Interesting 87' LM board I found

[cordes]

There's no bottom chip. It's from an 87' Reliant if I'm not mistaken. Looks like I could burn the bottom chip and a top chip and be set to use it in a TII setup though?

http://www.turbo-mopar.com/forums/photopost/data/858/P7080006.JPG

[Aries_Turbo]

thats a tbi computer.

i dont think all the drivers are populated.

[cordes]

thats a tbi computer.

i dont think all the drivers are populated.

I think it was a 2.5 TBI. Aren't the drivers in the PM with the LM cars?

[sdac guy]

I think it was a 2.5 TBI. Aren't the drivers in the PM with the LM cars?Yes the drivers are in the PM. And all the 87 turbo boards I have only have one 27c128 chip in it. The 86's used two 27c64 chips.

Barry

[ShelGame]

If you notice, it's missing 3 transistors (2 at the top of the pic, and 1 at the bottom - look for the ' C B E') that the turbo boards have. Not sure what they do, but I'm sure they are necessary. It's also missing 3 capacitors - 2 at the top and 1 at the bottom.

They're probably off-the-shelf parts. If you could figure out a suitable replacement, I'm sure it could be converted to turbo use...

[Aries_Turbo]

2 of those transistors are for the knock stuff.

the other might be for the 2nd injector drive circuit.

i know the knock ones are 2n4401 transistors.

brian

[ShelGame]

Not to mention, the timer chip is missing (the bottom chip)...

[cordes]

Thanks guys. It seems like this may be a fun and perhaps affordable project. The board itself is in great shape so I may go ahead with the procedure.

[ShelGame]

Any luck converting this LM? I found this link, might be a good place to get the timer chip (though I've never used this company before)...

http://www.marcospecialties.com/product.asp?ic=MC6840

[ShelGame]

Some interesting quotes from the old ECM Yahoo group...


For those interested in putting differant code in the logic modules, I
just put the 85 T1 stuff in a 87 turbo II ecm, the 171 .

The code was already proven relocatable. The lower chip moved from the
0xa000 -0xbfff range to 0xc000 to 0xdfff.

The 6840 chip must remain inactive till talked to.

Anyway, it "ran" on my simulator bench with a EPROM emulator and the
National ADC0808CCN a/d chip.
Now to get that simulator to put out 86 distributor signals...

Chad


You know, for some reason, I never even considered using TBI computers as a
source for turbo modifications.

Today I grabbed an 87 TBI logic module from an 87 Lebaron, for $9.95. The
PCB is identical to the turbo, there are only a few components not
installed. The 6840 timer chip (Z22) is missing, 2 transistors missing (10
cents each), some resistors and capacitors (2 cents each). In short, about
10 minutes with a soldering iron and I have yet another spare turbo logic
module.

This particular one I think I will modify as a test platform. Perhaps put
battery backed RAM into it with a parallel port programming interface,
instead of buying a ROM emulator.

Either way, if you don't mind doing some minor work with it, the TBI module
will work as a replacement for the turbo module, and that is good news from
a supply standpoint.

[Geoff Allan]


Sounds like if you add the missing parts, the TBI LM will work just fine as a turbo LM. You'll have to cut the keys off the red/blue connectors on your harness, though...

[cordes]

Thanks for the links and info Rob. I haven't started on this project yet, but I will try and get it going soon. It would probably help to motivate me if I actually had an LM car running right now.

[ShelGame]

Did you ever do anything with this Cordes? I'm thinking of getting a couple few TBI LM's to convert as they seem to be easier to get a hold of than Turbo LM's. I have 3 bad LM's I can pull the red/blue connectors off of...

[cordes]

I haven't touched it since I put it wherever I have it at now.