There are two factors involved here. The first is the memory limitation in the module, and the second is the way signals are compressed for storage in the module. As originally shipped, the AVG1 and DVG1 modules each have about 256 K of memory. This limits the number of signal that can be stored to a level of about 30-40 signals, depending on the format, number of unique lines, and the complexity of the signal. About a year after initial shipments, the memory in the modules was quadrupled. Modules with version 2.0 have the increased memory capability, and earlier modules can be upgraded using 040-1548-00 upgrade kit. One kit is required for each module to be updated. These updated modules will have a version 1.1 for AVG1 and 1.2 for DVG1. There are three possible modes for compiling signals for the TG2000. The maximum compression mode allow more signals to be stored, at the price of download time. Two stages of compression are used. No compression mode allow the signals to be stored uncompressed, which results in faster download times, but less signal storage. Normal mode is a compromise to these two modes. A single compression stage is used.