I've had a Romulator working on the 148, and 747.
Tired it on a P4 and it wouldn't work.

So, sent a 1227165, and a 1227730 to George to look at.

He said he's figured the problem out.

If your Romulator wouldn't work on a P4 send it to him for a fix.

 

any word as to Tunercat supporting the romulator as of yet? I emailed them but have not gotten a response on it. Just wondering since you work with them on the def files if maybe u knew of a release date whether its hopeful or accurate :-)

Dying to try that combo out and at least saving myself a small amount of time getting it dialed in close enuff to work on the final tune .

Since their have been a few small issues with the Romulator(which we all know they are addressing) do u think purchasing one now would have any effect on the Tunercat capability end of things? At least as far as the present version will accomodate Tunercat when it does support it?
thanks
jeremy
PS the hardware/software end confuses me more than the tuning so sorry if i asked something obvious:-)

 

Hey Grumpy - that's awesome! George already has my ROMulator. I just spoke to him on Friday, and he told me he had an ECU (didn't know it was yours), and it would another week or so. He must have found the problem right after I called.

THNK for the info.

 

i just recieved email that said that its a gm resistor pull up value that is wrong. so hopefully when they email me back i can include detials on the fix. peace out.would seem more logiacal to fix the ecm then touch the emulator.

 

Tunercat is working with the same hardware as you and I.
Until this fix, everything was kind of on a hold. Since he was having the same problems as all of us. Hopefully now that there is a hardware fix, he'll be able to get his sofware working.

If you want to kick back and wait, I'll be mentioning when things seem to be operating.

Hang in there, when you start getting to the stage that you think you know what works, you'll see you're wrong anyway..... LOL

 

Ehh??? sometimes you really baffle me.

Your proposing that everyone that has a P4 ECM, that wants a romulator, to open the ECM, find the correct resistor, scrape off the comformal coating, remove said, BTW its a SMT resistor, and change it to a different value to correct a problem thats a easy fix within the romulator.

One.. why?

Two.. have you ever worked with SMT devices? I've got about 8 years of working with parts, from 1208 to 0402. Fine pitch, quad packs, J-lead...

Three.. reworking the ecm, especially with data and control lines is foolhardy. Its one thing to change out a driver, another when your working with the microprocessor.

Four.. Most people do not have the skill to rework the ECM.. see above.

Its become plainly clear that while you may have some seat time burning chips, that one, have no training in electronics, or two, even understanding the effects of what you do...or worse suggest.

Sorry, I really don't like busting someones chops... however, people need to know that they need to take your suggestions with a grain of salt. cavi acroama

 

this is the email i recieved from xtronics.



GM inappropriately sized pull-down fix:
Important note as of 11/22/02 we identified a problem in GM ECUs that have an inappropriately sized pull-down resistor. (an amazing error to see in production electronics!) You can request an RMA to have your unit upgraded with this fix. All units ordered after 11/22 have this fix standard.



Return it insured to:

Transtronics, Inc.
3209 West 9th Street
Lawrence, KS 66049

Put this RMA number "W112302K" on the outside of
the package. Also print out a copy of this E-mail and write your
Shipping address and phone number on it and enclose it with the programmer.





Karl Schmidt EMail Karl@xtronics.comTranstronics, Inc.
WEB http://xtronics.com
3209 West 9th Street
Lawrence, KS 66049
Ph(785) 841-3089
FAX(785) 841-0434
Definition of Windows XP:SPAM, thinly disguised as an operating system--------------------------------------------------


ok saturn5 question to you. since obviously fixing the ecm is not a good idea. will the new fix for the romulator break it on other brand ecms such as honda,mitsubishi,toyota, ford ?this might not be a big deal for you but it bothers me. and you can take my advice any way you want. thats the beauty of free speech. if you dont like what i have to say then you are welcome to contradict. however i think your tone of comment needs to be looked at.

just my 2cents.

ps with the proper tools smt parts are not difficult to remove.I dont have these tools but alot of competent repair technicians do and i would send it to a tech.

 

First.. Did GM make a mistake. Possible. However, there are hundreds of thousands of P4 ECMs working just fine.. 10 years after the last one was produced. The fact the romulator had a problem due to " a inappropriatly sized pull down resistor" is wholly Intronics problem not GM's.

