I'd like to install a zif socket where my ash tray is. That way I can take the chip out for security reasons AND it makes changing chips a LOT easier.
I ordered a few zif sockets, they came today but I wasn't here to sign for them.
I also have a zif receptical with long prongs. Is it going to stay in the socket without the plastic eprom carrier piece?

------------------
, Jon (350 TBI!)
91 Red My website

 

I'm not sure but I don't know if that will work. I think the excessive distance from the ECM may cause some problem, I'd wait and see what how some of the more knowledgeble guys respond.

I can deffinatley relate with the hassle of removing the eprom and I've probably only done it like 20 or so times, but I'm sure if it were possible to remote mount it somewhere it would have been done by either Tim or Glenn, and I've never heard mention of it.

 

here's where Mike Davis put his remote PROM. Look for "August 29, 1999".

http://www.eecis.udel.edu/~davis/z28/ecm_swap/


James

[This message has been edited by james_fearn (edited May 15, 2001).]

 

I had too much length on my ZIF socket ribbon cable (3+ ft), and had some problems. I think I'm still having problems with a mere 24", seems to be chip-dependent. I'd recommend putting it as close to the ECM as you can and still get to it easily. When you get up in by the dash cluster, fan controls, radio and all there's a good bit of RF interference which could affect the PROM link.

Then again, maybe I just used crappy wire & such...

 

What I'd really like to know is how to get leads into the socket without falling out. They seem to be a real PITA with that plastic carrier piece. I remember trying to just fit an eprom in and all it did was fall right back out.
Thanks for the info about having the extension too long. I'll try a couple things, first I'll try to shield it and if that doesn't work I'll end up putting it right where you did with shorter length wire.

------------------
, Jon (350 TBI!)
91 Red My website

 

The digital signals to/fro the eprom
won't maintain their integrety much
beyond 6-8 inches..

mike


------------------
My Z28, ZZ4swap, TPI EPROMs

 

okay, well then I'll have to leave the chip near the eprom or move the eprom. I'm also working on a switch so I can have a few chips for economy, track, blah blah blah and valet (40mph speed limiter )

------------------
, Jon (350 TBI!)
91 Red My website

 

I got 3 zif sockets in the mail today. I hooked it up to a zif receptor and the receptor held itself in the stock chip socket. I'm very pleased with how easy it was to convert to a zif, I hate that plastic piece! I'll post a couple pictures if anybody shows intrest.

------------------
, Jon (350 TBI!)
91 Red My website

 

Slide the ZIF or end of the cable into a eprom holder (needs long leads). Then insert as you would normally.

Some cars are real bad RFI wise and this won't work in, cause of the long wires. Might wrap, the *extension* cable with some AL foil

 

------------------
, Jon (350 TBI!)
91 Red My website

 

That sure is a small shifter.

[This message has been edited by steve8586iroc (edited May 20, 2001).]

 

Keep in mind it's not just noise, but also the extra capacitance and transmission line effects from running the EPROM so far from the board. And there's really nothing you can do about that unless you want to go nuts with buffers, and then you're adding extra delay anyway, so who's to say that would work out any better.
By all means give it a go, but just keep in mind that you are working well over the expected load on both the address buffers in the ECM and the drivers in the PROM.
Bruce, you have an ECM testbench right. I trust you have a scope as well? It might be interesting to try hooking this up and seeing how the edge rates and prop times fare as you increase wire length, on both the address buffers vs. clock, data vs. clock, and even clock skew. Hell, now that i think about it, you might really **** the whole ECM off by hooking such a large load on the clock.
...ed

 

Ah...ed, did you look at the picture I just posted? Do you think THAT is too long ?

------------------
, Jon (350 TBI!)
91 Red My website

 

What would it take to mount the ecm on the outside of the dash just opposite of the original location. Or you could make a door that would hinge upward with the ecm mounted on it so that when opened and latched to the dash pad it would be facing the floor board.
I'm just thinking out loud so don't laugh at me to hard.

