Symbolics

Symbolics 3640

Symbolics 3600 Front Panel

Symbolics Boards

In 1983, a year later than planned, Symbolics introduced the 3600 family of Lisp machines. Code-named the "L-machine" internally, the 3600 family was an innovative new design, inspired by the CADR architecture but sharing few of its implementation details. The main processor had a 36-bit word (divided up as 4 or 8 bits of tags, and 32 bits of data or 28 bits of memory address). Memory words were 44 bits, the additional 8 bits being used for error-correcting code (ECC). The instruction set was that of a stack machine. The 3600 architecture provided 4,096 hardware registers, of which half were used as a cache for the top of the control stack; the rest were used by the microcode and time-critical routines of the operating system and Lisp run-time environment. Hardware support was provided for virtual memory, which was common for machines in its class, and for garbage collection, which was unique.

The original 3600 processor was a microprogrammed design like the CADR, and was built on several large circuit boards from standard TTL integrated circuits, both features being common for commercial computers in its class at the time. Central processing unit (CPU) clock speed varied depending on which instruction was being executed, but was typically around 5 MHz. Many Lisp primitives could be executed in a single clock cycle. Disk input/output (I/O) was handled by multitasking at the microcode level. A 68000 processor (termed the front-end processor, (FEP)) started the main computer up, and handled the slower peripherals during normal operation. An Ethernet interface was standard equipment, replacing the Chaosnet interface of the LM-2.

The 3600 was roughly the size of a household refrigerator. This was partly due to the size of the processor (the cards were widely spaced to allow wire-wrap prototype cards to fit without interference) and partly due to the size of disk drive technology in the early 1980s. At the 3600's introduction, the smallest disk that could support the ZetaLisp software was 14 inches (360 mm) wide (most 3600s shipped with the 10½-inch Fujitsu Eagle). The 3670 and 3675 were slightly shorter in height, but were essentially the same machine packed a little tighter. The advent of 8 inches (200 mm), and later 5+1⁄4 inches (130 mm), disk drives that could hold hundreds of megabytes led to the introduction of the 3640 and 3645, which were roughly the size of a two-drawer file cabinet.

Later versions of the 3600 architecture were implemented on custom integrated circuits, reducing the five cards of the original processor design to two, at a large manufacturing cost savings and with performance slightly better than the old design. The 3650, first of the G machines, as they were known within the company, was housed in a cabinet derived from the 3640s. Denser memory and smaller disk drives enabled the introduction of the 3620, about the size of a modern full-size tower PC. The 3630 was a fat 3620 with room for more memory and video interface cards. The 3610 was a lower priced variant of the 3620, essentially identical in every way except that it was licensed for application deployment rather than general development.

Symbolics Keyboard

The various models of the 3600 family were popular for artificial intelligence (AI) research and commercial applications throughout the 1980s. The AI commercialization boom of the 1980s led directly to Symbolics' success during the decade. Symbolics computers were widely believed to be the best platform available for developing AI software. The LM-2 used a Symbolics-branded version of the complex space-cadet keyboard,[8] while later models used a simplified version (at right), known simply as the Symbolics keyboard.[9] The Symbolics keyboard featured the many modifier keys used in Zmacs, notably Control/Meta/Super/Hyper in a block, but did not feature the complex symbol set of the space-cadet keyboard.

Also contributing to the 3600 series' success was a line of bit-mapped graphics color video interfaces, combined with extremely powerful animation software. Symbolics' Graphics Division, headquartered in Westwood, Los Angeles, California, near to the major Hollywood movie and television studios, made its S-Render and S-Paint software into industry leaders in the animation business.

Symbolics developed the first workstations able to process high-definition television (HDTV) quality video, which enjoyed a popular following in Japan. A 3600, with the standard black-and-white monitor, made a cameo appearance in the movie Real Genius. The company was also referenced in Michael Crichton's novel Jurassic Park.

Symbolics' Graphics Division was sold to Nichimen Trading Company in the early 1990s, and the S-Graphics software suite (S-Paint, S-Geometry, S-Dynamics, S-Render) ported to Franz Allegro Common Lisp on Silicon Graphics (SGI) and PC computers running Windows NT. Today it is sold as Mirai by Izware LLC, and continues to be used in major motion pictures (most famously in New Line Cinema's The Lord of the Rings), video games, and military simulations.

3600 ports, with Connection Machine interface

Symbolics' 3600-series computers were also used as the first front end controller computers for the Connection Machine massively parallel computers manufactured by Thinking Machines Corporation, another MIT spinoff based in Cambridge, Massachusetts. The Connection Machine ran a parallel variant of Lisp and, initially, was used primarily by the AI community, so the Symbolics Lisp machine was a particularly good fit as a front-end machine.

For a long time, the operating system didn't have a name, but was finally named Genera around 1984. The system included several advanced dialects of Lisp. Its heritage was Maclisp on the PDP-10, but it included more data types, and multiple-inheritance object-oriented programming features. This Lisp dialect was called Lisp Machine Lisp at MIT. Symbolics used the name ZetaLisp. Symbolics later wrote new software in Symbolics Common Lisp, its version of the Common Lisp standard.

