Has anyone ever dumped the rom routine code at $5000-$5FFF or $6000-$6FFF ?

The routines at $5000+ is external hardware used during factory calibration.

An access to the $6000+ area will reboot the ECM.

RBob.

Don't want that

I keep seeing references to it but no info.
Did this communicate with a display or tuning device of some sort?
Any other ideas on what it did, does, or could do?

I believe there was some tuning/adjustment/display hardware connected to the back of the ECM that used the addresses you describe. If you look at section 2.5 in the Turbo_P4 document, you'll see some references to that hardware. It describes what variables were available on the HUD unit for different switch positions.

No doubt about it, BTDT, discovered it the hard way. New code for Highway lean cruise and every time it went into highway mode the ECM rebooted. Twelve seconds later goes back into highway mode and reboots again, and again, and again. Got off the road and put the last PROM back in. All I did was mess up the table address for the commanded AFR while in highway mode.

Also note that the RAM addresses in the L04xx area is on the external calibration equipment.

RBob.

It was a series of *boxes*.
The HUD was just degmented LED displays, not what you'd imagine in the way of a windsheild image.
Then there was an emulator.
And a data loggin devise.

For the very early 80s it was SOTA, but primitive compared to anything we have today.

Thanks,
Didn't know that. Tagged as such in my hac.
One more piece of the puzzle clarified.
Was hoping the routines could be of some use for modifying parameters but looks like nothing there.
Jp