USR used an incompatible set of -prefixed commands, Microcom used , and Telebit was based on setting a series of registers. All of these survived for some time into the early 1990s. Through the late 1980s and early 1990s, new standard high-speed modes were introduced by the CCITT. The first of these, v.32, offered 9600 bit/s in both directions at the same time, whereas earlier high-speed protocols were high-speed in one direction only. In 1988 Hayes effectively abandoned their Express 96 protocol in favor of v.32, which along with MNP support was built into the US$1199 Hayes V-series Smartmodem 9600. In 1990 the company introduced the Smartmodem Ultra 96, which offered both v.32 and Express 96 support, and added the new v.42bis error correction and compression system (in addition to MNP). v.32 modems remained fairly rare and expensive, although by 1990 third-party v.32 modems were available for approximately US$600. V.32bis Almost immediately after the introduction of V.32, the CCITT began the process of standardizing a slightly faster variant, the 14,400 bit/s V.32bis. During previous speed bumps, the large companies like Hayes and USR were generally the first to respond with new models. Not so in this case; shortly after V.32bis was ratified in 1991, Rockwell introduced a low-cost chipset supporting the new standard, along with similar V.32 and V.22bis (2400 bit/s) versions, all of which supported MNP, V.42bis and, optionally, 9600 bit/s V.29 fax modem capabilities. Their system was introduced commercially in the SupraFAXModem 14400, which went on to become a runaway bestseller. Soon there were hundreds of similar models on the market, and Rockwell's competitors also rushed in with similar chipsets of their own. Hayes was never able to re-establish itself as a market leader through this period. In the fall of 1991 they introduced the US$799 Smartmodem Ultra 144 which also supported Express 96, but by this point, Express 96 had little cachet and the market was already flooded with lower-cost modems. They then split their line into the Accura and Optima brands, offering the Accura as a low-cost model, although the feature sets were not that different between the two lines. Hayes eventually purchased two of their competitors, Practical Peripherals and Cardinal, turning them into low-cost brands in order to compete with a flood of companies like Supra and Zoom Telephonics. As speeds increased with the introduction of V.34 and V.90, Hayes increasingly became a follower rather