Steve

[This message has been edited by steve8586iroc (edited May 21, 2001).]

 

I'll probably leave the ECM on the floor for now . That's where it's been ever since the engine swap.

------------------
, Jon (350 TBI!)
91 Red My website

 

Jon,

What is the PN for the receptor and where did you get it. That looks like a pretty good setup. Have you tried it too make sure it works right? Do you think you could post a pic of just tyhe receptor?

thanks,
Lars

 

I can't remember the part numbers nore do I have the paperwork infront of me (back at school). The zif socket I got was a 28 pin and the zif "receptor" was only 24 pin (same as eprom) so I had to use a dremel to shave off 2 of the zif prongs. Then I just stuck it in, it isn't too secure but it does work when you want to just make quick changes. It's just pressed in right now so it falls out if you aren't careful. I'm still working on it but I have an extra ecm to try this out. It's going to end up being my "test and tune ecm." Check out any electronics part supply and tell them you need a quick release zif socket and receptor with long leads. They should know exactly what you're talking about. If you can't find it let me know and I'll mail you one of my extra 28 zif sockets.

------------------
, Jon (350 TBI!)
91 Red My website

 

old topic brought back up.

i was wondering, could you extend the wires that plug into the ecm about 5 feet and still be ok. i was thinkin, it would work rather nicely to have the ecm right my center console/glovebox. no? what do you think.

 

That's a good question. I don't see anyproblem with the extra length wire except that it would take a lot of wire and a lot of time to move it .

------------------
, Jon (350 TBI!)
91 Red My website

 

heres a tip for ya

Use flat ribbon cable like the ones you can find inside a computer. now this is the trick use a resistor in series with each data and each address line, you will want to use a small value some thing like 47 Ohms or so.

this will help eliminate some of the noise generated by the switching digital signals
the lines inherently have capacitance as does the uP by adding the resistance you soften the the edges of the square wave a low pass filter if you wish. this should work as long as you dont go too long with the cable

[This message has been edited by v8power (edited July 27, 2001).]

 

I am willing to bet you that the power of the ECM will be an issue here if a cable setup is used. The system just isn't designed to broadcast and receive signals from the EPROM on any length of cable. Now, if a guy were to slap a repeater on the circuit, he would be in pretty good shape. But then there is the whole impairments issue and its effect on the signals. Exactly how does, or should I say can, the ECM deal with corrupt data from the EPROM? Filters could be used, but one must know what the noise margins are in order to use the right ones. I just don't forsee this as being a feasible idea, but I could be wrong.

Maybe we could hook-up a DSLAM to the ECM and an ATU-R to the EPROM and run it back to the trunk.... a little ATM PVC action...... lol

------------------
1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, BBK 52mm TB, Edelbrock TES, gutted Cat, Flowmaster, CAI w/K+N cone, AFPR, TB bypass, !AIR, !A/C, !EVAP, ARAP, 2300 stall, Alum. Driveshaft, Hotchkis STB, '99 Camaro seats.

Coming Soon!!: Fourth gen 3.42:1 rear, Spohn LCAs and Panhard.

 

I am afraid you are misinformed

there is no brodcasting going on

first this setup is like 10 years old (SLOW *** PORCESSORS)the rom is a 90nS part

a digital signal is just 0 volts or 5 volts. there is no power issue here as the the proms inputs do not sink any current nor does the processors. the only problem you may encounter is cross talk or noise as most people are used to.that is what the resistors are for

if you are worried about interference from other wiring use some of that shielding stuff it looks like the stainless braid you use on hoses under the hood. you then ground one end of it and run the cable through the center voila no external noise.

------------------
Objects in mirror are more stable than they appear
www.members.home.com/v8power
4BBL to TPI in the works
86 350 5spd custom made weld in subframe

 

I understand what digital signaling is. It still uses power to send it's signal and that signal will degrade as it travels on it's circuit. That is where I think the trouble will be. As far as broadcasting and receiving goes, I should have just said receiving since the EPROM only receives a signal from the processor, alters it, and lets it back out to the data bus. The bottom line is that the digital signal will not travel forever, it will 'fall apart' unless it is amplified. Amplifying is a delicate area as well due to impairments that may be present and not wanting them to be amplified with the core data.

