Zx Spectrum Test Program Link !full!

: A highly regarded tool for the original 16K/48K and later 128K models. It tests RAM, ROM, keyboard, sound, video, and various ULA/Z80 features. Manual & Details Retroleum Diagnostic ROM Documentation Sinclair Test ROM (1983)

: One of the most popular community-created diagnostic tools. It can identify specific bad bits in RAM through on-screen messages and beep codes. Download : Retroleum DiagROM v1.71 zx spectrum test program link