Sun Microsystems SPARCstation 20, Service Manual

Page: 184 / 266

160 SPARCstation 20 Service Manual • July 1996
FIGURE 11-21
DSIMM, Back View
VSIMM
SPARCstation 20 systems with the SX graphics option are equipped with a minimum
of 4 Mbytes of video random access memory (VRAM). Physically, VRAM chips are
grouped together as VSIMMs.
Each VSIMM contains 4 or 8 Mbytes of video memory. Each VSIMM is a complete
high-speed, high-resolution frame buffer that plugs into a memory slot located on
the system board. A maximum of two VSIMMs may be installed. With two VSIMMs
installed, a maximum of six DSIMMs (384 Mbytes) may be installed.
Note –
If a second VSIMM is installed, an auxiliary video board (AVB) must also be
installed to provide a second 13W3 video output connector. See “Auxiliary Video
Board” on page 168.
A VSIMM differs in appearance from a DSIMM.
FIGURE 11-22
shows the front view of
a VSIMM.
FIGURE 11-23
shows the back view of a VSIMM.
FIGURE 11-22
VSIMM, Front View
Key notch
Plastic cover