Has anyone successfully swapped in a 2732 EPROM into a 1228079 ECM?

Based on a few very old posts, it looks like this was successfully done on a 1226026 (Crossfire ECM) but has anyone done this with a 4 year newer Quadrajet ECM?

My electronic guru guy I work with confirms that the 2732 pin outs in the following


Will definitely work... and makes the chip look like 4 N82S181's.

His only concern is that the N82S181 BPROM Chips that GM used are about 3 times faster then the 2732 EPROM Chip...(70ns response vs 200ns response) Has anyone tried this? Did it work?

And one more question There are lots of threads on this forum that state the 1228079 ECM and the LG4/L69/ZZZ/ZZ4 MEMCAL Chips were 2716 EPROMs and others that say that these chips are 82S181 Bipolar PROMs... Which are they? Who's right?

 

I'm sorry I can't help with your question although I do believe what you are trying to do is possible as the same strategy is used to run bigger (physically and electronically) 28 pin chips in TBI's with 24 pin chips.

If you don't mind me asking, what are you going to do once you are able to put a chip in the ecm? I'm not aware of any ecu files that available for the carbureted ecm's.

 

I've got one on my laptop that I use with the carb cars. Originated from my 1988 Cadillac Sedan Deville Broughams 307 Vin9 CCC setup.

 

You're right about that!

To date, as far as I can tell only two CCC Quadrajet ECMs have been hacked:
The Chevy 305 LG4/L69 (Camaro/Firebird/Monte/Caprice) 1987/1988 1228079; and
The Olds 307 LV2/LG8 (Cutlass, Regal, some Wagons, some 307 Caddies, Vista Cruisers, etc) 1988-1990 1228330.

I have the ECU/XDF/Tunerpro files for both. These files are NOT easy to find and for some reason aren't really posted anywhere (special thanks to members of this forum, Carb Hackers and Oldspower.com). I also have the BIN files for the 88 L69 Monte, 88 LV2 Cutlass and the two ZZ4 chips. My plan was to play with the ZZ4 chip and program into the 4 "quadrants" of the 2732:
1) Base Low output ultra low emissions from the LV2 (for my annual smog test)
2) Mileage/performance tune from the L69 (normal setting)
3) Factory Performance ZZ4 w/o ESC (scare the wife setting) and
4) Some crazy timing curve that I will try and dream up (it doesn't work setting ).

Fast 355 do you know if the 2732 chip is fast enough to emulate a N82S181 in this ECM? It looks like one of the guys on Carb Hackers tried this, but there never was a "final" "it works" (or it doens't work) post...

 

My suggestion would be very similar to what would be done in other similar situations.
Build yourself an adapter out of a "standard" chip socket. ( I like wire wrap sockets for the longer, larger pins )
Add the resistors and jumpers on the socket, burn a stock chip, and try it. You'll know real fast if the access times and such are sufficient. I suspect it'll work fine.
If it fails, you'll find yourself in an ECM failure mode, but should still be able to limp home.
Better, take the stock chip on the ride, so you can literally pull over, and fall back on stock.

 

This sounds pretty interesting.

I swapped my stock 86 LG4 ecm with the 1228079 1987 Monte Carlo SS ecm and the performance is so much better.

I would like to burn a chip with a custom tune, and willing to help if i can.

The prom code on the ecm was ACFZ, and i think its for the auto, but not 100% sure. (16069011 was the Part#)

 

this must be the most epic thread dig of all time but you dont by any chance have these CCC tunerpro files do you?

 

http://www.gearhead-efi.com/gearhead-efi/def/

no clue what you're looking for. but maybe here?

 

I've used 2732 PROMs in both the 1226026 (84 crossfire corvette) and the 1225550 (82 crossfire corvette) ECM's. No issues. You could use an adapter or do as I did and install a ZIF socket and modify the pin connections inside the ECM.

A better choice would be 28C16 EEPROMs. These work equally well and no EPROM eraser required. A similar adapter or ECM mods would be required.

Henry

 

zed-028,

The best TunerPro definition file I am aware of for the 1228079 CCC ECM is downloadable from this thread:

Burning chips for your 87-88 Monte Carlo

It's incomplete, but it contains a good number of parameters anyway.

I am pretty active over on that forum, if you search out my posts there (same username) you'll find all kinds of wild and crazy things I have done with that ECM.

Hope that helps.

 

I know this is an old thread but could I get some help with offsets for these 28C16 chips for my tbi that currently has 2732 chip in it. I tried stacking bins in tunerpro as this is a bigger chip and it would not work. Bin size should be 4kb? Chip size should be set to 16kb? What should the block size be? no offset? end justify bin in block?
Thanks in advance.

 

Old thread for sure. I don't think this is a stacking problem. Was your ECM using and working with the 2732 EPROM? The 2732 EPROM uses pin 21 as address line A11 (11 address lines are required for a 32K PROM). The 28C16 EEPROM uses pin 21 as a programing function and must be must be held high when in the read mode.
From the 28C16 Data Sheet :The M28C16 is accessed like a static RAM. When E and G (pins 18 and 20) are low with W (pin 21) high, the data addressed is presented on the I/O pins. The I/O pins are high impedance when either G or E is high.

