Alternatives?

[scooterwrench]

Are there any other flash chip #s that can be substituted for the 27SF512? I was going to buy a ZIF socket from Mouser and figured I'd get a couple chips too but they don't list the 27SF512.

[NomakeWan]

Tons and tons and tons and tons and tons. Your ECM doesn't actually use that chip anyway; it probably uses a 27C256 (or smaller!), which is an insanely common chip.

Like, if you're actually looking for a flash-rewritable chips, then something like the W27E257 would work. But honestly I don't bother with EEPROMs for these old applications. The chips are cheap and not hard to come by, just grab a handful of 27C256s and be on your merry.

[scooterwrench]

My 7747 uses 2732 PROMs but I'm thinking of dropping the dime on a 7427. That W27E257 isn't coming up either.

Eventually I'm going to invest in an EBL but probably not until I drop in the 355.

[scooterwrench]

What about these?
https://www.jameco.com/z/AT28C64A-15...MOS_74827.html

[stew86MCSS396]

If the picture is correct, the pin width spacing is wrong^^^.

I have no beefs with the '7747 except the slow baud rate it spits out the data. With a '7427, you'll get more data points faster and can hammer out a tune quicker. Should you stick with a '7747, you should consider this modification that allows you to use a 28 pin EEPROM vs the 24 pin 2732A.

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?172-7747-Flash-Chip-Conversion-(27SF512)

I suppose if you used this zif socket, it will accommodate either pin spacing but make sure the zif socket has the correct spacing that gets soldered into the ECMs board. https://www.newark.com/productimages...B/42260842.jpg

[scooterwrench]

Thanks stew,
I'm not going to try and do much with the 7747. The 7427 is on it's way. That will be another Q&A thread.
Where did you find that quick release socket? I like that! If the pins line up I would have to make a spacer for the cover but I'm OK with that.

[stew86MCSS396]

TBH I don't like them for the reason they don't fit under the cover.
https://www.jameco.com/z/28-6554-10-...le_104003.html

If you're dead set on using the '7427, advise that you get a EEPROM with 512k capacity as that's what the '7427 uses. With the zif mod linked^^^you'll still be able to use the 512k EEPROM with the '7747. No sense in buying something that only supports one ECM.

Shifting gears to '7427, you're gonna want a spare memcal that can be modified to accept a zif or take a chance screwing up your original or use a memcal adapter.

[scooterwrench]

I went with this one for the lower profile;
https://www.amazon.com/Aries-28-526-...3716047&sr=8-5

[scooterwrench]

Just ordered three 27sf512 proms.

[stew86MCSS396]

With all these acquisitions, I’m excited for you but which burner are you considering unless you already own one. Hate to see you think that you’re making great progress only to realize you’re still missing a piece of the puzzle.

[scooterwrench]

This one;
https://www.ebay.com/itm/385913991757?var=653585960648

NomakeWan claims they work good. Had a hell of a time downloading the driver but I got it done in the end.

[NomakeWan]

The previous iteration of that same device has indeed been a workhorse in my lab over the years. Used it to program chips for 85 Corvettes, my 90 Corvette, and a buddy's R32 GT-R. Also used it to flash various Atmel microcontrollers. It just lives in my lab hooked to an old XP laptop from 2009 to churn out chips.

[scooterwrench]

I'm close to doing the 7427 swap and came up with a brainstorm. My idea is to run a ribbon cable out of the PCM and install a 28 position Aries ZIF socket to the inside of the glove box. That way I don't have to keep pulling the PCM out every time I burn a new chip. If successful I'll post pics.

[NomakeWan]

That's very similar to how devices like the Moates Ostrich work, so yeah, that works too! Best of luck!

[scooterwrench]

Whatever happened to Craig Moates?