Second.. Will it cause problems on other ECMs. Again this is Intronics problem, and I'm sure Karl has checked other ECMs to make sure his fix hasn't caused other problems. Without having schematics of a Romulator in front of me, I can only say that changing the 10K resistor pack with a 100K pack will reduce the current thru the CE line.

Third..And my favorite.."ps with the proper tools smt parts are not difficult to remove.I dont have these tools but alot of competent repair technicians do and i would send it to a tech."

Which goes straight back to your first statement. Why rework the ECM, when 90% of the people don't have the tools or skill to do it.
But if you want, send yours off. Should only be 50 to 75 bucks to have it changed.

Fourth..There is nothing wrong with my tone. I have said nothing rude, used any expletive, or called you any names. I just have commented on the fact that your statements are not always accurate. If I have ruffled your feathers, maybe you should review your information before offering facts.

cheers, Bob

ps cavi acroama (reader beware)

 

this sound great!

Keep us updated on the -165 ECM.

But I think I'll learn to burn EPROM the old way first before I invest in a romulator.

 

Any chance to get the nitty gritty details regarding what the problem with the resistance values? It would be good to see some open dialogue in this matter. Are we talking address, data, or control lines? Pullup or pulldown? Buffered drivers or what?

Perhaps if it was suggested that someone wanted to correct the problem at the GMECM end of the business, some information would flow a bit regarding what the issue is. This would help others understand.

I've been playing around trying to get an EPROM extension to work. Using 541 drivers on the address and data lines, and considering what's needed in terms of pullup/down and ringing suppression. Kinda painful, since I guess I will need pullup/down on both ends of the buffer chips, but that depends on what is at the GM end of the business. So if we can learn something about what is at the GM end, it would be helpful.

So let's see if we can discuss some details?

Regards,
-Craig

 

From what I have heard thru emails with several people, GM used a 10K pull down resistor on the CE line. Intronics used a 10K to deactive CE and OE by pulling them high. This in turn put CE at 2 volts, deactivating the Eprom. Intronics "fix" was to replace their 10K's with 100K's. Karl's comment to GM's using a 10K pull down was "This is the dumbest thing I have seen."

cheers, Bob

 

GM ECMs were designed before the thing made by Xtronics. Therefore, Xtronics is wrong and not GM. Pull down and pull up resistors are choices made by the designer. GM did not make a mistake, Xtronics made bad assumptions and created a poor design.
Also, any device that is supposed to 'emulate' a ROM should not interfere with the existing hardware. Overall, it sounds like the ROM faker is a poor design to me. Especially when someone blames working hardware (GM's ECM) to be designed wrong.

 

Let me see if I have this straight.

-> GM has a 10k pullDOWN resistor going between the CE line and GND. This holds the line at GND (active) during the high-impedance ECM state unless it is called high by the ECM to go to +5v, which will deactivate the CE at the EPROM. Is this the case on the OE line also? What about the data and address lines?

-> Intronics folks used a 10k pullUP resistor tied between +5v and CE/OE. This pulls the line high when in the high-impedance state. Well, it would except that during the high-impedance state at the ECM, the GM 10k. Like the Intronics folks said, it's more common to tie lines to a pullup and then let them go low-active. Does seem a bit backward, but that's the way it is right?

-> The new Intronics mod gives a 100k on the pullup side, allowing the pulldown on the GM side to do its job. Also allows the EMU to do its job with systems that have wavering capability to maintain +5v during high impedance state.

I can see where the confusion came in if this is the case. Nice to see it being resolved. Kinda elegant really in a brute-force sense, should work with both systems. So how does it work? Is the RAM upload/rewrite suspended during ECM CE/read cycles in favor of data passing from the RAM to the ECM? Still seems like it'd be nicer to have multiple banks and just do the hand-off during off-cycle. Maybe that's it, I'm speaking out of turn.

Am I understanding this correctly? If so, then I still don't know what's wrong with my setup. Shouldn't need pullups/pulldowns seeing that GM already has it going. Guess I need proper termination, too slack so far.

 

a completely random thought here. what if gm intentionaly did this to prevent people from using equipment like the romulator in there ecms ?? just a random thought since its not just one but all the p4 ecms that have the same issue? im not accusing but it sure does seem awful convenient.