In the late 1980s (2 years later than planned), the Ivory family of single-chip Lisp Machine processors superseded the G-Machine 3650, 3620, and 3630 systems. The Ivory 390k transistor VLSI implementation designed in Symbolics Common Lisp using NS, a custom Symbolics Hardware Design Language (HDL), addressed a 40-bit word (8 bits tag, 32 bits data/address). Since it only addressed full words and not bytes or half-words, this allowed addressing of 4 Gigawords (GW) or 16 gigabytes (GB) of memory; the increase in address space reflected the growth of programs and data as semiconductor memory and disk space became cheaper. The Ivory processor had 8 bits of ECC attached to each word, so each word fetched from external memory to the chip was actually 48 bits wide. Each Ivory instruction was 18 bits wide and two instructions plus a 2-bit CDR code and 2-bit Data Type were in each instruction word fetched from memory. Fetching two instruction words at a time from memory enhanced the Ivory's performance. Unlike the 3600's microprogrammed architecture, the Ivory instruction set was still microcoded, but was stored in a 1200 × 180-bit ROM inside the Ivory chip. The initial Ivory processors were fabricated by VLSI Technology Inc in San Jose, California, on a 2 µm CMOS process, with later generations fabricated by Hewlett-Packard in Corvallis, Oregon, on 1.25 µm and 1 µm CMOS processes. The Ivory had a stack architecture and operated a 4-stage pipeline: Fetch, Decode, Execute and Write Back. Ivory processors were marketed in stand-alone Lisp Machines (the XL400, XL1200, and XL1201), headless Lisp Machines (NXP1000), and on add-in cards for Sun Microsystems (UX400, UX1200) and Apple Macintosh (MacIvory I, II, III) computers. The Lisp Machines with Ivory processors operated at speeds that were between two and six times faster than a 3600 depending on the model and the revision of the Ivory chip.

The Ivory instruction set was later emulated in software for microprocessors implementing the 64-bit Alpha architecture. The "Virtual Lisp Machine" emulator, combined with the operating system and software development environment from the XL machines, is sold as Open Genera.

Sunstone was a processor similar to a reduced instruction set computer (RISC), that was to be released shortly after the Ivory. It was designed by Ron Lebel's group at the Symbolics Westwood office. However, the project was canceled the day it was supposed to tape out.

As quickly as the commercial AI boom of the mid-1980s had propelled Symbolics to success, the AI Winter of the late 1980s and early 1990s, combined with the slowdown of the Ronald Reagan administration's Strategic Defense Initiative, popularly termed Star Wars, missile defense program, for which the Defense Advanced Research Projects Agency (DARPA) had invested heavily in AI solutions, severely damaged Symbolics. An internal war between Noftsker and the CEO the board had hired in 1986, Brian Sear, over whether to follow Sun's suggested lead and focus on selling their software, or to re-emphasize their superior hardware, and the ensuing lack of focus when both Noftsker and Sear were fired from the company caused sales to plummet. This, combined with some ill-advised real estate deals by company management during the boom years (they had entered into large long-term lease obligations in California), drove Symbolics into bankruptcy. Rapid evolution in mass market microprocessor technology (the PC revolution), advances in Lisp compiler technology, and the economics of manufacturing custom microprocessors severely diminished the commercial advantages of purpose-built Lisp machines. By 1995, the Lisp machine era had ended, and with it Symbolics' hopes for success.

Symbolics continued as an enterprise with very limited revenues, supported mainly by service contracts on the remaining MacIvory, UX-1200, UX-1201, and other machines still used by commercial customers. Symbolics also sold Virtual Lisp Machine (VLM) software for DEC, Compaq, and HP Alpha-based workstations (AlphaStation) and servers (AlphaServer), refurbished MacIvory IIs, and Symbolics keyboards.

In July 2005, Symbolics closed its Chatsworth, California, maintenance facility. The reclusive owner of the company, Andrew Topping, died that same year. The current legal status of Symbolics software is uncertain.[10] An assortment of Symbolics hardware was still available for purchase as of August 2007.[11] In 2011, the United States Department of Defense (US DoD) awarded Symbolics a 5 year contract for maintenance work, ending in September 2016.[12]

On March 15, 1985, symbolics.com became the first (and currently, since it is still registered, the oldest) registered .com domain of the Internet.[13] The symbolics.com domain was purchased by XF.com in 2009.

This software was also used to create a few computer-animated movies and was used for some popular movies.

• 1984, graphics for the little screens on the bridges of the Enterprise and the Klingon ship in Star Trek III: The Search for Spock
• 1985, 3D animations for Real Genius
• 1987, Symbolics, Stanley and Stella in: Breaking the Ice
• 1989, Symbolics, The Little Death
• 1990, Symbolics, Ductile Flow, presented at SIGGRAPH 1990
• 1990, 3D animations for Jetsons: The Movie
• 1990, 3D animations for The Funtastic World of Hanna-Barbera
• 1991, Symbolics, Virtually Yours
• 1991, 3D animations for An American Tail: Fievel Goes West
• 1993, 3D animation of the Orca for Free Willy