The SPARCstation 20
(a.k.a. SS20, codename Kodiak) is a Sun Microsystems workstation
based on the SuperSPARC
CPU. It was the last model in the SPARCstation
family of Sun "pizza box
" computers, which was superseded by the UltraSPARC
design in 1995.
The SPARCstation 20 had dual 50 MHz MBus ports that allowed it to use faster CPUs than the SPARCstation 10. With two dual-CPU modules and updated firmware, the SPARCstation 20 supported a maximum of 4 CPUs. The fastest CPU produced for the SPARCstation 20 was the 200 MHz Ross hyperSPARC.
The PROM in the SPARCstation 20 determines CPU compatibility. Version 2.25r was the last PROM release for the SPARCstation 20.
The SPARCstation 20 has 8 200-pin DSIMM
slots, and supports a maximum of 512 MB of memory with 64 MB modules. Memory modules for the SPARCstation 20 are compatible with the SPARCstation 10
, Sun Ultra 1
, and other computers in the sun4m
family, but they are physically incompatible with the SIMM slots found in PC computers
2 of the 8 SIMM slots are wider than the others and can be used with non-memory peripherals like caching NVSIMM and video VSIMM cards.
The SPARCstation 20 has two internal SCA bays, an external SCSI connector, and two bays for CD-ROM or floppy drives. The CD-ROM and floppy bays are slightly shorter than a standard 3.5" bay and regular devices intended for PC compatible computers do not usually fit.
The SCSI host controller is integrated with the motherboard. The SPARCstation 20 does not support IDE devices.
A limitation in all releases of the OpenBoot PROM for the SPARCstation 20 prevents it from booting from a filesystem larger than 2 gigabytes.
The SPARCstation 20 has one integrated AMD Lance 10baseT Ethernet
interface. Additional Ethernet interfaces can be added with an SBus
The SPARCstation 20 has a builtin AVB (13W3
video) socket driven by an optional SX (CG14) framebuffer
, capable of up to 1280x1024 (8MB) or 1152x900 (4MB) in 24-bit color. Alternatively, SBus cards can be used, including the ZX (Leo), Turbo GX (CG6) and others.
The SPARCstation 20 has integrated sound with 4 standard 3.5 mm audio jacks for headphones, microphone, line in, and line out.
The SPARCstation 20 uses NVRAM to hold data about the system, such as the serial number and MAC address. If the battery on the chip dies, then the NVRAM must be reset.
4.1.3_U1B onwards, Solaris
2.3 to 9, Linux (Debian, Gentoo, SuSE 7.0 - 7.3, probably others), MirBSD, NetBSD
run on the SPARCstation 20. On certain CPU modules (Sun SuperSPARC only), NeXTSTEP
3.3 and OPENSTEP
4.x also run..