesn't need it, you'll need to disable it (remove the injector harness, pull out the fuse for it, or remove it and plug the holes). You'll want to start with a manual-trans bin since there are quite a few changes in the calibration between the 2, not just a single selection. The $6E is more desirable since there have been more variables defined that can be changed, but if you really need it depends on if the $32 def file has everything you need.

 

Greg, I would like to correct one of the statements you made above. It was 1989 when GM first put the VATS in our cars, not '88. You are quite correct about the cold-start injector.

So if Sarkee really does have VATS in his 86 Vette, then he would have to "enable" it using the '89 $6E tdf. And he could disable the cold-start circuit, by a number of ways. I just pulled the 3A fuse for now, plan is to install the plug kit when I pull the TPI setup this winter. Some folks leave the cold-start circuit in, even with the '89 ARAP bin. Might be kind of rich on startup however.

The '89 $6E tdf is the most desirable for MAF cars. Lots more tables and constants, plus this tdf gets more frequent updates. You can goto TC's website and look at all the paramters for any of their cals. But since Sarkee's Vette is a stick, he might not want to start with the ARAP bin. This bin was for '89 F-bodies with 350 and auto tranny. There should be some '89 bins out there for Vettes with stick shifters. Otherwise, take a 305 TPI bin with a stick, and make some changes.

Hope this helps!!

 

I guess this is one of the mis-communication areas between Vettes and F-bodies...I was told the ARAP *was* a Vette BIN...Aluminum head 350 TPI...In fact, that's what BCC lookup says...

http://holman.cs.uml.edu/~sdurphey/bccfind/

...But in any case, you are right on the manual trans...Although my manual trans $32 tdf file has the auto TCC points in it...

But looking at the BINs in the 3rd Gen archives should turn something up...If I can figure out how to identify it...

As for VATS, yes, my '86 Vette has the resistor-pellet ignition key. I know the resistance, and will be picking up a resistor from RatShack for emergencies, but until then I'll keep it Enabled.

From posts here & there, I understand the cold-start injector fitting is a strange (to automotive) thread/fitting size..."AN-4" I think it was...Something that Nitrous users are familiar with, the posts say...I'll keep an eye open for a "Nitrous Bottles Filled Here!" sign...