Sun-2
| Industry | Computer hardware |
|---|---|
| Founded | November 1983 |
| Products | Sun-2 UNIX workstations and servers |
The Sun-2 lineup of UNIX workstations and servers was introduced by Sun Microsystems in November 1983. Serving as the successor to the initial Sun-1 series, the Sun-2 incorporated a 10 MHz Motorola 68010 CPU combined with a custom Sun-2 Memory Management Unit (MMU). This design facilitated the debut of a complete virtual memory UNIX system, operating on SunOS 1.0, which was based on 4.1BSD. Initial variants utilized the Intel Multibus framework, while subsequent models transitioned to the VMEbus standard—a bus architecture that was retained in later Sun product lines such as the Sun-3 and Sun-4.
Support for Sun-2 hardware persisted in SunOS through version 4.0.3.
In January 2001, efforts began to port Multibus-based Sun-2 machines to NetBSD, building upon existing compatibility with Sun-3 systems introduced in NetBSD 1.5. By April 2001, related support code started integration into the NetBSD source repository, and as of NetBSD 7.0.1, the sun2 platform is designated as tier 2.
Sun-2 models
The following table enumerates models in approximate order of release.
| Model | CPU board | Display | Maximum RAM | Chassis |
|---|---|---|---|---|
| 2/120 | Sun-2 Multibus or Sun-2 Multibus Prime | Monochrome | 8 MB | 9-slot Multibus (deskside) |
| 2/170 | Sun-2 Multibus or Sun-2 Multibus Prime | Optional | 8 MB | 15-slot Multibus (rackmount) |
| 2/50 | Sun 2050 VME | Monochrome | 8 MB | 2-slot VME (desktop) |
| 2/130 | Sun 2050 VME | Monochrome | 8 MB | 12-slot VME (deskside) |
| 2/160 | Sun 2050 VME | Color | 8 MB | 12-slot VME (deskside) |
A desktop disk and tape subsystem, colloquially known as the "Sun Shoebox," was introduced for the Sun-2/50 workstation. It accommodated a 5¼" disk drive and tape drive featuring proprietary DD-50 SCSI connectors specific to Sun.
Upgraded Sun-1 systems equipped with Sun-2 Multibus CPU boards were identified as 2/100U or 2/150U.
Typical pricing in the United States circa 1986 included: a monochrome 2/120 with 4 MB RAM, a 71 MB SCSI hard drive, and a 20 MB tape drive priced at $29,300; a color configuration of the 2/160 with 8 MB RAM, two 71 MB disks, and a 60 MB tape at $48,800; and a rackmount server model 2/170 featuring 4 MB memory, dual Fujitsu Eagle disks of 380 MB each, an SMD disk controller, tape drive, and rack mount for $79,500.
Sun-2 Multibus systems
The Sun 2/120 (9-slot deskside) and the rackmount-oriented 2/170 (15-slot) utilized the Multibus architecture. Their CPU boards incorporated a Motorola 68010 processor clocked at 10 MHz alongside a proprietary Sun MMU capable of addressing up to 8 MB of physical memory and supporting a virtual memory space of up to 16 MB. The uppermost megabyte of physical memory was allocated for the monochrome frame buffer. These CPU boards provided interfaces for the Sun-1 parallel keyboard and mouse as well as two serial communication ports.
Sun-2 VMEbus systems
Models such as the desktop-oriented Sun 2/50 (with a two-slot chassis), the monochrome desk-side Sun 2/130 (12-slot), and the color-equipped desk-side Sun 2/160 (also with a twelve-slot chassis) employed quad-depth, triple-height Eurocard CPU boards compatible with VMEbus. These boards were derived from the original Multibus CPU design and came equipped with either 2 MB or 4 MB of onboard memory, integrated monochrome frame buffers for the Sun-2 series, and built-in support for Thick Ethernet operating at 10 Mbit/s.
Memory expansion options included Sun's own offerings: a single-board Multibus memory module with 1 MB capacity and VMEbus modules available in either one or four megabytes. Additionally, third-party vendors like Helios Systems manufactured compatible memory boards providing up to four megabytes.
For video output, a frequently used option was the Sun-2 Prime Monochrome Video board delivering an image resolution of 1152x900 pixels in monochrome mode with TTL or ECL signaling standards; it also featured ports for keyboard and mouse connections while occupying the topmost megabyte of physical address space. The color variant—the Sun-2 Color Video board—offered an identical resolution but supported an eight-bit color palette utilizing four megabytes at the top of addressable memory.
Storage typically consisted of Modified Frequency Modulation (MFM) hard drives around 42 MB connected through an Adaptec MFM/SCSI host adapter on the Multibus backplane that also provided two serial ports. For larger capacity requirements, Storage Module Device (SMD) drives ranging from 65 to 380 MB were employed using Xylogics model 450 controllers capable of managing up to four disks simultaneously—though official support was limited to two drives by Sun Microsystems. Backup solutions included Quarter Inch Cartridge (QIC) tape drives with capacities near twenty megabytes connected via Archive Corporation QIC/SCSI converters and half-inch tape drives interfaced through Computer Products Corporation TAPEMASTER or Xylogics model 472 controller boards.
Ethernet networking was facilitated by either a Sun-designed board based on Intel’s i82586 chipset or by third-party hardware such as the 3Com model 3c400 network adapter. This enabled diskless operation for client machines like the Sun-2/50 over Ethernet connections.
Additional Multibus expansion boards supported by these systems included Sky Computer’s Floating Point Processor accelerator, the Sun Asynchronous Line Multiplexer (ALM) offering eight serial ports, and the SunLink Communications Processor (SCP) designed for integration with SNA and X.25 network protocols.
Reception
In its August 1984 issue, BYTE magazine characterized the Sun-2/120 as a machine comparable to the VAX class, highlighting its outstanding graphics capabilities and swift response times even under heavy workloads.