Use multiple PROM loads in your ECM
 

There was a post on the electronics board regarding a PROMPAQ II, from adaptive technologies, which allows you to use multiple PROM loads in your ECM & I responded with the following which describes how this may be done, fairly easily, if you have access to a PROM programmer:

You can actually make that type of device, fairly easily, if you have access to a PROM programmer. Get a 27C512 (64K x 8) PROM, (from Digikey, or any electronic parts store)and put multiple loads in it. For example, if your ECM uses a 32K PROM, the 64K PROM will hold 2 separate loads. If your ECM uses a 16K PROM, the 64K PROM will hold 4 separate loads. Use the upper most address bit (A15) to select which of the two loads to use for an ECM that uses a 32K PROM, and use the two upper most address bits (A15, and A14) to select which of the four loads to use for the ECM that uses a 16K PROM. You may connect the address pin(s) to a switch (switches), or jumper block(s), such that the address pin(s) is (are) connected to +5 volts (upper left hand pin on the PROM with the pin ID notch to the left), or ground (lower right hand pin on the PROM with the pin ID notch on the left). For the TPI systems that use a "module", you will have to cut out the original PROM from the module and solder a socket in its place for the new PROM - remember to read & save the stock PROM data before cutting the PROM out of the carrier.

I did this on my '92 Z & it works great.

Here's the address map for the PROM loads:

32K PROM ECM:
A15 = 0; 0x0000 - 0x7FFF
A15 = 1; 0x8000 - 0xFFFF

16K PROM ECM:

A15 = 0, A14 = 0; 0x0000 - 0x3FFF
A15 = 0, A14 = 1; 0x4000 - 0x7FFF
A15 = 1, A14 = 0; 0x8000 - 0xBFFF
A15 = 1, A14 = 1; 0xC000 - 0xFFFF


Tim

Tim,

So in your app. which will be similar to mine when I convert to a 730.. do you have a SPDT switch so for the first half it is switched to GND and the second it is switched to +5v?

Thanks

------------------
-=Jeff=-
89 Corvette Coupe White with Black Grand Sport Stripe
-=ICON Motorsports=-
Check out my mods on My '89 Vette

Jeff,

Great question! I was just getting ready to ask Tim that myself!

Tim?

Tim

------------------
TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

In the single address pin application (2 x 32K), there is one SPST switch. The pole connects to the address pin on the PROM socket, and the two contacts on the switch, that the pole may be switched between, are connected to the PROM socket +5 VDC, and ground pins.

In the two address pin application (4 x 16K), there are two SPST switches. One pole of each switch is connected each of the two address pins on the PROM socket, so that each address pin may be controlled independently.

The PROM pin numbers are as follows:
+5V: pin 28
gnd: pin 14
A15: pin 1
A14: pin 27

Pin 1 usually has a dot by it, or the end of the IC that pin 1 is on has a mark on it.

Tim

From your response.. it sound like you are using a SPDT not s SPST..

a SPST will have 2 pins only.. basically either open or closed

a SPDT will have 3 contacts.. the middle typically is common (where the Address pin connects). then one of the other pins will go to ground and the last to 5v..

a SPDT will act like an on/off either to one side or the other.. but have connection paths through both states.. a SPST will have a path in one direction only

Cheap Diagrams ('.' represents contacts) ( '/' represents the switch which goes to either of the contacts on a DT switch):

SPST ./ .

SPDT . ./ .

DPDT . ./ .
. ./ .

DPST ./ .
./ .

I hope this all makes sense

Jeff

Yes, you are correct...I meant SPDT, not SPST.

Tim

For everyone else here...

SPDT - Single Pole Double Throw
SPST - Single Pole Single Throw

Tim

------------------
TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

One last question.. Where did you mount your switch ? I don't think Length will matter too much since it is just a H/L TTL change.

Also inorder to switch from one to the other Key needs to be off correct?

I think I have my plan for Perfomance and emissions in one Chip.. Yahoo!!!!

EDIT= Which Burner are you using? do you burn each file separate or combine them to burn them?

[This message has been edited by -=Jeff=- (edited September 29, 2000).]

This is great! I'd seen reference to it in the past, but lacking the excellent detail which you've provided. Thanks a million for the post!
-Craig

What's the normal state for pins 1 & 27? Grounded in the carrier? I guess they have to be 'lifted' in this application, right?
Also, I'd heard that you can make the swaps 'on-the-fly'.

