Getting started with PCM hammer

[Gampy]

JHSimpson,

If you need an m68k instruction reference the best is here: MarkeyJester’s Motorola 68000 Beginner’s Tutorial

-Enjoy

[Broke4speed]

Ok, this is an ABSOLUTE newb question that I just can't seem to find an answer that satisfies my 'want to know' urge. I have NO problems with PCM hammer at all, and everything works flawlessly...but I've been constantly doing 'full writes/clone' because I have NO idea what the differences are in the choices. What is contained in the "Parameter", "Calibration", "Operating System", and "Boot" sections? Like, if I make a bunch of changes to the tune in the various 'calibration' areas (by Tunerpro's definition...Engine calibration, trans calibration, etc), what write should I do?

[antus]

Ok, there are two main sections, operating system (includes the boot sector), and calibration section. Most the settings you want are in the calibration section. That is the minimum operation you need to write a particular change like VATs off, or change the fueling, or disable some codes. It is the least risky, and in most cases its easy to recover from if something goes wrong.

Then there is operating system, which is like the operating system on your computer. It runs the PCM, and it makes assumptions about how the tune is layed out in the rest of the chip. Different operating systems have different or no bugs, different features too. You might need to do this if say your operating system is not well supported by tuning tools, and your car was updated later from the factory but your pcm never had the updates installed. So the car is compatible with a newer operating system (OS) and the newer one is well supported. When you do this, the boot sector generally needs to be erased. If something happens - laptop goes flat, cable is pulled out etc, when the boot sector is erased and before its re-written there is no way with software only to fix it. You need to get out the soldering iron and specialist tools to remove the flash chip and put it in a programmer or install BDM. Its still reasonably safe - especially with pcmhammer that does boot sector last after the rest of the flash has worked, and unlike commercial tools that erase the whole thing in one hit at the beginning of the operation opening you up to more risk. Most of the time you'd do the OS flash once when you need it, then go back to calibration flashes.

Having said all that, pcm hammer has the unique feature of using CRC32 to look for changes, and so even if you do an OS write, if the OS is the same it'll be able to tell that it doesn't need to re-write those sectors and so it'll skip over them.

Then there is the paramater block. Thats the place that stores the vin number, security link to your key, BCM etc. If you change OS you probably want to write this too so its formatted to suit the operating system. If you copy this sector from a different bin or file, and you have commercial tools licensed to the PCM hardware, it might erase that data and so the software willl come up as unlicensed. So be careful if you need to preserve such a commercial license. If you did do a read-entire when you started (as recommended) you can restore it from that though.

Then there is clone which is all 3 segments. You'd do this when you want to backup your pcm and restore it to another one. For example if the hardware is faulty and you have junkyard pcm and you want to avoid having to relink the key and the bcm. Because it does all the segments you can transfer the PCMs entire identity to different hardware, or restore a backup you made.

Generally you'd use calibration flash for tuning or clone to get the OS and the settings. There isnt much reason why you'd only want to do specifically parameter blocks, but it is an option.

[Broke4speed]

Thank you very much for the info . Now I can start using the nice GUI 'write' button instead of digging into the 'tools' menu, which bugged me more than it should have. I just hate not knowing .