Merdofon and chiptunes

[Bryce]

Most cars, even the most modern, still have their performance settings in an EPROM. In older cars it was a stand-alone EPROM, in modern cars it's usually ROM within the micro-processor. The manufacturers program this through a connection called OBD-II (On Board Diagnositics V2). Which has a serial connection and (since version 2) a two wire digital connection called CAN (Controller Area Network). For chiptuners, programming through the CAN-Bus isn't easy because there are security layers to get through, so they usually dis-mantle the box and access the µP pins directly and use a standard programmer. The only difficult bit about this, is that the IC is always soldered in, no socket, so it has to be done on the PCB. The actual image they burn is rarely developed by themselves, they buy this from tuning companies that modify cars for the racing industry. I'm not sure what they pay for the images, but the €300 has to cover the time to dis-mantle / re-assemble the box, the programming tools and the images they bought, but they probably make a healthy profit anyway

Bryce.

[Gryzor]

So - wait, if you upload a chiptune to the car's ROM what happens? Does it start dancing to the music? Is it different if the chiptune comes from different systems?

[Bryce]

Yeah, if it's a SID chiptune, the car turns grey/brown and goes slower than before.

But really. The car "tune" is a look-up table of values or algorythm that tells the engine controller how much Air/petrol mix to use depending on accelerator position / certain engine sensor inputs. By changing these values (making the curve steeper) you can get more horsepower out of the engine (and use a lot more fuel in the process). The table is unique to each car/engine, so you can't just upload any old file. And messing around with the values, when you don't know what you're doing will most likely end up either with an engine that doesn't run at all or one that destroys itself after a few days.

Bryce.

[Gryzor]

Yes, but in these few short, sweet days...