jgraves@graves (John Graves) (05/22/91)
If you must remove or install memory on a NeXTstation Color, here are some tips: DRAM is arranged in four banks of two 72 pin SIMMs each. Each SIMM pair may contain 0, 2, or 8 MB of memory. The two SIMMs in each pair must be the same size (1 or 4 MB). DRAM must always be installed in the two SIMM sockets nearest the edge of the cpu board as this corresponds to the address space where the mach kernel loads into during boot. All SIMMs must be parity type to use parity. Parity and non-parity SIMMS may be mixed or parity disabled if the parity option in the ROM monitor "p" command is used. Black SIMM sockets: To remove a SIMM, gently squeeze the white tab up using needle nose pliers, then pull up on that edge of the SIMM. When installing SIMMs, press them firmly into the socket to seat the connectors. Check to see that all SIMMs are evenly seated in their sockets. White SIMM sockets: To remove a SIMM, release the latch on each side of the SIMM using a pointed instrument, then tilt (VERY IMPORTANT!!!) the SIMM toward the edge of the board, lifting it out. Do NOT pry the SIMM straight up, as it will break the latches off and destroy the socket. Some SIMMs may have to be removed or tilted temporarily to add more memory, as each SIMM must have room to tilt to the side. When installing SIMMs, check to see that all SIMMs are evenly seated in their sockets with the latches in the locked position. If a DSP expansion memory SIMM is installed, the component side of the SIMM should be facing toward the SCSI drive, not the VRAMs. If a DSP SIMM is installed backward (by force), the computer will not power up. John Graves NeXT Computer, Inc