The Scanmaster is the most common. It is a firmware monitor that may be mounted on the dash or top of the radio pod. It is more a monitor than a recording version of the scantools. Some, that are software based for laptops, actually record and play back data have a lot more function but have to be plugged into the aldl port each time you use them.
The Scanmaster is good for setting the tps, iacs, monitoring timing retard, and being able to see all the various sensors that the ECM uses for operating the engine.
It may be obtained from most vendors, Cotton, Ramchargers, etc.
Here is a chart on the TurboLink site which is one of the laptop based systems. This chart gives a comparison between the systems. It is a really neat, user friendly system with great support. I have a couple of Scanmasters, Turbolink, and Direct Scan. I use the Scanmaster mainly for checking settings and monitoring timing retard. I use the others for troubleshooting..nice to be able to record data and play it back to see what happened when you were going down the road.