 

Wait...what was that...did you hear that? I think it's a black helicopter....

 

i spoke to george at length about the resistor pack change in the emualtor. he say it will not afect its ability to work with other ecms. so i gieuss leave the ecm alone fix the emulator. not a big deal. rather gald to have cleared that up. and criag chrysler will sue you if you hack or sell modified version of there roms. so whos not to say gm didnt.

 

Is there a number 3 on the side??

 

What GM did is completely normal in their design. Xtronics just did not design their emulator well enough to take things such as this into account.
Their design shouldn't be loading the CS line anymore than the factory eprom does. That is why Xtronics is modifying their design...........cause they screwed up. Their fix by changing the resistor is still a bad design..........although it will work with GM ECMs now.

GM didn't put anything into the ECM to try to stop people from making enhancements to it.

Also, Xtronics site claims that there older version of ther Romulator was a piece of sh**. Whose to say in a year they don't build a good one and claim the current on is also junk.

By installing a different device into the eprom slot does not mean that the ECM has been modified.

Craig,
I looked at the pictures of the eprom 'switcher' in the sticky post of yours. I noticed that you still do not have any logic on there that syncs with the CS changing. That still could be your problem.

Also, you can't terminate at the eprom side side with series resistors. This will not have the desired effect you are looking for. You need to use some parallel termination. This requires a lot of knowledge / analysis of the GM ECM.

J

 

Crap, no series termination? Read my mind on that one. Would be the easiest way for sure. Parallel, like you say, is a bear since you've got to know something about the drivers & receivers and the circuit LRC character. Not to mention worrying about too much current. Hmm, I guess I could just try something and see what happens, but with three octal buffers between the ECM & EPROM, my 'breadboard' is getting pretty cluttered. Might be time for a trial PCB.

I tried some more dickering with the O-scope, but it was rather inconclusive. Since the unit I'm using has no trigger sync line or dual input, it's kinda hard to see what's going on. But just in terms of the shape of the curves, it looks like there's a lot of signal bouncing around, with overshoot and settle-out time on the same order as the pulse width in some cases.

It's weird, the EPROM extension I rigged up works fine as an extension off of the Pocket Programmer for reading the chip content, but it fails when it comes to writing to it and doesn't work on the ECM. So I think it's wired right. I wouldn't really expect it to work as is, retrospectively, with NO termination or pullup/down the way it is. Figured I'd try simple first...

Oh, and about the sync logic, I put something together, but it makes things a little more complex and needlessly so I think. Most of the experience with the switcher is that switching on-the-fly will at worst cause a slight stumble. May not want to switch 'mid-pass', but it seems pretty safe at a stoplight or something. If it becomes a problem, I definitely could go that route. I was HOPING that the extension thing would pan out easily and that would lead directly into a more complex and remotely-mounted switcher...

 

Thanks guys, nice to see nothing's changed.

Intronics designed their Romulator without having a P4 in their possesion. No having one there, was just a matter of not having one there, and I'm sure there are others they didn't have. The cure was just sending them one to examine. While George may not agree with the GM designers that's his option.

In hindsight, it's alot easier to design something quote unquote better.

Suggesting someone do something that you don't have a clue about doing yourself is, again silly.

At times any more I wonder if this list is a service or a disservice to the new guys. With so many experts, expressing opinions as facts.

 

Being a newbie myself, I hear what you are saying. It is good to hear people discussing things such as this. It helps protect us newbies from bad equiment and shows us what good equipment to buy.

The emulator should tri-state ALL signals on the existing bus. It should not load any.

Craig,
You could try matching the impedance of the existing signals that are ringing. Then termination resistors would not be necessary. If the ringing signals are strictly uni-directional then you can use series termination. Typically, bi-directional external busses use line drivers that are capable of supply more current upon switching. You could use this for the data bus and uses term. resistors for the other signals.

These are my opinions, not the facts. In engineering there are no facts, you just make stuff up.

J

 

Bravo!

 

I see Xtronics has posted on their web site the pull-down resistor problem, and to request an RMA to get your unit fixed, if they don't already have it.
http://www.xtronics.com/memory/romutator.htm


-Bill Rauch
90 383 MR Vette Hardtop

 

This is good news.

I'll probably buying one when I get more exp. to prom changing/burning.....