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The Atari TT030 is a member of the Atari ST family, originally intended to be a high end Unix workstation, however Atari took two years to release a port of Unix SVR4 for the TT, which prevented the TT from ever being seriously considered in its intended market. In 1992 the TT was replaced by the Atari Falcon, a low cost consumer oriented machine with greatly improved graphics and sound capability, but with a slower and severely bottle-necked CPU. The Falcon possessed only a fraction of the TT's raw CPU performance. Though well priced for a workstation machine, the TT's high cost kept it mostly out of reach of the existing Atari ST market until after the TT was discontinued and sold at discount. The nascent open source movement eventually filled the void. Thanks to open hardware documentation, the Atari TT, along with the Amiga and Atari Falcon, were the first non-Intel machines to have Linux ported to them, though this work did not stabilize until after the TT had already been discontinued by Atari. By 1995 NetBSD had also been ported to the Atari TT. ==History== Atari Corporation realized that to remain competitive as a computer manufacturer, they needed to begin taking steps to exploit the power offered by more advanced processors in the Motorola 68000 series. At that time, the highest performance member was the 68020. It was the first true "thirty-two bit bus/thirty-two bit instruction" chip from Motorola. Unlike the 68000 used in the original STs, the 68020 was capable of fetching a 32-bit value in one cycle, while the older STs took two. The TT was initially designed around the 68020 CPU, however as the project progressed, Atari Corp. realized that the 68020 was not the best option for the TT. The 68020 still lacked certain important features offered by the next successor in the 68000 line, the new 68030. The new 68030 featured a full 32-bit address/data bus and internal registers; separate Supervisor, User, Program, and Data virtual memory spaces; built-in memory-management hardware; and 256-byte on-chip instruction and data caches. When the decision was made to switch from a 68020 to a 68030 CPU, it presented a whole new set of problems. The original specifications for the TT's clock speed was 16 MHz, which was selected to maintain backward compatibility. The existing ST chips used in the TT (DMA and video chips for example) could not handle anything over 16 MHz. Some software also had problems running at faster speeds. To make the system work with a 32 MHz 68030, Atari Corp. had to scale back their plans somewhat, and add a large amount of cache to the system. As a result, the processor runs at 32 MHz, while the system bus runs at 16 MHz. This is similar to the tactic employed by Apple with the ill-fated Macintosh IIvx and later employed by makers of PCs with an Intel 80486DX2 CPU which ran at double that of the system bus speed. TOS 3.01 was the operating system that came with the Atari TT. It was a 512 kB ROM specifically designed for the TT. However, it did not feature pre-emptive multitasking. Another variant, known as TT/X, used Unix System V R4 and WISH (motif extension). The TT030 was first introduced at CeBIT in Hannover, Germany〔(The Power of a Workstation ), The New Atari TT Computer, August 1989, Atari Corporation〕〔(Sub: The Atari TT: 68030 ), ''Atari has announced its new TT 68030 based Computer at COMDEX and Hannover in recent months.'', Topic 35, Sat June 10, 1989, R.MOYER1, Atari Roundtables (BBS)on GEnie〕〔(The Future of Atari Computing:TT and STE Unveiled in Germany ), By Andrew Reese, Start Editor, Start Vol. 4 No. 5 / December 1989 / p. 14〕 and launched in 1990. It retailed for $2995 with 2 MB RAM and a 50 MB hard drive. The US release came the following year. In 1993, Atari Corp.'s exit from the computer business marked the end of the TT. A number of TT machines were built as developer systems for Jaguar. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Atari TT030」の詳細全文を読む スポンサード リンク
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