Atari TT030

Infobox computer
Photo =
Type = Personal computer
Released = 1990
Discontinued = 1993
Processor = Motorola 68030 32MHz
Memory = 2/16 MB
OS = Atari TOS 3.0x

The Atari TT030 is a 32-bit version of the 16/32-bit Atari ST family.

History

Atari Corporation realized that to remain competitive, they needed to begin taking steps to exploit the power offered by other processors in the Motorola 68000 series. At that time, the best option was the 68020. It was the first true "thirty-two bit bus/thirty-two bit instruction" chip from Motorola. Unlike the original 68000 used in the STs, the 68020 was capable of fetching a 32-bit value in one cycle, while the older STs took two cycles to fetch a 32-bit value.

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.

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 Hanover, Germany and launched in 1990. It retailed for $2995 with 2 MB RAM and 50 MB hard drive. The US release followed 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.

Details

The TT featured a number of devices that had previously been unavailable for Atari Corp. systems. For example, an Appletalk network port (unfortunately, there never was a driver for it, maybe due to license problems), VME expansion bus, new VGA video graphics modes, and a true SCSI port. Existing ST features such as MIDI ports, cartridge port, and the ASCI/DMA port were retained in this system.

One device that was left out was the BLiTTER graphics chip, which first appeared in the Atari Mega ST systems four to five years earlier. Apparently, Atari Corp. felt that the Motorola 68030 was enough power to drive the graphics, so one was not included.

A new version of TOS was developed for this system. An Atari Corp. version of Unix was also released (System V).

This machine marked Atari Corp.'s last big push into the workstation market. The MEGA STe and the Falcon030 were released after this system, but they weren't aimed at business quite the same way that this system was. The TT was doomed almost from the beginning. A 50 MHz 68030 was already on the market at the time, and the 68040 wasn't too far off. A 32 MHz Processor/16 MHz bus system just didn't sound powerful enough to the workstation market. Multitasking was the big buzz word in 1990/1991, and this system was not designed to handle it. Multitasking was offered by Atari Corp. in 1993, with the release of Multi-TOS. This multitasking version of TOS took advantage of the TT's MMU, which offered multitasking as well as memory protection.

Another problem was that Atari Corp. didn't release Unix for the TT until mid-1992. By the end of that year, Atari Corp. dropped all Unix development.A special version of the TT was designed to be a UNIX station, called TT/X it was supplied with UNIX System V R4 and WISH (an extension of OSF Motif).

Technical specifications

All TTs were made up of both custom and commercial chips:

*Custom chips
**TT Shifter "TT Video shift register chip" — Enabled bitmap graphics. Featured a 64-bit wide bus with interleaved access to ("dual purpose") system memory and on-chip buffers for high bandwidths. Contiguous 32 KB memory for ST modes, 154 KB for TT modes.
**TT GLU "Generalized Logic Unit" — Control logic for the system used to connect the STs chips. Not part of the data path, but needed to bridge chips with each other. Used in TT and MEGA STE.
**DMA "Direct Memory Access" — Three independent channels, one for floppy and hard drive data transfers, one for the SCSI port and one for 85C30 SCC network port. Direct access to ("dual purpose") system memory in the ST. 2 chips used.
**MCU "Memory Control Unit" — For system RAM.
*Support chips
**MC6850P ACIA "Asynchronous Common Interface Adapter" — Enabled the ST to directly communicate with MIDI devices and keyboard (2 chips used). 31.25 kBaud for MIDI, 7812.5 bit/s for keyboard.
**MC68901 MFP "Multi Function Peripheral" — Used as an interrupt controller, timers and RS232C ports (2 chips used).
**NCR 5380 "SCSI Controller" — 8-bit asynchronous transfers up to 4 MB/s.
**WD-1772-PH "Western Digital Floppy Disk Controller" — Floppy controller chip.
**Zilog 85C30 SCC "Zilog Serial Communications Controller" — Two high-speed SDLC serial ports.
**YM2149F PSG "Programmable Sound Generator" — Provided 3-voice sound synthesis, also used for floppy signalling and printer port.
**HD6301V1 "Hitachi keyboard processor" — Used for keyboard scanning and mouse/joystick ports.
**MC146818A "Motorola Real Time Clock"

*CPU: Motorola 68030 @ 32 MHz (system bus @ 16 MHz)
*FPU: Motorola 68882 @ 32 MHz
*RAM:
**System RAM ("dual purpose") 2 MB ST RAM expandable to 12 MB
**TT RAM ("single purpose") expandable to 256 MB TT RAM on daughter board using either 30-pin or 72-pin SIMMs
*Sound: Yamaha YM2149 + National LMC 1992, same as in STe
*Drive: 1.44 MB (later version) or 720 KB (first TT version) 3½" floppy disk drive
*Ports:
** MIDI In/Out
**3 x RS-232
** Serial LAN RS-422
** Printer
** VGA Monitor (analog RGB and Mono)
** Extra Disk drive port
** ACSI and SCSI port
** VMEbus inside case
** cartridge (128 KB)
** keyboard (detachable)
*** Joystick and Mouse ports (on keyboard)
*Operating System:
** NetBSD
** TOS ("The Operating System") with the Graphical Environment Manager (GEM) graphical user interface (GUI) TOS versions: 3.01, 3.05 or 3.06 in ROM. Four socketed 1 Mb ROMs providing 512 KB of ROM space.
*Display modes:
**Color: 320×200 (16 color), 320×480 (256 colors), 640×200 (4 colors), 640×480 (16 colors), palette of 4096 colors
**Duochrome: 640×400 (2 colors)
**Monochrome: 1280×960 mono TT high with special 19 in (483 mm) monitor
*Case: Two-piece desktop-style.
*Release Date: 1990-1991

The (at least) two versions of the TT can be distinguished by:

*Internal sheet plate (old) or coating (new) for electromagnetic compatibility
*CPU and FPU on daughter board (old) or directly on main board (new)
*1.44 MB HD floppy drive (720 KB DD floppy drive on older models)

External links

* [http://pagesperso-orange.fr/gtello/tt_e.htm Guillaume Tello's WEB page] What to do with a TT? Some hardware expansions detailed
* [http://pagesperso-orange.fr/gtello/downld_e.htm Download page] Programs for Atari, mostly for the TT.