Could someone please give me the exact details for the flash prom in a 89 vette. I have the UV ones but am tired of having to use the light and would like to get some flash. I have searched around and see that everyone is using the AT29C256. The problem is when I went to DigiKey there are 2 pages worth of these and I am no electric genious. Mechanical perhaps, but not electrical IF someone could post the exact specs. i.e., AT29C256-12JC-ND I would greatly appreciate it. Thanks

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http://www.corvetteforum.net/c4/ski_dwn_it/
<b>67 Chevelle</b>
509 Merlin Crate Engine
585 Hp 637 Ft/Lbs
*************************
<b>1989 White coupe</b>
Open air box, Modified mass air, TB bypass,160 Stat, manual fan switch and lower temp switch, MAT sensor relocated, Air foil, gutted cats, flowmaster mufflers.

Soon to have Roller rockers.

When I die, I want to die quietly in my sleep like my grandfather did,
not screaming in terror like his passengers

 

I can't tell you the exact part number, but you want to look for something that says 28 pin DIP (Double In-line Pins).

 

anyone else with specifics or advise?

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http://www.corvetteforum.net/c4/ski_dwn_it/
<b>67 Chevelle</b>
509 Merlin Crate Engine
585 Hp 637 Ft/Lbs
*************************
<b>1989 White coupe</b>
Open air box, Modified mass air, TB bypass,160 Stat, manual fan switch and lower temp switch, MAT sensor relocated, Air foil, gutted cats, flowmaster mufflers.

Soon to have Roller rockers.

When I die, I want to die quietly in my sleep like my grandfather did,
not screaming in terror like his passengers

 

Okay, I looked at my DigiKey and Mouser catalogs and couldn't make heads or tails of their part numbers. So I went here www.jdr.com/interact/item.asp?itemno=gr-atmel
and found 29C256-12PC ($4.39 ea.) and AT29C256-90PC ($5.55 ea.). Both are 28 pin flash proms that should work. The first one is 120ns, which will work. The second one is 90ns, which is probably faster than you need, but it won't hurt anything. They seem to be pretty reasonably priced.

The only thing I'm not sure about is that these are 5 volt proms. I'm not sure if the application requires higher voltage proms, say 12.5 volts. Anyone else want to jump in and help?

[This message has been edited by davidjon_99 (edited October 11, 2001).]

 

The AT29C256s work fine on a MAF car IF the Programmer is working properly. The ECM reads the AT29C256 just fine. You will have to load the 16K BIN properly onto the upper half of the 32K AT29C256. There are a number of methods to do that.

 

I'm using JDR AT29C256-90PC FLASH RAM 32K x 8 90NS 28DIP EPROMs in my 1227165 Corvette ECU with no problems. They were $5.55 ea back in July.

I have a Digi-Key low-profile ZIF socket on a V8 MemCal; works fine. ECU EPROM cover even fits.

I "double/stack" the 16kb BINs to load the 256 chips. Hey, whatever works...