Sun Microsystems SPARCstation 20 - System Board

196 SPARCstation 20 Service Manual • July 1996
The following are located on the system board:
■ MBus module (two maximum)
■ SBus card (four maximum)
Note – A maximum of four SBus cards may be installed unless optional VSIMM/
AVB is installed, in which case a maximum of three SBus cards may be installed.
■ Main Memory
■ DSIMM (eight maximum)
■ VSIMM (two maximum, in conjunction with up to six DSIMMs)
■ NVSIMM (one maximum, in conjunction with a second VSIMM and five
DSIMMs)
Note – Installing a second VSIMM and NVSIMM reduces the maximum number of
DSIMMs to six.
■ AVB (one maximum, used with a second VSIMM)
System Board
FIGURE B-1 shows a block diagram of the SPARCstation 20 system board.