I saw this in the Motorbooks Power Tech Series, How to Tune and Modify Your Camaro. It's on pg. 93. It's call a PROMPAQ II made by Adaptive Technologies. It allows you to have 4 different PROMs in one ECM and a key switch to change between them. This is NOT like the JET 6 Pack chip. This allow you to have 4 of your own chip. They come with a valet chip and then you add your stock chip (if you want) and up to two more modified chips. This would be great to allow you to pass smog with the stock chip, have your own burned chips and the valet chip would keep others from hot rodding your car when you drop it off somewhere. Anyone know about this? L8R ------------------ Mike Schwartz aka chevymike '92 Z28, 5.7, Teal Hardtop "Don't Outlaw High Performance Cars, Outlaw Low Performance Drivers!" Mike's Camaro Z28

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

Yeah! What Tim said!

Hey man, you are outta sight. Too bad I don't speak Electronicus Geniusicus Maximus!!

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FORMULA 350 TK
Southern California 3rd Generation F-Body Organization©

Uuuummmmmm.......OK

I was thinking more on the lines of a plug and play. This is a little further then I wanted to go at this point. Thanks for the info.... I think.

Tim I like your idea...however, I have a question. How do "conveniently" swith between the different programs? Thanks.
Draino

You may use a SPDT switch to select between two loads, or two SPDT switches to select between four loads. This topic was discussed in more detail on the PROM board.

Tim