I picked up a used Hypertech chip for a 1988 Firebird 305/auto with the intention of converting the carrier to a ZIF socket and re-burning the chip for use in my 88 IROC 350/auto.

The interesting part is the box says 88 Firebird Anti-Theft...my 88 IROC doesn't have VATS...did the 88 Firebirds? Also the chip is marked as a 27256-25. Now if I just had the stuff to read the chip I could find out which half (upper, lower, or both) the info is burned into.

 

Are you sure it is for a MAF car? Sounds like it may have been intended for an SD car with that 27256 eprom.

 

88 was the starting year for vats so some got it some did not I have only seen it on 88 gtas but, I have also seen 88 gtas with out it so perhaps it was a late year or just an option at that time.

also the chip I got from a 87 formula 5speed had the # 27c256 this was a gm chip and yes the car was maf.

 

Depending on what's on hand, even GM supplies have used 256s in what are normal 128 applications. Sometimes 2x images, and some times 1/2 is 00s

 

Grumpy, I was just thinking about this and figuring that if the 27C256 is being used for MAF cars, then there is absolutely no reason why the AT29C256 Flash Prom cannot be used in the same way.

All the MAF guys have to figure out is how to get the 16K bin loaded on the 32K AT29C256 since they must use FILEPROM.EXE.

Simple solution would be to concatenate 2 16K BIN files into one 32K BIN file.

 

Or figure out which half of the chip gets used and create a 16K file of all zeros and concatenate the "real" 16K file with that one in the correct order. I've done some database programming and found that having unneeded data leads to confusion and sometimes problems.

------------------
John Guynn
1988 IROC 5.7

 

Does this mean that for the time being anyone running a MAF can't use the 29C256?

thanks,
Dan

 

No, technically it SHOULD work. If I had a MAF car, I would try it just to confirm. Just need someone with a MAF car to do it as described (place 16K instruction set in the top half or 16K in both halfs if you wish to be sure) and confirm that it indeed does work.

 

Tim Burgess may have suggested the solution last September.

You can find the thread here --> www.thirdgen.org/messgboard/Forum5/HTML/000098.html

 

Glenn91L98GTA wrote:


No, technically it SHOULD work. If I had a MAF car, I would try it just to confirm. Just need someone with a MAF car to do it as described (place 16K instruction set in the top half or 16K in both halfs if you wish to be sure) and confirm that it indeed does work.


I should try it and see. I think I saw a couple of eeproms on some old controller boards at the office, I should grap a couple and see if it works.
I'll let ya know...


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89 Firebird Formula
WS6 package,ZZ4 Crate engine
SLP 58MM TB, Edelbrock TES Headers
Random Tech 3" cat, SLP 3" stainless exhaust
9 bolt rear, Hotchiss swing arms, Lakewood panhard rod
Corvette 2/4 servo, kevlar band, full poly rear.
Centerline 16x8 rims, B.F Goodrich drag radials
Should be getting my Spohn SFC's tomorrow and my new Accel intake, runners and 24 # injectors in a couple of days too

[This message has been edited by LeeH (edited April 16, 2001).]

 

LeeH, its the AT29C256s that we are specifically discussing. Since they behave like a 27C256 (on read) but an AT29C256 for programming, they SHOULD work as people have made the 27C256 work for MAF cars.