Atari TT030: Тарихы мен технологиясы

Personal computer by Atari

The Atari TT030 is a member of the Atari ST family, released in 1990. It was originally intended to be a high end Unix workstation, but 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 possesses 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.

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 is the first true "thirty two bit bus/thirty two bit instruction" chip from Motorola. Unlike the 68000 used in the original STs, the 68020 is capable of fetching a 32 bit value in one memory cycle, while the older STs need two cycles. The TT was initially designed around the 68020 CPU, but as the project progressed, Atari Corp. realized that the 68020 was not the best option for the TT. The 68020 still lacked some features offered by the next successor in the 68000 line, the new 68030. The new 68030 features built in memory management hardware that provide separate Supervisor, User, Program, and Data virtual memory spaces, and provides a 256 byte on chip data cache. 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) cannot handle anything over 16 MHz. Some software also has 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 runs at double that of the system bus speed. TOS 3.01 is the operating system that Atari bundled with the TT. It is a 512 KB ROM specifically designed for the TT. However, it does not feature pre emptive multitasking. Another variant, known as TT/X, uses Unix System V R4 and WISH (Motif extension). The TT030 was first introduced at CeBIT in Hannover, Germany and launched in 1990. It retailed for $2995 with 4 MB RAM and a 40 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, as well as the entire ST family. A number of TT machines were built as developer systems for the Jaguar.

The TT features a number of devices that had previously been unavailable for Atari Corp. systems. For example, an AppleTalk network port (there never was a driver for it, possibly due to license problems), VME expansion bus, new VGA video graphics modes, and a true SCSI port. Existing ST features such as MIDI ports, a cartridge port, and the ASCI/DMA port are retained in this system. One device that is left out is the BLiTTER graphics chip, which first appeared in the Atari Mega ST systems four to five years earlier. Using the existing 8 MHz chip would have only served to bottleneck the TT's performance. To be useful, a new 32 MHz blitter chip would have had to have been designed for the TT, however Atari chose not to do so. A developer system version of the TT was available, supplied with Atari System V (ASV), Atari's version of Unix System V Release 4, and the WISh2 windowing or graphical shell, a desktop environment running on OSF/Motif supplied by Non Standard Logics, as well as a collection of free software utilities including GCC. To support application development, the Atari System V software distribution included a library, AtariLib, to facilitate compliance with the Atari Style Guide, along with XFaceMaker 2, a graphical user interface builder for OSF/Motif, intended to assist in porting GEM based applications. Having evolved to become a System V Release 3.2 product, Atari delayed the release of ASV to target the more recent System V Release 4. A developer release of ASV was made available in November 1991, but a final release of ASV was not ready until mid 1992. However, by the end of that year, Atari Corp. had dropped all Unix development.