developers have noted that "there is still reference of the tape and some hardware addresses" and an updated vintage Epyx manual describes the bare existence of what could be utilized for tape support. A 2009 retrospective interview with Mical clarifies that there is no truth to some early reports claiming that games were loaded from tape, and elaborates, "We did think about hard disk a little." The networking system was originally developed to run over infrared links and codenamed RedEye. This was changed to a cable-based networking system before the final release as the infrared beam was too easily interrupted when players walked through the beam, according to Peter Engelbrite. Engelbrite developed the first recordable eight-player co-op game, and the only eight-player game for the Lynx, Todd's Adventures in Slime World. Atari changed the internal speaker and removed the thumb stick on the control pad. At Summer 1989 CES, Atari's press demonstration included the "Portable Color Entertainment System", which was changed to "Lynx" when distributed to resellers, initially retailing in the US at . Its launch was successful. Atari reported that it had sold 90% of the 50,000 units shipped in the launch month in the U.S. with a limited launch in New York. US sales in 1990 were approximately 500,000 units according to the Associated Press. In late 1991, it was reported that Atari sales estimates were about 800,000, which Atari claimed was within its expected projections. Lifetime sales by 1995 amount to fewer than 7 million units when combined with the Game Gear. In comparison, 16 million Game Boy units were sold by 1995 because of its ruggedness, half price, much longer battery life, bundling with the smash hit Tetris, and superior game library. As with the console units, the game cartridge design evolved over the first year of the console's release. The first generation of cartridges are flat, and designed to be stackable for ease of storage. However, this design proved to be very difficult to remove from the console and was replaced by a second design. This style, called "tabbed" or "ridged", adds two small tabs on the underside to aid in removal. The original flat style cartridges can be stacked on top of the newer cartridges, but the newer cartridges can not be easily stacked on each other, nor were they stored easily. Thus a third style, the "curved lip" style was produced, and all