The TI-92 was originally released in 1995, and was the first symbolic calculator made by Texas Instruments. It came with a computer algebra system (CAS) based on Derive, geometry based on Cabri II, and was one of the first calculators to offer 3D graphing. The TI-92 was not allowed on most standardized tests due mostly to its QWERTY keyboard. Its larger size was also rather cumbersome compared to other graphing calculators. In response to these concerns, Texas Instruments introduced the TI-89 which is functionally similar to the original TI-92, but featured Flash ROM and 188 KB RAM, and a smaller design without the QWERTY keyboard. The TI-92 was then replaced by the TI-92 Plus, which was essentially a TI-89 with the larger QWERTY keyboard design of the TI-92. Eventually, TI released the Voyage 200, which is a smaller, lighter version of the TI-92 Plus with more Flash ROM. The TI-92 is no longer sold through TI or its dealers, and is very hard to come by in stores.