SDK v21.0.0

Breaking changes

• #383 - neo6502 - Update API bindings - @asiekierka
  • Split neo_controller_read(void) into neo_controller_read_default(void) and neo_controller_read(uint8_t index)
  • Renamed some enum values

New features

• #383 - neo6502 - Add new APIs bindings - @asiekierka

Bug fixes

• #383 - neo6502 - Fix UExt functions - @asiekierka
• #384 - cpm65 - Fix some minor CP/M-65 issues - @davidgiven