Zx Spectrum Next: Memory

In Zx Spectrum Next there is a lot of RAM. The RAM is divided into 16Kb banks with 256K reserved for ROMs and DivMMC interface, so in practice we have 48 banks in Next 1MB version or 112 banks in Next 2MB version mapped as follow:

Bank # Description
0..7 same as standard Spectrum 128K
8..47 available on all Next
48..111 available only on Next 2MB version

NextZXOS uses the first 9 banks. Banks starting at 9 are always available to the programmer

Bank # Description
0 standard Spectrum 48K (addr. 49152..65535)
1 RAMdisk
2 standard Spectrum 48K (addr. 32768..49151)
3 RAMdisk
4 RAMdisk
5 standard Spectrum 48K (addr. 16384..32767)
6 RAMdisk
7 Workspace and data structures
8 additional screen data on some video modes

Source: https://gitlab.com/thesmog358/tbblue/-/blob/master/docs/nextzxos

Some new Basic commands

  • BANK NEW var
  • BANK n ERASE value
  • BANK n ERASE offset,len
  • BANK n ERASE offset,len,value
    • Fill len byte in bank n with value starting at offset