Zx | Spectrum Test Program

ld hl, 32768 ; start of 32K RAM area (for 48K) ld de, 32769 ld bc, 32768-1 ld (hl), $FF ldir ; fill with $FF ; ... then verify and repeat with $00, $AA, $55

Just finished a little weekend project – a bare-bones ZX Spectrum diagnostic/test program written in Z80 assembly. Thought I’d share it for anyone restoring old rubber-keyed Speccys or building a clone (like a Harlequin or ZX-UNO). zx spectrum test program

Here’s a retro-computing style post for a forum, social media, or blog, depending on where you want to share it. Building a Simple Test Program for the ZX Spectrum – Check RAM, ROM, and Keyboard in under 1KB ld hl, 32768 ; start of 32K RAM