Scott,

None of specs for these programmers (according to the Needham website) have any mention of supporting the M27C256B by ST. Is this a concern?

Also, do you know if their PB-10 or the SA-20 would work for this?

Thanks!

The EMP-11 and EMP-30 support the entire ST product family.

I am in the process of upgrading my EMP-10 to an EMP-11
(list price = $334.95, including Windows software).

Here are the specs for the ST (FDIP28W, insert-mount) chip:

M27C256B

256 Kbit (32Kb x 8) UV EPROM and OTP EPROM
5V ± 10% SUPPLY VOLTAGE in READ OPERATION
ACCESS TIME: 45ns
LOW POWER CONSUMPTION:
– Active Current 30mA at 5MHz
– Standby Current 100mA
PROGRAMMING VOLTAGE: 12.75V ± 0.25V
PROGRAMMING TIME: 100ms/word
ELECTRONIC SIGNATURE
– Manufacturer Code: 20h
– Device Code: 8Dh

DESCRIPTION

The M27C256B is a 256 Kbit EPROM offered in
the two ranges UV (ultra violet erase) and OTP
(one time programmable). It is ideally suited for mi-croprocessor systems and is organized as 32,768
by 8 bits. The FDIP28W (window ceramic frit-seal package)
has a transparent lid which allows the user to ex-pose
the chip to ultraviolet light to erase the bit pat-tern.
A new pattern can then be written to the device by following the programming procedure. For applications where the content is programmed only one time and erasure is not required, the M27C256B is offered in PDIP28, PLCC32 and TSOP28 (8 x 13.4 mm) packages.

Scott,

Please excuse me for what might seem to be some dumb questions, but I'm not an electronics expert.

How were you able to find out that this was the correct chip; was the one in the computer marked? Does the EMP-10 support this chip? I see support for 27C256 or 27C256B on some programmers, but not with the "M" in front.

Also, JDR seems to have this chip as well (but again, I'm no expert):

http://www.jdr.com/interact/item.asp?itemno=gr-epromcircuits

EPROM 32K X 8 120NS 28CERDIP M27C256B-12F1 $2.99

Is this the same chip?

Thanks!

Willy

Willy:

While the density, speed rating, and form-factor (28-pin, insert-mount) for the part you specified may be the same as the OEM part (EPROM), I think the wisest/safest means of archiving your existing LH chip is to use an "apples to apples" approach.

Specifically, I recommend using identical manufacturers, so as to avoid any unexpected (unpleasant) surprises. All blanks are cheap; however, "a penny saved..." applies.

Please also be aware that I cannot and do not condone software piracy; I merely am trying to solve my stalling problem and to share my experience(s) with others.

As soon as I try my "E-Gas control unit swap-out experiment," I will let everyone know the results, thereof.

Thank you,

Here's the deal.

I had a problem with my check engine light coming on. The error code I was getting matched an issue that Mercedes documented on a Service Bulletin. The Bulletin recommended replacing the computer, but not with the the same MB part #. Through some investigating on my part, I found that the difference between the new and old is simply the software revision. Although the MB Part #'s are different, the Bosch #'s are the same.

Now, since I was able to find a computer at a salvage yard for a relatively cheap price (not the new software version, but the same exact one), I purchased it. After installing it, I went to my mechanic and had the computers reset and all of the codes cleared. It now seems like my problem has disappeared. I'll give it a few more days to be sure.

I'm not sure if the code on the chip changes as one drives, but I heard that it did. What I'd like to do is copy the code/chip from the working computer and put it into the original one (again, they were both the same software revisions) to see if I can get it to work without getting the check engine light to come on. If it works, I then have a good computer that I can play with and maybe send into Jetchip to have upgraded.

That's my plan anyway!

Willy

Willy,

The "C" means it's a CMOS technology EPROM. These are slower than other non "C" type proms made with bipolar technology (such as a AMD 27256).

These chips exhibit slower propagation times (100-120ns) as compared to to the bipolar versions (20- 50ns).

