Comment by isthisnametaken

No, the Master followed the BBC Micro architecture, which was 32K RAM followed by 32K ROM, made up of 16K paged ROM then 16K of OS and memory mapped peripherals. The other 96K that made up the 128 was 64K in sideways RAM (which could be paged into the pages ROM area, 20K that could be paged over the top of the RAM (where the screen data would live) and 12K that could be paged over parts of the OS ROM.