or 8 MB capacity, capable of up to (4 MB) or (8 MB) in 24-bit color. If two VSIMMs are installed, an auxiliary video board must also be installed to provide a second 13W3 video socket. Alternatively, SBus cards can be used, including the 8-bit color Turbo GX (CG6), 24-bit color ZX (Leo) and others. Sound The SPARCstation 20 has integrated sound with four standard 3.5 mm audio jacks for headphones, microphone, line in, and line out. NVRAM The SPARCstation 20 uses a battery-backed NVRAM module to hold data about the system, such as the host ID (serial number) and MAC address. If the battery on the chip dies, then the NVRAM module must be replaced (or modified to use an external battery), and the NVRAM must be reprogrammed with a MAC address and host ID. Optionally a M48T08-100PC1 can be used. Operating systems SunOS 4.1.3_U1B onwards Solaris 2.3 to 9 Linux (Debian, Gentoo, SuSE 7.0 - 7.3, probably others) NetBSD OpenBSD (up to 5.9) MirOS BSD NeXTSTEP 3.3 and OPENSTEP 4.x (SuperSPARC CPU modules only) Notable uses 117 SPARCstation 20 Model HS11 units, 87 with two 100 MHz hyperSPARC processors and 30 with four 100 MHz hyperSPARC processors, plus a single octo-processor SPARCserver 1000 were used to render Toy Story. Related computers SPARCstation 5 SPARCstation 10 See also SPARCstation External links FAQABOSS for old Sun computers The Rough Guide to MBus Modules (A list of CPU modules for the SPARCstation 20.) Vendor documentation SPARCstation 20 System Configuration Guide SPARCstation 20 Service Manual Sun4m Boot PROM Revisions Sun NVSIMM installation guide References Sun workstations SPARC microprocessor products