You can use almost anything that has a "C" in it. To wit here's some 'C' technology with an 'N' and/or 'M':

National Semiconductor and Fairchild: NM27C256
Fujitsu: MBM 27C256 w/ or w/o a 'B'
SGS-Thomson: M27C256 w/ or w/o a 'B'
ST Microelectronics: M27C256 w/ or w/o an 'B'

The one you found should program ok: M27C256B for $2.99

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Here is the purported fix to my stalling problem, according to a local Shop Foreman (who showed me a SIEMENS tech manual which itemized my problem, exactly):

E-GAS Control Unit for 119 Motor (1993 Mercedes-Benz 500E)
OEM Part # 124-545-4532
*MUST* be software version 23/92 (23rd week of 1992) or >

I have yet to try this; however, please stay tuned...

Kind regards,

Scott,

maybe coming to the end of the road! And I'll bet you'll be happy.

They probably do not have one of those, so were will you get one? Look around in various parts houses, etc?

Standing by for the conclusion. . . .

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Scott,

Did you not say that the vehicle is a "Starmark"? Is your mechanic a Mercedes Dealer? Where do you plan to get the new ECU?

I was able to replace my computer with the same exact SW revision and it solved my problem. I only did that because I could not find one (yet) with the newer revision #.

Think about it, if you had that computer in the car without any problems earlier, and if others with that same software revision don't have that same problem, then why would a new software revision be needed. My guess is that the ECU chip in the computer takes updates (learns) and gets "reprogrammed" somehow as you drive. I bet if you were able to get a copy of an original chip and popped it into the car it would work. This may be a great reason to backup your "bin" once you purchase the car.

Bosch and Mercedes probably know (from experience) that after some time and under certain circumstances things happen to the car. They then come out with new software to code around these issues.

Sounds like pie in the sky... I know.. but just a thought in case you have to flip the bill for the computer and you can't find the newer version.

If you can, please post the Bosch part # for your computer. I'll bet that the the old and new computers both have the same Bosch # (although different MB #'s).

Good luck... I follow this thread with great interest.

Willy

Jim where can I buy the sport grill that's on your E320 ?

thanks, Y.O.

__________________
'94 E420 ///AMG
Mono-White
AMG Body Kit
18" Brabus IV's w/Pirelli Nero's
Clear corners
Burl Wood Shifter
Sport Wood Wheel
Avantgarde Grille
Remus exhaust

Yuri,

Looks like Performance Products carries it for $199 (Ref#6131). They also have the Hood Star replacement for $39 (Ref#99-797). I can't seem to find it on their website,
but it's in the new W124 Catalog.

http://www.************************
1-800-243-1220

Willy

__________________
Willy

'94 E420 White

Mods
-------
Berg Werks Keyless Entry
Buzzer replaced with Chime
Dash Light Upgrade
Burlwood/Leather shift knob
Alpine CDA-9815 Head Unit
2002/2003 16" C Class 7-Spoke Wheels
Updated "Chip" to fix Code 19 problem

Yuri,

Willy's info is correct.

To finish it, used 6 coats of clear coat. Make sure to degrease the grill before applying clear coat. Gives it a nice sheen.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

It looks much nicer that stock, I think I will buy it.
As far as installation goes, how though ?

thanks guys, Y.O

__________________
'94 E420 ///AMG
Mono-White
AMG Body Kit
18" Brabus IV's w/Pirelli Nero's
Clear corners
Burl Wood Shifter
Sport Wood Wheel
Avantgarde Grille
Remus exhaust

Well looky here!!

http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=577385686

Willy

__________________
Willy

'94 E420 White

Mods
-------
Berg Werks Keyless Entry
Buzzer replaced with Chime
Dash Light Upgrade
Burlwood/Leather shift knob
Alpine CDA-9815 Head Unit
2002/2003 16" C Class 7-Spoke Wheels
Updated "Chip" to fix Code 19 problem

Now Willy, you want one too for your white Beauty ?

__________________
'94 E420 ///AMG
Mono-White
AMG Body Kit
18" Brabus IV's w/Pirelli Nero's
Clear corners
Burl Wood Shifter
Sport Wood Wheel
Avantgarde Grille
Remus exhaust