"Joel" wrote: > "Greg Andrzejewski" wrote in message > news:Us6dnZzGusZHgG2gXTWcpA@comcast.com... > > I'm looking to add more ram to my ROM 1 gs. Right now I have the standard > > 1mb Apple IIgs ram expansion card 670-2500-A. What cards are available for > > upgrading ram above 1mb? Could the chips on the card I have now be used to > > fill an unpopulated card? Please help. Thanks. > > > Let me add a little to what David said. > > ROM0/1 and ROM3 motherboards have different base addresses for RAM > expansion. > ROM0/1 starts at 256k, ROM3 at 1M. ROM 00/01 actually starts at 128KB. The 256KB of built in RAM consists of "fast" banks $00 and $01, and "slow" banks $E0 and $E1. The memory expansion card provides additional "fast" RAM starting at bank $02, and limited to bank $7F by the hardware and the Memory Manager toolset. The card can add 7.875 MB ("seven and seven eighths"). ROM 3 starts at 1 MB (bank $10) as you mentioned, but has the same limit of bank $7F, so you can only add 7 MB of RAM via the memory expansion slot. -- David Empson dempson@actrix.gen.nz