Tim,

Quick Question....

I reviewed the EPROM pinouts for the 512K EPROM. What I don't quite follow it this:

OK - Wire A15 (Pin 1) to the common pole on a SPDT switch. Then wire one pole of the switch to pin 14 (Ground) and wire the other pole to pin 28 (VCC / +5V). Does this mean that pins 1, 14, and 28 (A15, GND, VCC) are still plugged into the ECM but also have jumper wires coming from them to the SPDT switch? Or, are one or more of these pins not plugged into the ECM?

Tim

------------------
TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

now if it is possible to switch bin files "on the fly" then it would be possible using a RPM activated switch could "kick" in a more agressive program in conjunction with boost or nitrous activation....what possiblities.

Traxion, the pins for ground and Vcc power the chip. i believe that Tim is picking up ground and power from these points only to trigger pin 1 hi or low. However pin 1 is lifted from the socket and triggered manually with the switch.



[This message has been edited by SATURN5 (edited September 30, 2000).]

Hmmm...I tried this with a National NM27C512Q-120 tonight. Loaded it up with back-to-back 27c128 programs merged into one, and then tied pins 1(A15) and 27(A14) to pin 28(Vcc +5v). Lifted both pins 1 and 27 from the carrier. ECM choked. Tried it with the pins lined up to the ECM (probably not the wisest thing), and that also choked. Tried the same chip with no cross-ties or pin-lifts but with the duped-out code, and ECM still choked. Normal 27c128 runs OK. Maybe sonething squirrely with the Nationals?

Anyways, I'm not through trying and am open to comments or suggestions, particularly with respect to what you guys have found to be a robust chip brand/type.

Craig,you merged the bin files into a 32k bin file? or two 16K files? with A14 and A15 high activates address range 0xC000-0xFFFF, is your file located there? If you are using 16K bins, that means that 4 maybe loaded into the chip. that also means that you are using 2 switches correct?
16K PROM ECM:

A15 = 0, A14 = 0; 0x0000 - 0x3FFF
A15 = 0, A14 = 1; 0x4000 - 0x7FFF
A15 = 1, A14 = 0; 0x8000 - 0xBFFF
A15 = 1, A14 = 1; 0xC000 - 0xFFFF

with four possible states. I'm guessing the ECM is confused by the 32K file. If my theory is correct. I'm very interested in doing this...with a 165 ecm its possilbe for four profiles...at your fingertips.
I'm new at this so if I'm wrong, please no offense just my train of thought.


[This message has been edited by SATURN5 (edited September 30, 2000).]

Right. I had four 16k programs for the '165 stacked on top of one another in a 64k file. Dumped it to a 512k chip. Set both bits high. It thus should have looked at C000 starting address. Tried running it on a '165, so it should have been looking for 16k of addressing.

TRAX,

Sounds like VCC and GND are still connected on the MEMCAl but also to the switch.. Pin (1) A15 is hanging and wired to the switch only..

Jeff

Jeff,

Cool - thanx. I was sure that VCC and ground were still connected but I didn't know about A15. Hmmmm ... now I just need to get a switch, a coupla 256s, and another GM CalPak that I can rip apart.

Tim

------------------
TRAXION's 1990 IROC-Z
Best Time = 12.587 @ 107.97mph (1.710 60ftr) on the long runner setup.
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels. Stock Wheels. No Weight Reduction.
Gunning for NA 11's with the MiniRam II and Hooker LT Headers.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

Jeff is correct. The address pin lead from the socket that would normally be soldered to its corresponding contact in the carrier is connected only to the pole of the switch. The pin in the carrier that would normally be connected to that lead in the PROM socket is not connected to anything - the switch is now controlling that address pin, not the ECM. The power & ground leads from the carrier, that you tap in to for the switch power & ground must still be connected to the PROM socket, to power the PROM.

Tim

If anyone has this kind of thing working for 16k ('165) code on a 256 or 512k-bit chip, please let me know the details of your application and what brand/speed/model chip you're using.

Craig, you combined 4 bins to equal one 64K bin. correct? I talked with my boss about this topic and mentioned your problem. He said that you must load the bins individually and assign the address for each using the programmer. I hope this helps as I am also looking into doing this,oh also he said that switching on the fly may not work as the ecm needs to reset. I'll try it anyway... Bob