Don't get me wrong, there's nothing wrong with the "red Brick" scanner for touble shooting. You're not trying to "tune" it, you're looking for anomalies in the data stream. Programs like TunerPro Rt were designed to break down the actual hexadecimal code with the tuner in mind. GM really didn't want anyone to be able to see what's going on in the backgraound, it took a bunch of "hackers" to unlock the key. The 1227747 is probably the most hacked with the most support of any other ECM/PCM. Bobr@ dynamicefi.com even took these early ECMs, sped up their baud rate from 160 to 8192, added flash (8 different banks) and auto tune capabilities with almost (1 or a couple pin moves) plug-n-play connectivity to your wiring harnesses. If you're not interested in tuning, scanners like his, or newer ones (more expensive) are the way to go.