196 SPARCstation 20 Service Manual • July 1996
The following are located on the system board:
â– MBus module (two maximum)
â– 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.
â– Main Memory
â– DSIMM (eight maximum)
â– VSIMM (two maximum, in conjunction with up to six DSIMMs)
â– 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.
â– AVB (one maximum, used with a second VSIMM)
System Board
FIGURE B-1 shows a block diagram of the SPARCstation 20 system board.