like the Atari 130XE. Probably more, actually, since it's an emulator running on a Rasberry Pi derivitive. I don't recall anything after the Atari 400/800 released in 1979 that had memory expansion slots, other than ROM cartridge slots. However, the Atari 8-bit line didn't last as long as the Commodore 8-bit line, so 128K wasn't too bad. Remember the original Apple Macintosh released with just 128K. But by the end of the decade, operating systems and applications were demanding more and more memory.
BTW, the Commodore 64 didn't see any real memory expansion that mapped memory to the CPU, the CPU can only see 64K of RAM and ROM at once time. Memory expansion, such as the 1764, 1700, 1750, and the CMD RAMlink were just RAMDisks. The 17-series contained the REU chip, an equivelant to the Amiga Blitter chip that can transfer from the RAM expansion to local memory very quickly, and can do it without interrupting the 6510 CPU. It can do it even faster with the VIC II turned off. As it shared an interrupt with the VIC II chip to operate. The new Ultimate 64 and The64 mini/maxi have this build in, as well as the 1541 Ultimate II+ I use with my Commodore 64-SX, which gives a much bigger platform for game design than the old stock Commodore 64, While still being compatible with all of Commodore 64's existing massive library. So we're seeing much bigger games now, than we had in the past, as well as old games that were very disk-intensive, like Ultima IV that requires swapping 4 disks constantly to play, can now be stored on a single 1581 image that load to REU memory, or a Easyflash3 cartridge format that works like an REU but with ROM instat of RAM, so there's virtually no loading times. I need to investigate, still if there's something like Easyflash3 for the Atari. which is 1 MB ROM images. 1 MB seems small today, but for those 8-bit computers it's huge.