Crosstalk, or impairment(s), is another problem with this as well, but like you said, a drain will remedy that issue, somewhat. It is impossible to shield the circuit from ALL impairments, but the ones present in a car should be able to be suppressed.

I am interested to see how, and/or if this works, but I personally am skeptical...

------------------
1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, BBK 52mm TB, Edelbrock TES, gutted Cat, Flowmaster, CAI w/K+N cone, AFPR, TB bypass, !AIR, !A/C, !EVAP, ARAP, 2300 stall, Alum. Driveshaft, Hotchkis STB, '99 Camaro seats.

Coming Soon!!: Fourth gen 3.42:1 rear, Spohn LCAs and Panhard.

 

I believe the car will still start and run without a chip in it. Its called limp home mode.

------------------
1991 Z28 305 5spd 1LE, TES headers, dual cats, 3 Chamber flowmaster, Comp cams .488/.495 212/218, 187 head castings with bigger valves, self-burned eproms.
Gained 20HP by porting and polishing my EGR passage.(some people take this seriously)

All work done by myself, and proud of it!

Find a .bin on the internet and want it burned? I'll do it for you!

 

Yes I do agree the digital signal will not propagate for ever. there will be losses caused by the internal restance of the wire
A logic 1 or 5 Volts is accepted as a high as long as it is above 2.0V(from the data sheets)
so that means the voltage would have to drop over 2.5 volts (being quite conservative)

now tha maximun the prom can supply is 400uA

that means the wire has to have a minimun resistance of 6.25 KOhms generally the current never gets that high and the resistance never gets that low(unless you have ALOT OF WIRE) so the signal integrety is not at question here. it is the length of wire until the noise intuced is greater than the processor can handle and still interperate valid data. there should be no reason a few feet would not work. providing proper shielding measures are taken.

I am not tying to antagonize here I am an Electronics designer/developer so I do have a good back ground in this. I just want to make sure you under stand what can and cant be done

[This message has been edited by v8power (edited July 31, 2001).]

 

No antagonism taken . I am an engineer (intern) so I have a little background on this as well. The issue that keeps catching for me is the actual power behind that 5v signal. I just am not thinking that the designers of the ECM would have provided enough for it to be strong enough to travel any distance, so to speak. I would think that you could move it some distance, but not all that far. You know how the product people are, they always want to cut costs and use cheaper equipment - especially when we (the engineers) advise against it .

Don't you mean the max the PROM can handle is 400uA and not supply? The actual EPROM does not supply any power, right?

Another issue would be the clock input for the EPROM. How will it be affected if the signalling is delayed (all be it, a very small delay, but how sensitive is this equipment)?

I don't know if this is all that big of a movement(people wanting to move the location of the EPROM) for us to worry about anyways. I am most likely not moving mine.

Laterzzzzzz

 

so like i said. what about just moving the ecm to the glovebox, any problems with power or voltage drop there? the only electrical info i have to go on is stereo stuff.

mainly what i would be worried is the solder content and if it would cause resistance changes from the sensors original signals.

besides the time to do it, would there be any unobvious problems like delay by adding 6 feet to every wire going into the ecu so that you could put it in the center console?

[This message has been edited by snflupigus (edited August 01, 2001).]

 

I like that idea, and I was about to repost your question, but when I got to the bottom, you'd already done it.

I also wondered if it might be practical to install the ECM backwards, e.i. with the socket facing the back of the car, and then making an access hole in the cooresponding place on the dash. Possible?

 

Might even be able to make it the same size as the ALDL hole so you can just pick up the plastic cover from one and use it on the dash as well. Am I shooting blanks?

 

.

[This message has been edited by v8power (edited August 02, 2001).]