This listing is for ZX Spectrum external diagnostic ROM, ideal for analysis of faulty ZX Spectrum machines

- available diagnostic ROMs are selectable with DIP switch

    Retroleum DiagROM v1.56   - https://www.retroleum.co.uk/diagrom/diagrom.pdf

    Brendan Alford diagnostics v0.37   - https://github.com/brendanalford/zx-diagnostics/wiki/Firmware

  

- works with ZX SPECTRUM 16k/48K/48K+/128k/+2

- four supply indication LEDs (+5V, +9V, -5V, -12V) for quick power failure diagnosis

- small and compact design

- reset button