Sun-1

Sun Microsystems
Industry	Computer hardware, computer software
Founded	May 1982; 44 years ago
Founder	Andy Bechtolsheim
Products	Sun-1 workstations and servers

Sun-1 represented the inaugural series of UNIX computer workstations and servers developed by Sun Microsystems, debuting in May 1982. The architecture was founded on a CPU board created by Andy Bechtolsheim during his graduate studies at Stanford University, with financial support from DARPA. Operating on SunOS 0.9, a version of UniSoft's UniPlus V7 adaptation of Seventh Edition UNIX tailored for the Motorola 68000 microprocessor, the system initially lacked a graphical windowing environment. Early models sported a distinctive red bas relief badge displaying the word SUN formed by symbols resembling the letter U, which served as the original Sun emblem.

The first commercial sale of a Sun-1 workstation occurred in May 1982, with Solo Systems as the purchaser. The Sun-1/100 model gained recognition through its role in the original Lucasfilm EditDroid non-linear video editing system.

Models

Model	Chassis
Sun 100	Desktop chassis with 7-slot Multibus
Sun 150	Rackmount chassis featuring 15-slot Multibus

Hardware

The foundation of the Sun-1 workstation was the Stanford-engineered SUN workstation, designed by co-founder Andy Bechtolsheim, incorporating Multibus architecture for CPU, memory, and video display cards. The subsequent generation of these cards introduced a dedicated private memory bus, enabling expansion up to 2 MB without degrading performance.

Introduced in 1982, the Sun 68000 board was a robust single-board computer that integrated a 10 MHz Motorola 68000 CPU, a proprietary Sun-designed memory management unit (MMU), 256 KB zero wait state memory equipped with parity checking, up to 32 KB EPROM storage, two serial communication ports, a 16-bit parallel interface, and an Intel Multibus connection—all within a compact layout.

By combining the Motorola 68000 processor with an advanced MMU developed by Sun Microsystems, the CPU board facilitated multitasking under UNIX, supporting capabilities such as memory protection, code sharing, and demand paging. This custom MMU overcame several constraints present in the Motorola 68451 MMU.

Memory capacity started at 256 KB onboard and could be increased via two expansion cards to reach a total of 2 MB. These expansion modules conformed to the Multibus standard but accessed memory through a synchronous private "P2" bus to maintain zero wait state operation. Adding memory required disabling overlapping segments between onboard and expansion memory.

Integrated input/output included dual serial ports—initially utilizing Intel 8274 UARTs and later replaced by NEC D7201C chips—with Serial Port A configured as Data Circuit-terminating Equipment (DCE) featuring modem control signals and console functionality when no graphical display was attached. Serial Port B operated as Data Terminal Equipment (DTE) without modem control support. Both ports allowed terminal connections, facilitating multiple user sessions per workstation. The 16-bit parallel port connected specialized input devices such as keyboards and mice but was not intended for general printer use.

The CPU board employed a fully compatible asynchronous Multibus (IEEE 796) interface capable of supporting devices with diverse transfer speeds and multi-master direct memory access (DMA). It addressed up to 1 MB each of memory and I/O address spaces.

Input peripherals varied by region, including Micro Switch or KeyTronic keyboards. The graphics subsystem offered frame buffers capable of resolutions (displaying ), with hardware acceleration for raster graphic operations. Visual output utilized Ball Corporation HD17H 17-inch monitors. Initial Ethernet boards implemented Xerox PARC's 3 Mbit/s standard, subsequently upgraded to 3Com's faster 10 Mbit/s Ethernet. Disk controllers supported connections for up to four Fujitsu or CDC hard drives. All components were housed within either a six- or seven-slot Multibus card cage.

Subsequent releases featured color displays available in 13- or 19-inch sizes with frame buffers able to render at resolutions using a palette containing up to sixteen million colors. Magnetic tape storage options were expanded to include half-inch reel-to-reel and QIC-02 cartridge formats.

A second-generation CPU board for the Sun-1 platform, designated Sun-1.5, provided compatibility with UNIX System V Release 4.1c variants.

Sun-1 systems that received upgrades incorporating Sun-2 Multibus CPU boards were identified by adding a U suffix to their model numbers.

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