 

Someone correct me if I'm wrong. I have no formal training/schooling on this topic...my observations are:
A 2732 EPROM bin size as you've stated is 4kb.
27C256 used in '90-'92 TPIs bin size is 32kb.
27C512 used in ~'95ish PCMs bin size is 64kb.
There seems to be some correlation with the chip number and size of the bin multiplied by 8.
This tells me a 4kb bin will not fit on a 28C16 chip.

 

To the best of my knowledge the 1228079 uses a 1 Kilo byte PROM (N82S181N). One Kilobyte is equal to 8 Kilo bits. The numbers (28C16, 2732, 27256 etc) on the PROM are in Kilo bits.

A N82S181N PROM is 1K x 8 bits (8 Kbs)
A 28C16 EEPROM is 2K x 8 bits. (16 Kbs)
A 2732 EPROM is 4K x 8 bits. (32 Kbs)

Either a 28C16 EEPROM or 2732 EPROM can be used to replace a N82S181N 1K (8 Kilo bit) PROM if the correct logic levels are applied to pins 18, 19, 20 and 21.

 

That's what happens when you necro-post and don't lay everything on the table...
^^^snakehips wanted to know if the 28C16 can be used in place of a 2732a specifically what offsets to use. 28C16 is a EEPROM and can be easily over written like flash memory vs 2732a UV erase yada yada.

Educate me...I wanna learn too........or not. I just modify 28 pin zifs so I can use it in a 24 pin EPROM ECMs.

Edit: Oh Duh!!! I read your 1st statement and it went over my head...after re-reading it, gotcha!!!

 

Yes my ecm is working with the 2732
It is a stacking problem I'm having with tunerpro what settings should I use in the bin stacker?
My programmer can select and properly program 28c16 chips, I just need help either with offsets to put a 4k bin on it, or how to stack them to fill the 4 4kb bins on the 16kb chip using tunerpro

 

I'm no pro at this but I thought I could either stack 4 4kb bins and program them into a 16kb chip (28C16) or put one 4kb bin into the correct address and make it work.

 

Just to clarify, the ROM image for the 1228709 is 8 kilo bits (or 1 Kilo byte). Therefore, it's possible to load 2 separate calibrations in a 28C16 EEPROM (28C16 has 16 kilo bits of storage space). Four separate 8K calibrations calibrations can be programed into a 2732 EPROM (32 kilo bits of storage space). Are you trying to load a single calibration into the 28C16 or are you using a BIN selector setup?

The first calibration in a 28C16 would use memory locations 0000 to 03FF
The second calibration in a 28C16 would use memory locations 0400 to 07FF

For a 2732 EPROM the memory locations for the 4 calibrations are:
0000 to 03FF
0400 to 07FF
0800 to 0BFF
0C00 to 0FFF

 

Just to clarify I'm using the 1227747 ecu with 4kb bin file that comes on a 2732. I'm trying to use the 28c16 chip in it. I tried stacking 4 bins using tuner pro but I think I have the setting incorrect tuner pro showed an error. Perhaps someone could post a tunerpro binstacker screen shot with the correct settings or let me know what offset to use to put one 4k bin on the 28c16. Thanks

 

OK, now I understand what you're trying to do. You're mixing Kilo Bytes with kilo bits. The 28C16 is a 16Kb EEPROM. It has 2 Kilo Bytes or 16 Kilo bits of storage. The 2732 EPROM has 4 Kilo Bytes or 32 Kilo bits of storage. Eight Kilo bits = 1 Kilo Byte. The numbers on the PROM are always kilo bits.

The 1227747 requires 32Kb of storage. The 2732 EPROM is the ONLY EPROM that will work in the 1227747. There are no 32Kb EEPROMS.

If you want to stack BIN's, all EPROMS and EEPROMS capable of storing more than one 32Kb use a 28 (or greater) pin device vs the 24 pins on the 2732 EPROM. This would require the use of an adaptor that would allow you to select between the multiple calibrations stored on the larger EPROM or EEPROM.

28 PIN UV erasable EPROMS:
2764 EPOM = 64kb (2 - 32kb calibrations)
27128 EPOM = 128kb (4 - 32kb calibrations)
27256 EPOM = 256kb (8 - 32kb calibrations)
27512 EPOM = 512kb (16 - 32kb calibrations)

28 PIN Electronically erasable EEPROMS:
28C64 EEPOM = 64kb (2 - 32kb calibrations)
28C128 EEPOM = 128kb (4 - 32kb calibrations)
28C256 EEPOM = 256kb (8 - 32kb calibrations)
28C512 EEPOM = 512kb (16 - 32kb calibrations)

 

Oh okay thanks for clearing that up. I guess I should of asked these questions first before I believed guys on this forum saying they've been using these 28c16 in the place of a 2732/2732A chip. Oh well, I only bought four of them, so I'm not out much cash.

 

https://reddevilriver.com/home-page/...-2732a-adapter

This adaptor would allow you to use a 512 Kilo Byte EPROM or EEPROM in place of the 2732 EPROM. It would also be fairly easy to modify it into a BIN switcher.

 

Thanks I'll check that out.